What is an overgrowth of fibrous tissue, usually produced at the site of a scar?

Keloid Scar of Skin: Symptoms, Causes, and Treatments Keloid Scar of Skin Email addresses will not be shared with 3rd parties. See privacy policy Thank you. Your message has been sent. OK We're sorry, an error occurred. We are unable to collect your feedback at this time. However, your feedback is important to us. Please try again later. Close Key points Keloids are smooth, hard, benign growths that form when scar tissue grows excessively. Risk factors include being of African, Asian, or Latino heritage, being pregnant, and being younger than 30 years old. Treatments for keloid scarring are not always effective. When skin is injured, fibrous tissue, called scar tissue, forms over the wound to repair and protect the injury. In some cases, scar tissue grows excessively, forming smooth, hard growths called keloids. Keloids can be much larger than the original wound. They’re most commonly found on the chest, shoulders, earlobes, and cheeks. However, keloids can affect any part of the body. Although keloids aren’t harmful to your health, they may create cosmetic concerns. Picture What symptoms are associated with keloids? Keloids occur from the overgrowth of scar tissue. Symptoms occur at a site of previous skin injury. The symptoms of keloids can include: a localized area that is flesh-colored, pink, or red in color a lumpy or ridged area of skin that’s usually raised an area that continues to grow larger with scar tissue over time an itchy patch of skin Keloid scars tend to be larger than the original wound itself. They may take weeks or months to develop fully. While keloid scars may be itchy, they’re usually not harmful to your health. You may experience discomfort, tenderness, or possible irritation from your clothing or other forms of friction. In rare instances, you may experience keloid scarring on a significant amount of your body. When this occurs, the hardened, tight scar tissue may restrict your movements. Keloids are often more of a cosmetic concern than a health one. You may feel self-conscious if the keloid is very large or in a highly visible location, such as an earlobe or on the face. Sun exposure or tanning may discolor the scar tissue, making it slightly darker than your surrounding skin. This can make the keloid stand out even more than it already does. Keep the scar covered when you’re in the sun to prevent discoloration. What causes the condition? being pregnant being younger than 30 Keloids tend to have a genetic component, which means you’re more likely to have keloids if one or both of your parents has them. According to a study conducted at Henry Ford Hospital in Detroit, Michigan, a gene known as the AHNAK gene may play a role in determining who develops keloids and who doesn’t. The researchers found that people who have the AHNAK gene may be more likely to develop keloid scars than those who don’t. If people have known risk factors for developing keloids, they may want to avoid getting body piercings, unnecessary surgeries, or tattoos. When to seek medical attention Keloids typically don’t require medical attention, but you may want to contact your doctor if growth continues, you develop additional symptoms, or you want to have the keloids surgically removed. Keloids are benign, but uncontrolled growth may be a sign of skin cancer. After diagnosing keloid scarring by visual exam, your doctor may want to perform a biopsy to rule out other conditions. This involves taking a small sample of tissue from the scarred area and analyzing it for cancerous cells. Find a Doctor How is the condition treated? The decision to treat a keloid can be a tricky one. Keloid scarring is the result of the body’s attempt to repair itself. After removing the keloid, the scar tissue may grow back again, and sometimes it grows back larger than before. Examples of keloid treatments include: corticosteroid injections to reduce inflammation moisturizing oils to keep the tissue soft using pressure or silicone gel pads after injury freezing the tissue to kill skin cells laser treatments to reduce scar tissue radiation to shrink


Which is the only vein in the body to carry oxygenated blood?

Why does the pulmonary vein carry oxygenated blood instead of de-oxygenated blood? - Quora Why does the pulmonary vein carry oxygenated blood instead of de-oxygenated blood? Written Sep 12, 2015 The idea that veins only carry deoxygenated blood is an oversimplification and it's clearly not completely true. That's not what makes a vein a vein. Veins are less muscular than arteries, carry blood back toward the heart from the body, and contain valves. The pulmonary vein carries oxygenated blood because it is carrying blood back from the lungs, where it picked up oxygen. Written Sep 19, 2015 The definition of a vein is that it brings blood back towards the heart, and it so happens that blood coming back to the heart from the lungs are filled with oxygen, which is exactly what lungs were meant to do. The same goes for umbilical veins that actually carry oxygenated blood from the placenta back to the growing foetus. And since the flow back to the heart is usually passive (i.e. not pumped), veins have other common characteristics such as having thinner walls (because of lower pressures), valves (preventing reflux), are compressible, etc.


Which human body organ weighs about 2 kilos?

≡ List of Human Organs + All Sizes, Functions, Tasks, Weights & Facts 23.8 Over the skeleton around the body At up to 1.95 square meters (21 sq ft) The “derma” is the largest of all human organs and one of the heaviest weighing between 6-10% of body weight. Oil glands stop skin drying out. Skin cells are continuously shedded and replaced. Skin is a versatile organ with an ideal pH value of 5.5. Responds to external stimuli (touch, heat) and uses sweat to cool the body and raised hairs (goosebumps) to trap heat and warm the body regulating the overall temperature. Protects us from UV radiation and injury by producing thick skin (calluses). Liver 3.1 Upper right abdominal cavity just beneath the diaphragm Largest gland in the body. The “Iecur” or “hepar” has a soft smooth surface, left and right lobes and weighs between 1.4-2 kg (3-4.4 lbs). The tissue consists of around 100,000 lobules. Stores energy reserves ( vitamins and carbohydrates), detoxifies and breaks down nutrients, produces vital proteins (clotting factors). Brain 3.0 Inside the skull The female “cerebrum” weighs around 1.2 kg (2.8 lbs) compared to 1.4 kg (3 lbs) for males. The brain consumes between 20-25% of our total energy intake. The brain consists of 100 billion neurons (somata) and 100 trillion synapses. The neural pathways are 5.8 km (3.6 miles) long in total. We distinguish between: cerebrum, cerebellum, diencephalon and trunk. Processes sensory inputs, coordinates behavior and saves information; cerebrum (perception, thinking, acting), diencephalon (feelings like love, fear, anger etc.), cerebellum (balance while walking, running, dancing etc). Lungs 2.4 Inside chest rib cage The “pulmo” typically weighs just over 1kg (2.2 lbs) and has a volume between 5-6 liters (10.5-12.7 US pints) with 400 million alveoli. The (smaller) left lung consists of two lobes, the right one of three lobes. Gas exchange between air and bloodstream. In other words absorption of oxygen and release of carbon dioxide from the body. Heart 0.8 Under ribcage between your left and right lungs The “cor” or “cardia” is a fist-sized, hollow, muscular human organ weighing between 300-350g (10-12 oz), the right and left side of the heart each consist of a chamber and an atrium. Of all the human organs the heart is most impressive. At rest it can pump 4.9 liters of blood per minute through our veins. Under duress this can rise to between 20-25 liters of blood per minute. Kidney 0.7 Under ribcage in lower back Both kidneys (“ren” or “nephros”) weigh about 300 g (10½ oz). Between them the 1.2 million renal corpuscles filter up to 1500 liters (400 US gallons) of blood daily. Purifies the blood and filters out toxins from the body, controls the water balance of the body, excretion of waste products through urine production. Spleen 0.4 Below rib cage on your left side The spleen is about the size of a fist and weighs between 150 and 200 grams (5-7 oz). It’s located on the abdomen on the left kidney and below the diaphragm. Produces red and white blood cell pulp helping the immune system fight infections. Pancreas 0.22 Behind stomach in abdomen Wedge shaped organ between 16-20 cm long, 3-4 cm wide and up to 2 cm (3/4″) thick. Weighs around 100 grams (3½ oz). The pancreas is a dual function organ which produces enzymes to digest our stomach contents, separating fats, proteins and carbs. The pancreas also regulates blood sugar by producing two hormones, insulin and glucagon which have opposite effects. Thyroid 1.65 Immediately above and behind the pubic bone The “vesica urinaria” holds up to 550 ml (1.2 US pints) of urine (or with some men even up to 750 ml (1.6 US pints) Ureters connect the kidneys to the bladder and transport the purified blood (urine) to the bladder. Stores the urine resulting from the blood purification in the kidneys and removes all toxins (urea, chlorides, sodium, potassium, creatine, bicarbonate, uric acid) from the body through excretion. Blood   In blood vessels (arteries, veins, capillaries etc.) An average 5-7 liters (10.6-14.8 US pints) of “Sanguis” flows through ou


Which name is given to the heart chamber which receives blood?

Chambers of the Heart Chambers of the heart Chambers of the heart The heart has four chambers: two atria and two ventricles. The right atrium receives oxygen-poor blood from the body and pumps it to the right ventricle. The right ventricle pumps the oxygen-poor blood to the lungs . The left atrium receives oxygen-rich blood from the lungs and pumps it to the left ventricle. The left ventricle pumps the oxygen-rich blood to the body. Credits Primary Medical ReviewerWilliam H. Blahd, Jr., MD, FACEP - Emergency Medicine Adam Husney, MD - Family Medicine Specialist Medical ReviewerDavid Messenger, MD H. Michael O'Connor, MD - Emergency Medicine Martin J. Gabica, MD - Family Medicine Current as ofOctober 1, 2015 WebMD Medical Reference from Healthwise This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.© 1995-2015 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated. Top Picks


Hip Joint - Anatomy Pictures and Information Hip Joint Home > Skeletal System > Bones of the Leg and Foot > Hip Joint Hip Joint The hip joint is one of the most important joints in the human body. It allows us to walk, run, and jump. It bears our body’s weight and the force of the strong muscles of the hip and leg. Yet the hip joint is also one of our most flexible joints and allows a greater range of motion than all other joints in the body except for the shoulder. The hip joint is a ball-and-socket synovial joint formed between the os coxa (hip bone) and the femur. A round, cup-shaped structure on the os coax, known as the acetabulum, forms the socket for the hip joint. The rounded head of the femur... Move up/down/left/right: Click compass arrows Rotate image: Click and drag in any direction, anywhere in the frame Identify objects: Click on them in the image 2D Interactive 3D Rotate & Zoom Change Anatomical System Full Hip Joint Description [Continued from above] . . . forms the ball of the joint. Hyaline cartilage lines both the acetabulum and the head of the femur, providing a smooth surface for the moving bones to glide past each other. Hyaline cartilage also acts as a flexible shock absorber to prevent the collision of the bones during movement. Between the layers of hyaline cartilage, synovial membranes secrete watery synovial fluid to lubricate the joint capsule. Surrounding the hip joint are many tough ligaments that prevent the dislocation of the joint. The strong muscles of the hip region also help to hold the hip joint together and prevent dislocation. Functionally, the hip joint enjoys a very high range of motion. The ball-and-socket structure of the joint allows the femur to circumduct freely through a 360-degree circle. The femur may also rotate around its axis about 90 degrees at the hip joint. Only the shoulder joint provides as high of a level of mobility as the hip joint. In addition to being flexible, each hip joint must be capable of supporting half of the body’s weight along with any other forces acting upon the body. During running and jumping, for example, the force of the body’s movements multiplies the force on the hip joint to many times the force exerted by the body’s weight. The hip joint must be able to accommodate these extreme forces repeatedly during intense physical activities. If a knee or hip joint breaks in an accident or wears out in old age, a surgeon can replace it with a ball-and-socket joint made from metal and plastic and engineered in such a way that it will duplicate the motions of a human joint. Hip replacement was once impossible because, although joints could easily be produced in a laboratory, the human body rejected the materials. Sometimes the pins that held the artificial joint to other bones worked loose and required further surgery. Some joints, especially the artificial knee, didn't work very well because they were designed like hinges that just opened one way. Later, when the designers realized the knee needed to rotate slightly, they produced a joint that would fulfill these movements as well. Medical pioneers finally overcame bodily rejection by making the joints out of non-irritating, man-made materials. Surgeons have now perfected hip and knee replacement surgeries so that recipients are relieved of pain and can walk at a smoother pace. Prepared by Tim Taylor, Anatomy and Physiology Instructor


The Sinoatrial Node | Pacemaker of the heart Sinoatrial Node The SA node (sinoatrial node) is a collection of tissue located in the hearts right atrium. This tissue, like all of the cells in the heart, is capable of producing electrical impulses. The unique function of the SA node however, is that it acts as the pacemaker for the heart. For a normal heart, the SA node initiates an electrical impulse causing the heart to beat. This is why a normal heart rhythm is known as a Sinus rhythm. In the event that the sinoatrial node does not work, the heart is very resilient, and will use the AV node as the primary pacemaker. If the AV node also fails, then the Purkinje cells will function as the hearts pacemaker. When the SA node is not functioning correctly, though the hearts rate may be controlled by either the AV node or the Purkinje cells, the heart rate will typically be abnormal. There are a number of arrhythmias that can be attributed to a problem with the SA node. Commonly you may see sinus bradycardia or sinus tachycardia. There are also a number of heart block issues that may be attributed to issues with the sinus node. These heart block issues include; SA node Wenckebach, SA node Mobitz II, and SA node exit block. Issues associated with the SA node can usually be diagnosed with an electrocardiogram, which is looking at the hearts electrical function. When the SA node can no longer effectively act as the pacemaker for the heart, an artificial pacemaker may be used to control the hearts electrical system. Advanced Cardiac Life Support ( ACLS ) looks at the various conditions that can affect the SA node, and deals with diagnosis, treatment paths, and pharmacology for these various conditions. Most medical professionals that deal with the cardiovascular system, or function as emergency response have ACLS certification , to ensure they can properly deal with SA node and other heart problems. The SA node is both controlled and influenced by both the parasympathetic nervous system and the sympathetic nervous system. This control/influence can adjust both the heart rate, and force of contractions. So while the heart beat occurs without conscious effort, it can also be influenced by your surroundings. For example, your heart rate will increase with exercise, slow down while you're sleeping, or increase in preparation for a fight or flight situation. The SA node is supplied blood from the SA node artery, but can still be affected during myocardial infarction which can cause death to the SA node cells. This may cause a deficiency in the SA node's ability to act as a pacemaker, and can also lead to sick sinus syndrome. © sinoatrialnode.net


What is the substance that the body over-produces in an allergic reaction to pollen?

What Exactly Is an Allergy? Insect Allergies What is Happening During an Allergic Reaction? During an allergic process, the substance responsible for causing the allergy , or allergen, binds to allergic antibodies present on allergic cells in a person's body, including mast cells and basophils. These cells then release chemicals such as histamine and leukotrienes, resulting in allergic symptoms. How do Allergies Start? The allergic person can make allergic antibodies, or IgE, against a variety of allergens, including pollens , molds, animal danders, dust mites, foods, venoms and medications. This occurs through a process called sensitization, where a person’s immune system is exposed to enough of the allergen to make the body produce allergic antibodies to that substance. With later exposures, that same allergen binds to its corresponding IgE on allergic cells, and the body reacts with symptoms of allergies. Allergic symptoms can vary somewhat with the type of allergen and route of exposure (airborne pollen exposure may cause different symptoms than eating a food to which you are allergic). When and Why do People Develop Allergies? It is unknown why some people develop allergies and some don’t. Allergies seem to run in families, and in some cases, family members can share allergies to specific foods or medications. It appears that the allergic response was once meant to protect the body against parasitic infections, although now seems to be an abnormal response to non-infectious triggers. Allergies can occur at any time during our lives, but are more common to occur during childhood or young adulthood.


Which organ of the body secretes insulin?

How Insulin Works in the Body How Insulin Works in the Body Search the site By Elizabeth Woolley - Reviewed by a board-certified physician. Updated November 14, 2016 Insulin has a hand in several processes in your body: Not only does it assist with metabolizing carbohydrates and storing glucose for energy in cells, but it also helps utilize the fat, protein, and certain minerals you eat. Because this hormone is so important in helping your body use the foods you ingest, a problem with insulin can have widespread effects on all of your body's systems, tissues, and organs—either directly or indirectly. If you have type 2 diabetes, learning how insulin works can help you understand why so many other medical conditions are associated with diabetes, why certain lifestyle practices are beneficial, and how your body reacts to food. Where Insulin is Produced in the Body Insulin is a hormone made up of a small polypeptide protein that is secreted by the pancreas, which acts as both an endocrine and exocrine gland. Endocrine glands are the system of glands that secrete hormones to regulate body functions. Exocrine glands aid in digestion. The pancreas sits behind the stomach, nestled in the curve of the duodenum (the first part of the small intestine), and contains clusters of cells called islets of Langerhans. Islets are made up of beta cells, which produce and release insulin into the bloodstream. Insulin is Part of a Balancing Act Insulin affects carbohydrate, protein, and fat metabolism. Your body breaks these nutrients down into sugar molecules, amino acid molecules, and lipid molecules, respectively. The body can also store and reassemble these molecules into more complex forms. Insulin causes the storage of these nutrients, while another pancreatic hormone called glucagon releases them from storage. Insulin is involved in your body's careful balancing act to keep your blood sugar levels within a normal range. In simple terms: If your blood sugar is high: The pancreas releases insulin to help cells absorb glucose from the bloodstream to lower blood sugar levels. If your blood sugar is low: The pancreas releases glucagon to help the liver release stored glucose into the bloodstream to raise blood sugar levels. Blood sugar levels rise when most foods are consumed, but they rise more rapidly and drastically with carbohydrates. The digestive system releases glucose from foods and the glucose molecules are absorbed into the bloodstream. The rising glucose levels signal the pancreas to secrete insulin to clear out glucose from the bloodstream. Insulin binds with insulin receptors on cell surfaces and acts as a key to open up the cells to receive glucose. Insulin receptors are on almost all tissues, including muscle cells and fat cells. Insulin receptors have two main components—the exterior and interior portions. The exterior portion extends outside the cell and binds with insulin. When this happens, the interior part of the receptor sends out a signal inside the cell for glucose transporters to mobilize to the surface and receive glucose. As blood sugar and insulin levels decrease, the receptors empty and the glucose transporters go back into the cell. Insulin and Type 2 Diabetes In a perfect situation, glucose from carbohydrates gets cleared rapidly. However, when there is insulin resistance , this does not happen, and sustained high glucose levels become a problem. Insulin resistance can be due to a problem with the shape of the insulin (preventing receptor binding), not having enough insulin receptors, signaling problems, or glucose transporters not working properly. Whatever the specific cause, the function of insulin is impaired. Insulin resistance develops before type 2 diabetes is diagnosed. To make up for less effective insulin, the pancreas works overtime to increase insulin output. Eventually, some of the insulin works and blood sugar levels remain normal for a while. As insulin resistance worsens and the pancreas cannot keep up with the demand, glucose levels begin to rise and diabetes is diagnosed when levels get too


Which part of the gut absorbs water from thje food?

Absorption of Water and Electrolytes Glossary Absorption of Water and Electrolytes The small intestine must absorb massive quantities of water. A normal person or animal of similar size takes in roughly 1 to 2 liters of dietary fluid every day. On top of that, another 6 to 7 liters of fluid is received by the small intestine daily as secretions from salivary glands, stomach, pancreas, liver and the small intestine itself. By the time the ingesta enters the large intestine, approximately 80% of this fluid has been absorbed. Net movement of water across cell membranes always occurs by osmosis , and the fundamental concept needed to understand absorption in the small gut is that there is a tight coupling between water and solute absorption. Another way of saying this is that absorption of water is absolutely dependent on absorption of solutes, particularly sodium: Sodium is absorbed into the cell by several mechanisms, but chief among them is by cotransport with glucose and amino acids - this means that efficient sodium absorption is dependent on absorption of these organic solutes. Absorbed sodium is rapidly exported from the cell via sodium pumps - when a lot of sodium is entering the cell, a lot of sodium is pumped out of the cell, which establishes a high osmolarity in the small intercellular spaces between adjacent enterocytes. Water diffuses in response to the osmotic gradient established by sodium - in this case into the intercellular space. It seems that the bulk of the water absorption is transcellular, but some also diffuses through the tight junctions. Water, as well as sodium, then diffuses into capillary blood within the villus. Examine the animation above and consider the osmotic gradient between the lumen and the intercellular space (inside the villus). As sodium (green balls) is rapidly pumped out of the cell, it achieves very high concentration in the narrow space between enterocytes. The osmotic gradient is thus formed across apical cell membranes and their connecting junctional complexes. The arrow that appears denotes movement of water across the epithelium. Water is thus absorbed into the intercellular space by diffusion down an osmotic gradient. However, looking at the process as a whole, transport of water from lumen to blood is often against an osmotic gradient - this is important because it means that the intestine can absorb water into blood even when the osmolarity in the lumen is higher than osmolarity of blood. This ability is best explained by the " three compartment model " for absorption of water and, like many aspects of gut permeability, varies along the length of the gut. The proximal small intestine functions as a highly permeable mixing segment, and absorption of water is basically isotonic. That is, water is not absorbed until the ingesta has been diluted out to just above the osmolarity of blood. The ileum and especially the colon are able to absorb water against an osmotic gradient of several hundred milliosmols.


Where would you find the islets of Langerhans?

Definition of Islets of Langerhans Definition of Islets of Langerhans Causes of a Heart Attack Slideshow Islets of Langerhans: Known as the insulin -producing tissue, the islets of Langerhans do more than that. They are groups of specialized cells in the pancreas that make and secrete hormones. Named after the German pathologist Paul Langerhans (1847-1888), who discovered them in 1869, these cells sit in groups that Langerhans likened to little islands in the pancreas. There are five types of cells in an islet: alpha cells that make glucagon , which raises the level of glucose (sugar) in the blood; beta cells that make insulin; delta cells that make somatostatin which inhibits the release of numerous other hormones in the body; and PP cells and D1 cells, about which little is known. Degeneration of the insulin-producing beta cells is the main cause of type I (insulin-dependent) diabetes mellitus. Last Editorial Review: 5/13/2016


What is the colored muscle that responds involuntarily to light?

Pupil: Light, Perception & Life Science Activity | Exploratorium Teacher Institute Project None needed. To Do and Notice Place the magnifying glass on the surface of the mirror. Look into the center of the magnifying glass with one eye. If you wear contact lenses or glasses, you may either leave them on or remove them. Adjust your distance from the mirror until you see a sharply focused and enlarged image of your eye. You may need to adjust the position of the magnifier to get the clearest image of your eye. Notice the white of your eye, the colored disk of your iris, and your pupil, the black hole in the center of your iris. Shine a light into the pupil of one eye. If you are using a small mirror, hold the flashlight behind the mirror and shine the light around the edge of the mirror into your eye. If you are using a large mirror, bounce the flashlight beam off the mirror into your eye. Observe how your pupil changes size. Notice that it takes longer for your pupil to dilate than it does to contract. Notice also that the pupil sometimes overshoots its mark. You can see it shrink down too far, and then reopen slightly. Observe changes in the size of one pupil while you, or a partner, shine a light into and away from the other eye. In a dimly lit room, open and close one eye while observing the pupil of the other eye in the mirror. What's Going On? The pupil is an opening that lets light into your eye. Since most of the light entering your eye does not escape, your pupil appears black. In dim light, your pupil expands to allow more light to enter your eye. In bright light, it contracts. Your pupil can range in diameter from 1/16 inch (1.5 mm) to more than 1/3 inch (8 mm). Light detected by the retina of your eye is converted to nerve impulses that travel down the optic nerve. Some of these nerve impulses go from the optic nerve to the muscles that control the size of the pupil. More light creates more impulses, causing the muscles to close the pupil. Part of the optic nerve from one eye crosses over and couples to the muscles that control the pupil size of the other eye. That’s why the pupil of one eye can change when you shine the light into your other eye. In this experiment, the light reflecting from your eye passes through the magnifying lens twice—once on its way to the mirror and once on its way back. Therefore, the image of your eye is magnified twice by the magnifying glass. Going Further The size of your pupils actually reflects the state of your body and mind. Pupil size can change because you are fearful, angry, in pain, in love, or under the influence of drugs. Not only does the pupil react to emotional stimuli, it is itself an emotional stimulus. The size of a person’s pupils can give another person a strong impression of sympathy or hostility. The response of the pupil is an involuntary reflex. Like the knee-jerk reflex, the pupillary response is used to test the functions of people who might be ill or injured. You may have seen a doctor shine light into the eyes of a person with a suspected head injury—they are looking at the pupillary response. The pupil of your eye is also the source of the red eyes you sometimes see in flash photographs. When the bright light of a camera flash shines directly through the pupil, it can reflect off the choroid, which supplies red blood to the retina (the light-sensitive lining at the back of your eye), and bounce right back out through the pupil. If this happens, the person in the photograph will appear to have glowing red eyes. To avoid this, photographers move the flash away from the camera lens. With this arrangement, the light from the flash goes through the pupil at an angle, illuminating a part of the retina not captured by the camera lens. Many cameras are equipped with red-eye reduction features, such as a pre-flash that causes pupil constriction before the actual flash that illuminates the photo. Related Snacks


What is the name of the enzyme produced in the mouth?

Names of the Enzymes in the Mouth & Esophagus | The Classroom | Synonym Names of the Enzymes in the Mouth & Esophagus by Andrea Becker The enzymes in your saliva start the digestion process when you put food in your mouth. Related Articles How Does Temperature Affect Metabolism? You might think of the stomach or the intestines when you think of digestive enzymes, but the process of digestion starts the moment food enters your mouth. The mouth and esophagus themselves don’t produce any enzymes, but saliva, produced in the salivary glands and excreted into the mouth, contains several important enzymes. Saliva is mixed with food as you chew, acting as a lubricant and starting the digestion process. The enzymes in saliva start to break down nutrients and protect you from bacteria. Salivary Amylase One of the primary enzymes in saliva is amylase. Amylase starts to break down starches in the food you eat. Starches are long chains of sugars attached to each other, and amylase breaks the bonds along the chain to release maltose sugar molecules. To experience amylase in action, chew on a cracker for a minute and you will find that it starts to taste sweet. Amylase functions in a neutral to slightly basic environment, which is definitely not to be found in the acid bath that is your stomach. Lysozyme Secretion Lysozyme is secreted in your tears, the mucus in your nose and your saliva. Lysozyme isn’t there to digest your food, it is there to protect you from any harmful bacteria that came with it. Lysozyme breaks down the polysaccharides in the cell walls of many bacteria. Once the cell wall has been broken down, a bacterium dies, bursting like a water balloon. In scientific terms, cell death by popping is known as lysis, so the enzyme that accomplishes the task is called lysozyme. Lingual Lipase Lingual lipase is an enzyme that breaks down fats, specifically triacylglycerols. It is excreted as part of saliva, but it doesn’t finish its job until it gets to the stomach. The amount of lingual lipase in your saliva decreases as you get older, and gastric and pancreatic lipase lower down in your digestive system take over the job of digesting fats. Lingual lipase is very important for infants because it helps them digest the fats in milk, making digestion much easier for their immature systems. Salivary Kallikrein Kallikrein is the name for a group of proteases, enzymes that break down proteins, which are found throughout the body, including trace amounts in the saliva. The function of salivary kallikrein is not to digest the proteins you consume, however. Salivary kallikrein breaks down very specific proteins with a high molecular weight to produce bradykinin, a protein that helps blood vessels dilate. Changes to kallikrein enzymes have also been linked to certain cancers. References


The pituitary controls many hormones, but what controls the pituitary?

You & Your Hormones | Glands | Pituitary gland You & Your Hormones   Email article to a friend | Last updated: January 21, 2015 The pituitary gland is a small pea-sized gland that plays a major role in regulating vital body functions and general wellbeing. It is referred to as the body’s ‘master gland’ because it controls the activity of most other hormone-secreting glands. Computer artwork of a person's head showing the left hemisphere of the brain inside. The highlighted area (centre) shows the pituitary gland attached to the bottom of the hypothalamus at the base of the brain. Alternative names Hypophysis. Where is my pituitary gland? The pituitary gland is a pea-sized gland. It sits in the sella turcica (‘Turkish saddle’), a bony hollow in the base of the skull, underneath the brain and behind the bridge of the nose. Although the pituitary gland looks like one gland, it actually has two distinct parts, the anterior pituitary gland and the posterior pituitary gland. The gland is attached to the hypothalamus , the part of the brain that controls its activity. The anterior part of the pituitary gland consists of gland cells, which are connected to the brain by very short blood vessels. The posterior pituitary gland is actually part of the brain and it secretes hormones directly into the bloodstream under the command of the brain.  What does my pituitary gland do? The pituitary gland is called the ‘master gland’ as the hormones it produces control so many different processes in the body. It senses the body’s needs and sends signals to different organs and glands throughout the body to regulate their function and maintain an appropriate environment. It secretes a variety of hormones into the bloodstream which act as messengers to transmit information from the pituitary gland to distant cells, regulating their activity. For example, the pituitary gland produces prolactin , which acts on the breasts to induce milk production. The pituitary gland also secretes hormones that act on the adrenal glands , thyroid gland , ovaries and testes , which in turn produce other hormones. Through production of its hormones, the pituitary gland controls metabolism , growth, sexual maturation, reproduction, blood pressure and many other vital physical functions and processes. What hormones does my pituitary gland produce? The anterior pituitary gland produces the following hormones and releases them into the bloodstream: Adrenocorticotropic hormone , which stimulates the adrenal glands to secrete steroid hormones, principally cortisol   Thyroid stimulating hormone , which stimulates the thyroid gland to secrete thyroid hormones. There are also some hormones that are produced by the hypothalamus and then stored in the posterior pituitary gland prior to being released into the bloodstream. These are: Anti-diuretic hormone , which controls water balance and blood pressure. It is made by the hypothalamus but is stored in the posterior pituitary gland prior to being released into the bloodstream.   Oxytocin , which stimulates uterine contractions during labour and milk secretion during breastfeeding. It is made by the hypothalamus but is stored in the posterior pituitary gland prior to being released into the bloodstream. Each of these hormones is made by a separate type of cell within the pituitary gland, except for follicle stimulating hormone and luteinising hormone, which are made together by the same cell.  What could go wrong with my pituitary gland? The pituitary gland is an important gland in the body and the hormones it produces carry out varied tasks and regulate the function of many other organs. This means that the symptoms experienced when the pituitary gland stops working correctly can be varied depending on which hormone is affected.    Conditions that affect the pituitary gland directly can be divided into three main categories: Conditions that cause the pituitary gland to produce too much of one or more hormone(s). Examples include acromegaly , Cushing's disease and prolactinoma .   Conditions that cause the pituitary gland to p


Hyperpigmentation and Hypopigmentation: Albinism, Vitiligo, and More Pigmentation is the coloring of a person's skin . When a person is healthy, his or her skin color will appear normal. In the case of illness or injury, the person's skin may change color, becoming darker (hyperpigmentation) or lighter (hypopigmentation). Hyperpigmentation and Skin Hyperpigmentation in skin is caused by an increase in melanin, the substance in the body that is responsible for color (pigment). Certain conditions, such as pregnancy or Addison's disease (decreased function of the adrenal gland), may cause a greater production of melanin and hyperpigmentation. Exposure to sunlight is a major cause of hyperpigmentaion, and will darken already hyperpigmented areas. Hyperpigmentation can also be caused by various drugs, including some antibiotics , antiarrhythmics, and antimalarial drugs. Melasma An example of hyperpigmentation is melasma (also known as chloasma). This condition is characterized by tan or brown patches, most commonly on the face. Melasma can occur in pregnant women and is often called the "mask of pregnancy;" however, men can also develop this condition. Melasma sometimes goes away after pregnancy. It can also be treated with certain prescription creams (such as hydroquinone ). If you have melasma, try to limit your exposure to daylight. Wear a broad-brimmed hat and use a sunscreen with an SPF of 30 or higher at all times, because sunlight will worsen your condition. Sunscreens containing the physical blockers zinc oxide or titanium dioxide are also helpful in blocking daylight’s UVA rays, which makes hyperpigmentation worse. Consult with your doctor before treating the condition yourself. Hypopigmentation and Skin Hypopigmentation in skin is the result of a reduction in melanin production. Examples of hypopigmentation include: Vitiligo : Vitiligo causes smooth, white patches on the skin. In some people, these patches can appear all over the body. It is an autoimmune disorder in which the pigment-producing cells are damaged. There is no cure for vitiligo, but there are several treatments, including cosmetic cover-ups, corticosteroid creams, or ultraviolet light treatments. Albinism : Albinism is a rare inherited disorder caused by the absence of an enzyme that produces melanin. This results in a complete lack of pigmentation in skin, hair , and eyes . Albinos have an abnormal gene that restricts the body from producing melanin. There is no cure for albinism. People with albinism should use a sunscreen at all times because they are much more likely to get sun damage and skin cancer . This disorder can occur in any race, but is most common among whites. Pigmentation loss as a result of skin damage: If you've had a skin infection, blisters , burns, or other trauma to your skin, you may have a loss of pigmentation in the affected area. The good news with this type of pigment loss is that it's frequently not permanent, but it may take a long time to re-pigment. Cosmetics can be used to cover the area, while the body regenerates the pigment. Continued


Which tissue secretes progesterone during the second half of the menstrual cycle?

You & Your Hormones | Hormones | Progesterone You & Your Hormones   Email article to a friend | Last updated: January 14, 2015 Progesterone is a hormone released by the corpus luteum in the ovary. It plays important roles in the menstrual cycle and in maintaining the early stages of pregnancy. It may also be involved in the growth of certain cancers. What is progesterone? Progesterone belongs to a group of steroid hormones called progestogens . It is mainly secreted by the corpus luteum in the ovary during the second half of the menstrual cycle.  It plays important roles in the menstrual cycle and in maintaining the early stages of pregnancy. During the menstrual cycle, when an egg is released from the ovary at ovulation (approximately day 14), the remnants of the ovarian follicle that enclosed the developing egg form a structure called the corpus luteum. This releases progesterone and, to a lesser extent, oestradiol . The progesterone prepares the body for pregnancy in the event that the released egg is fertilised. If the egg is not fertilised, the corpus luteum breaks down, the production of progesterone falls and a new menstrual cycle begins. If the egg is fertilised, progesterone stimulates the growth of blood vessels that supply the lining of the womb (endometrium) and stimulates glands in the endometrium to secrete nutrients that nourish the early embryo. Progesterone then prepares the tissue lining of the uterus to allow the fertilised egg to implant and helps to maintain the endometrium throughout pregnancy. During the early stages of pregnancy, progesterone is still produced by the corpus luteum and is essential for supporting the pregnancy and establishing the placenta . Once the placenta is established, it then takes over progesterone production at around week 12 of pregnancy. During pregnancy, progesterone plays an important role in the development of the foetus; stimulates the growth of maternal breast tissue; prevents lactation; and strengthens the pelvic wall muscles in preparation for labour . The level of progesterone in the body steadily rises throughout pregnancy until labour occurs and the baby is born. Although the corpus luteum in the ovaries is the major site of progesterone production in humans, progesterone is also produced in smaller quantities by the ovaries themselves, the adrenal glands and, during pregnancy, the placenta. How is progesterone controlled? The formation of the corpus luteum (which produces the majority of progesterone) is triggered by a surge in luteinising hormone production by the anterior pituitary gland . This normally occurs at approximately day 14 of the menstrual cycle and it stimulates the release of an egg from the ovary and the formation of the corpus luteum. The corpus luteum then releases progesterone which prepares the body for pregnancy. If the egg is not fertilised and no embryo is conceived, the corpus luteum breaks down and the production of progesterone decreases. As the lining of the womb is no longer maintained by progesterone from the corpus luteum, it breaks away and menstrual bleeding occurs, marking the start of a new menstrual cycle. However, if the ovulated egg is fertilised and gives rise to an embryo, the cells that surround this early embryo (which are destined to form the placenta) will secrete human chorionic gonadotrophin . This hormone has a very similar chemical structure to luteinising hormone. This means it can bind to and activate the same receptors as luteinising hormone, meaning that the corpus luteum does not break down and instead keeps producing progesterone until the placenta is established.  What happens if I have too much progesterone? There are no known serious medical consequences of having too much progesterone. Levels of progesterone do increase naturally in pregnancy as mentioned above. High levels of progesterone are associated with the condition congenital adrenal hyperplasia . However, the high progesterone levels are a consequence of and not a cause of this condition. Also, high levels of progesterone are associated with an


Which gland secretes the corticosteroids?

Adrenal Glands | Johns Hopkins Medicine Health Library Adrenal Glands: What You Need to Know Adrenal glands, also known as suprarenal glands, are small, triangular-shaped glands located on top of both kidneys. Adrenal glands produce hormones that help regulate your metabolism, immune system, blood pressure, response to stress and other essential functions. Adrenal glands are composed of two parts — the cortex and the medulla — which are each responsible for producing different hormones. When adrenal glands don’t produce enough hormones, this can lead to adrenal insufficiency (Addison’s disease). Adrenal glands may develop nodules that can be benign or malignant. These nodules may produce excessive amounts of certain hormones leading to various health issues. Anatomy of the Adrenal Glands An adrenal gland is made of two main parts: The adrenal cortex is the outer region and also the largest part of an adrenal gland. It is divided into three separate zones: zona glomerulosa, zona fasciculata and zona reticularis. Each zone is responsible for producing specific hormones. The adrenal medulla is located inside the adrenal cortex in the center of an adrenal gland. It produces several “stress hormones,” including adrenaline. The adrenal cortex and adrenal medulla are enveloped in an adipose capsule that forms a protective layer around an adrenal gland. Hormones of the Adrenal Glands The role of the adrenal glands in your body is to release certain hormones directly into the bloodstream. Many of these hormones have to do with how the body responds to stress, and some are vital to existence. Both parts of the adrenal glands — the adrenal cortex and the adrenal medulla — perform distinct and separate functions. Each zone of the adrenal cortex secretes a specific hormone. The key hormones produced by the adrenal cortex include: Cortisol Cortisol is a glucocorticoid hormone produced by the zona fasciculata that plays several important roles in the body. It helps control the body’s use of fats, proteins and carbohydrates; suppresses inflammation; regulates blood pressure; increases blood sugar; and can also decrease bone formation. This hormone also controls the sleep/wake cycle. It is released during times of stress to help your body get an energy boost and better handle an emergency situation. How Adrenal Glands Work to Produce Cortisol Adrenal glands produce hormones in response to signals from the hypothalamus and the pituitary gland in the brain. For example, for the adrenal gland to produce cortisol: The hypothalamus produces corticotropin-releasing hormone (CRH) that stimulates the pituitary gland to secrete adrenocorticotropin hormone (ACTH). The ACTH then stimulates the adrenal glands to make and release cortisol hormones into the blood. Normally, both the hypothalamus and the pituitary gland can sense whether the blood has the right amount of cortisol in it. If there is too much or too little cortisol, these glands respectively change the amount of CRH and ACTH that gets released. Excess cortisol production can occur from nodules in the adrenal gland or excess production of ACTH from a tumor in the pituitary gland or other source. Aldosterone This mineralocorticoid hormone produced by the zona glomerulosa plays a central role in regulating blood pressure and certain electrolytes (sodium and potassium). Aldosterone sends signals to the kidneys, resulting in the kidneys absorbing more sodium into the bloodstream and releasing potassium into the urine. This means that aldosterone also helps regulate the blood pH by controlling the levels of electrolytes in the blood. DHEA and Androgenic Steroids These hormones produced by the zona reticularis are weak male hormones. They are precursor hormones that are converted in the ovaries into female hormones (estrogens) and in the testes into male hormones (androgens). However, estrogens and androgens are produced in much larger amounts by the ovaries and testes. Epinephrine (Adrenaline) and Norepinephrine (Noradrenaline) The adrenal medulla, the inner part of an adrenal gland, controls


What are the natural pain-killing substances produced in the brain and pituitary gland?

Endorphins | definition of endorphins by Medical dictionary Endorphins | definition of endorphins by Medical dictionary http://medical-dictionary.thefreedictionary.com/endorphins Related to endorphins: dopamine , serotonin en·dor·phins (en-dōr'finz, en'dōr-finz), Opioid peptides originally isolated from the brain but now found in many parts of the body; in the nervous system, endorphins bind to the same receptors that bind exogenous opiates. A variety of endorphins (for example, α, β, and γ) that vary not only in their physical and chemical properties but also in physiologic action have been isolated. [fr. endogenous morphine] endorphins A number of morphine-like peptide substances naturally produced in the body and for which morphine receptors exist in the brain. Many of these active substances have been found, all with the same opioid core of five amino acids. They are neurotransmitters and have a wide range of functions. They help to regulate heart action, general hormone function, the mechanisms of shock from blood loss and the perception of pain, and are probably involved in controlling mood, emotion and motivation. They are thought to be produced under various circumstances in which acute relief of pain or mental distress is required. At least some of the endorphins are produced by the PITUITARY gland as part of the precursor of the ACTH molecule. Endorphins are fragments cleaved from the beta-lipotropin component of proopiomelanocortin ( POMC ). The term derives from the phrase ‘endogenous morphines’. Endorphins Pain-killing substances produced in the human body and released by stress or trauma. Some researchers think that people who mutilate themselves are trying to trigger the release of endorphins. Mentioned in: Methadone , Pet Therapy , Self-Mutilation , Stress Reduction endorphins group of opioid peptides made in nerve cells in the brain and released from their axons as neurotransmitters or neurohormones, which bind to and activate opioid receptors of other cells (where opioid drugs also act). The first to be identified in brain tissue (1970s) were named enkephalins; many more were later identified. They are released in strenuous exercise and in stressful or painful situations. Subgroups have varied and widespread actions, diminishing the sensation of pain, inducing euphoria (e.g. 'runner's high') and interacting with the immune system. endorphins naturally occurring opioids liberated within brain, spinal cord and peripheral tissues during exercise; interact with tissue opiate receptors, inducing pain reduction, euphoria and general well-being endorphins, n.pl polypeptides produced in the body that bind the neuroreceptors in brain and act on the central and peripheral nervous system to alleviate pain. en·dor·phins (en-dōr'finz)


What hormone was discovered by John Jacob Abel?

The Sucrose Molecule The       Epinephrine Molecule using Jmol -- For       3D Structures Epinephrine or adrenaline (European Pharmacopoeia        and BAN) , sometimes spelled "epinephrin" or "adrenalin" respectively,        is a hormone when carried in the blood and a neurotransmitter        when it is released across a neuronal synapse. It is a catecholamine,        a sympathomimetic monoamine derived from the amino acids phenylalanine        and tyrosine. The Latin roots ad-+renes and        the Greek roots epi-+nephros both literally        mean "on/to the kidney" (referring to the adrenal gland, which        sits atop the kidneys and secretes epinephrine). Epinephrine        is sometimes shortened to epi or to EP in medical        jargon. History In May 1886, William Bates reported the discovery of a         substance produced by the adrenal gland in the New York          Medical Journal. Epinephrine was isolated and identified         in 1895 by Napoleon Cybulski, a Polish physiologist. The         discovery was repeated in 1897 by John Jacob Abel.[1]. Jokichi Takamine, a Japanese chemist, independently         discovered the same hormone in 1900.[2][3]In 1901 he isolated and purified the hormone         adrenaline from cow glands.It was first artificially synthesized         in 1904 by Friedrich Stolz. Triggers Epinephrine is a "fight or flight" hormone, and plays a         central role in the short-term stress reaction. It is released         from the adrenal glands when danger threatens or in an emergency.         Such triggers may be threatening, exciting, or environmental         stressor conditions such as high noise levels or bright         light (see Fight-or-flight response). An example of noise-induced trigger of epinephrine release         is tinnitus. The fight-or-flight response caused by tinnitus         is a contributor to physical stress seen in tinnitus-patients,[4] exacerbating the case. Actions in the body When secreted into the bloodstream, it rapidly prepares         the body for action in emergency situations. The hormone         boosts the supply of oxygen and glucose to the brain and         muscles, while suppressing other non-emergency bodily processes         (digestion in particular). It increases heart rate and stroke volume, dilates the         pupils, and constricts arterioles in the skin and gut while dilating arterioles in skeletal muscles. It elevates the         blood sugar level by increasing catalysis of glycogen to         glucose in the liver, and at the same time begins the breakdown         of lipids in fat cells. Like some other stress hormones,         epinephrine has a suppressive effect on the immune system.[5] Although epinephrine does not have any psychoactive effects,         stress or arousal also releases norepinephrine in the brain.         Norepinephrine has similar actions in the body, but is also         psychoactive. The type of action in various cell types depends on their         expression of adrenergic receptors. Adrenergic receptors Epinephrine's actions are mediated through adrenergic          receptors: It binds to Î±1 receptors of liver          cells, which activate inositol-phospholipid signaling          pathway, signaling the phosphorylation of glycogen synthase          and glycogen phosphorylase (inactivating and activating          them, respectively), leading to breakdown of glycogen          (glycogenolysis) so as to release glucose to the bloodstream. Epinephrine also activates Î²-adrenergic receptors of the liver and muscle cells, thereby activating the          adenylate cyclase signaling pathway, which will in turn          increa


What is the substance produced by hard exercise and oxygen debt, causing stiffness in the muscles?

Oxygen Debt & Recovery | Energy Systems | Anatomy & Physiology Oxygen Debt & Recovery Oxygen Debt & Recovery What is it all about then? When you have a short intense burst of exercise such as sprinting you generate energy for this anaerobically or without oxygen. When you stop exercising you are still breathing heavily. This is your body taking in extra oxygen to 'repay' the oxygen debt. Well, that is the simple solution but there is a little more to it if you want to look a bit deeper. True, your body has worked anaerobically and will have produced energy without some of the oxygen it would normally have used performing low intensity exercise such as slow steady running. The difference between the oxygen the body required and what it actually managed to take in during the sudden sprint is called oxygen deficit. When you stop sprinting and start to recover you will actually need more oxygen to recover than your body would have liked to use had enough been available. This is called Excess Post Exercise Oxygen Consumption. So why does it take more oxygen to recover then? You needed to replace the oxygen the body needed but couldnt get (oxygen deficit). Breathing rate and heart rate are elevated (to remove CO2) and this needs more oxygen. Body temperature and metabolic rate is increased and this needs more oxygen. Adrenaline and Noradrenaline are increased which increases oxygen consumption.   So after exercise there are other factors causing an increase in oxygen needs as well as repaying the lack of oxygen during exercise. The chart below is often seen and shows how the amount of oxygen used by the body changes over time. At the beginning the body works anaerobically leaving an oxygen deficit. Over time the oxygen consumption levels out to a steady state. After exercise the oxygen is pain back (oxygen debt). Notice the area of oxygen debt is greater than the area of oxygen deficit for the reasons stated above. What has Lactic Acid got to do with it? Lactic acid is a by product of exercising without using oxygen (anaerobially). It is essential this is removed but it is not necessarily a waste product. It is recycled into other useful chemicals: During prolonged intensive exercise (e.g. 800m race) the heart may get half its energy from lactic acid. It is converted back to pyruvic acid and used as energy by the heart and other muscles. It is thought that 70% of lactic acid produced is oxidised, 20% is converted to glucose (energy) in the liver. 10% is converted to protein. How long does it take to remove lactic acid? About 1 hour if cooling down with gentle exercise. It can take 2 hours or more if you dont warm down with gentle exercise. More Anatomy & Physiology


Where would you find the carotid arteries?

An Overview of Carotid Artery Disease Sedentary lifestyle Family history of atherosclerosis, either coronary artery disease or carotid artery disease Men younger than age 75 have a greater risk than women in the same age group. Women have a greater risk than men older than age 75. People who have coronary artery disease have an increased risk of developing carotid artery disease. Typically, the carotid arteries become diseased a few years later than the coronary arteries. Continued What Are the Symptoms of Carotid Artery Disease? You may not have any symptoms of carotid artery disease. Plaque builds up in the carotid arteries over time with no warning signs until you have a transient ischemic attack (TIA) or a stroke. Signs of a stroke may include: Sudden loss of vision , blurred vision , or difficulty in seeing out of one or both eyes Weakness , tingling, or numbness on one side of the face, one side of the body, or in one arm or leg Sudden difficulty in walking, loss of balance, lack of coordination Sudden dizziness and/or confusion   How Is Carotid Artery Disease Diagnosed? There are often no symptoms of carotid artery disease until you have a TIA or stroke. That’s why it’s important to see your doctor regularly for physical exams. Your doctor may listen to the arteries in your neck with a stethoscope. If an abnormal sound, called a bruit, is heard over an artery, it may reflect turbulent blood flow. That could indicate carotid artery disease. Listening for a bruit in the neck is a simple, safe, and inexpensive way to screen for stenosis (narrowing) of the carotid artery, although it may not detect all blockages. Some experts believe that bruits may be better predictors of atherosclerotic disease rather than risk of stroke. Be sure to let your doctor know if you have had any symptoms, such as those listed above. Continued Your doctor may also use a test to diagnose carotid artery disease. Possible tests include the following: Carotid ultrasound (standard or Doppler). This noninvasive, painless screening test uses high-frequency sound waves to view the carotid arteries. It looks for plaques and blood clots and determines whether the arteries are narrowed or blocked. A Doppler ultrasound shows the movement of blood through the blood vessels. Ultrasound imaging does not use X-rays. Magnetic resonance angiography (MRA). This imaging technique uses a powerful magnet to gather accurate information about the brain and arteries. Then a computer uses this information to generate high-resolution images. An MRA can often detect even small strokes in the brain. Computerized tomography angiography (CTA). More detailed than an X-ray, a CT uses X-rays and computer technology to produce cross-sectional images of the carotid arteries. Images of the brain can be collected as well. With this imaging test, the scan may reveal areas of damage on the brain. The CT scan uses a low level of radiation . Cerebral angiography ( carotid angiogram ). This procedure is considered the gold standard for imaging the carotid arteries. It is an invasive procedure that lets a doctor see blood flow through the carotid arteries in real time. Cerebral angiography allows the doctor to see narrowing or blockages on a live X-ray screen as contrast dye is injected in the carotid arteries. This procedure provides the best information. It does carry a small risk of serious complications.   Continued Which Drugs Can Reduce the Risk of Stroke? Your doctor may recommend antiplatelet medications such as aspirin and clopidogrel (Plavix) to decrease the risk of stroke caused by blood clots. Your doctor may also prescribe medications to lower cholesterol and blood pressure . In some cases, warfarin ( Coumadin ), a blood thinner , may be prescribed.   What Medical Procedures Treat Carotid Artery Disease? If there is severe narrowing or blockage in the carotid artery, a procedure can be done to open the artery. This will increase blood flow to the brain to prevent future stroke. Your doctor may suggest either of the following procedures: Carotid endarterectomy (CEA). Thi


Protein is important for beautiful skin, hair and nails - Nutrition Express Articles Protein is important for beautiful skin, hair and nails Learn why protein plays such a major role in your overall health by Judy Lindberg McFarland When you look in the mirror, what do you see? Do you see soft, supple, radiant, glowing, blemish-free skin? Or do you see age spots and new wrinkles? The skin is the first "aging" sign we tend to see in ourselves. We all want to find ways to keep our skin beautiful, soft, and, we hope, wrinkle free. We will each get some wrinkles, but nobody wants them prematurely! My mother, Gladys Lindberg, had the most beautiful skin for her age of any woman I have ever seen. She far surpassed the "beauty experts" and "movie stars" in her beauty and grace. At age 85 she had a clear, peachy complexion and was virtually wrinkle free! She had no patchy "age" spots or blemished skin. She never smoked and avoided the sun whenever possible. This was natural beauty. Mother started her quest for health when she was 43 years old. She said her skin was blotchy and never radiant, but her program drastically changed the quality of her skin. Important advice for skin health A woman recently came into our store looking for a "magic formula" for her deeply wrinkled skin. She was only in her mid-40s, but said her skin had changed drastically over the past months. Being quite disturbed about the situation, she came to me wanting "that miracle cream." I talked to her for a few minutes and discovered that she had been on a severe reducing diet for several months. She had followed a diet low in protein, and over the course of those months had lost her skin tone. It had started to sag and wrinkle way beyond what would be normal for her chronological age. Most women want to be slim, but if you saw her, I'm sure you would agree, "not at that price!" Here are some things I told her that are important for healthy skin regardless of whether you're trying to lose weight or not. Collagen - the skin's "cement" Elastic skin is a sign that a person has ample collagen, the strong cement-like material that binds together the cells of your body. Collagen is a structural tissue and it is replaced very slowly. It is made of fibrous protein. In fact, collagen comprises 30 percent of the total body protein. Its strong white fibers, stronger than steel wire of the same size, and yellow elastic networks, called elastin, form the connective tissue that holds our body together. Collagen strengthens the skin, blood vessels, bones, and teeth. It is the intracellular cement that holds together the cells in various organs and tissues. Collagen is one of the most valuable proteins in the human body. A person who has been sick, or who has been on an extremely low-protein diet, very often sees the muscles in his or her arms and legs begin to sag, which is a sign that they have probably lost collagen. Start with protein The building blocks of protein are amino acids. When protein is eaten, your digestive processes break it down into amino acids, which pass into the blood and are carried throughout the body. Your cells can then select the amino acids they need for the construction of new body tissue, antibodies, hormones, enzymes, and blood cells. There are 22 different amino acids, each of which has its own characteristics, and are like the letters of the alphabet. The eight essential amino acids are like the vowels. Just as you cannot make words without vowels, so you cannot build proteins without these essential amino acids. Protein is not one substance, but literally tens of thousands of different substances. The essential amino acids must be consumed in the diet because the body does not make them. The complete proteins that contain the eight essential amino acids come from meat, poultry, fish, eggs, milk -- all dairy, cheese and soy. They are basically anything that comes from the animal. Nuts and legumes (peas and beans) contain some but not all of the essential amino acids; these are known as incomplete proteins. In various combinations, all of the


Which gas released by car exhausts, stops the blood hemoglobin from working correctly?

What you need to know about carbon monoxide What you need to know about the leading cause of poisoning deaths in America Carbon Monoxide The following text is from the booklet What you need to know about the leading cause of poisoning deaths in America: Carbon monoxide (1996), prepared as a public service by First Alert in cooperation with the Cooperative State Research, Education, and Extension Service (CSREES) of the U.S. Department of Agriculture. If you have questions about carbon monoxide, contact your local gas utility, a qualified heating contractor, or the Extension Services office listed in the white pages of your phone book. What is carbon monoxide and who is at risk? Carbon monoxide (CO) is a colorless, odorless deadly gas. Because you can't see, taste, or smell it, carbon monoxide can kill you before you know it's there. Everyone is at risk for carbon monoxide poisoning. Experts believe, however, that individuals with greater oxygen requirements such as unborn babies, infants, children, senior citizens, and people with coronary or respiratory problems are at greater risk.   Why is carbon monoxide so dangerous? The great danger of carbon monoxide is its attraction to hemoglobin in the bloodstream. When breathed in, carbon monoxide replaces the oxygen which cells need to function. When CO is present in the air, it rapidly accumulates in the blood, causing symptoms similar to the flu, such as headaches, fatigue, nausea, dizzy spells, confusion, and irritability. As levels increase, vomiting, loss of consciousness, and eventually brain damage or death can result.   Where does carbon monoxide come from? Carbon monoxide is a by-product of combustion, present whenever fuel is burned. It is produced by common home appliances, such as gas or oil furnaces, gas refrigerators, gas clothes dryers, gas ranges, gas water heaters or space heaters, fireplaces, charcoal grills, and wood burning stoves. Fumes from automobiles and gas-powered lawn mowers also contain carbon monoxide and can enter a home through walls or doorways if an engine is left running in an attached garage. All of these sources can contribute to a CO problem in the home. If a home is vented properly and is free from appliance malfunctions, air pressure fluctuations or airway blockages, carbon monoxide will most likely be safely vented to the outside. But in today's "energy efficient" homes this is frequently not the case. Tightly constructed/sealed homes can trap CO-polluted air in a home year-round. Furnace heat exchangers can crack, vents can become blocked, inadequate air supply for combustion appliances can cause conditions known as backdrafting or reverse stacking, which force contaminated air back into the home. Exhaust fans on range hoods, clothes dryers and bathroom fans can also pull combustion products into the home.   How can I protect myself and my family from carbon monoxide poisoning? The Consumer Product Safety Commission (CPSC) recommends installing at least one carbon monoxide detector per household, near the sleeping area. Additional detectors on every level of a home and in every bedroom provide extra protection. Choose an Underwriters Laboratories Inc. (UL) listed detector that sounds an audible alarm. You can choose a model that is wired to your home's electrical system, a model which plugs into a standard electrical outlet, or a battery-operated model. Battery-operated carbon monoxide detectors continue to protect even in the event of a power outage. Hardwired AC models, although more costly and difficult to install, reduce the expense of battery replacement but do not offer protection during power outages. Hardwired AC models with battery back-up offer double protection. Gas appliances should be serviced yearly by a qualified service technician. Stove burners should be cleaned and adjusted to minimize the amount of carbon monoxide produced. Before making changes to a house that might affect the ventilation of fuel-burning appliances, contact your heating contractor. When replacing heating appliances, purchase appliances designed to r


What device is added to a car's exhaust system to reduce pollution?

Fuel + Air => Hydrocarbons + Nitrogen Oxides + Carbon Dioxide + Carbon Monoxide + Sulphur Dioxide+ water Hydrocarbon emissions are fragments of fuel molecules, only partially burned. See Toxicity Hydrocarbons in exhaust. Hydrocarbons react in the presence of nitrogen oxides and sunlight to form ground-level ozone, a major component of smog. Ozone irritates the eyes, nose, throat and damages the lungs. A number of exhaust hydrocarbons are also toxic, some with the potential to cause cancer. Nitrogen Oxides Under high pressure and temperature conditions in an engine, nitrogen and oxygen atoms react to form nitrogen oxides. Nitrogen dioxide, NO2, is a brownish toxic gas, an important air pollutant. The air of cities with high levels of car ownership has a distinctly brown tinge. NO2 combines with water in the air to form nitric acid - acid rain. A complex chemistry involves NO2 combining with hydrocarbons to form the photochemical smog that poisons city dwellers. Sunlight converts unburned hydrocarbons to more reactive molecules such as aldehydes and ketones which generate peroxyacyl radicals that react with NO2 forming peroxyacyl nitrates(PANs). Catalytic converters in car exhaust systems reduce air pollution in the best case by breaking down NO2 and N20 to nitrogen (N2) and oxygen(O2). Nitrous oxide (N2O) also known as "laughing gas" has medical uses, but is a pollutant in the air. N2O, for example gives rise to nitric oxide (NO) which reacts with  and depletes ozone. N2O is a combustion product but also originates from forest fires, lightning storms nitrogen-based fertilizers and manure from farm animals. According to the US EPA industrial sources make up only about 20% of all anthropogenic sources of N2O, including the burning of fossil fuel in internal combustion engines. Indoor gas burning appliances generate N2O.  It is also a major greenhouse gas and air pollutant with about 300 times more global-warming potential than carbon dioxide. Carbon Monoxide Carbon monoxide (CO) is a colorless, odorless, poisonous gas, a product of incomplete burning of hydrocarbon-based fuels. Carbon monoxide consists of a single carbon atom and a single oxygen atom linked together (CO), the product of incomplete combustion of fuel. Most CO is produced when air-to-fuel ratios are too low in the engine during vehicle starting, when cars are not tuned properly, and at higher altitudes, where thin air reduces the amount of oxygen available for combustion. Two-thirds of the carbon monoxide emissions come from transportation sources, with the largest contribution coming from cars. In urban areas, the passenger vehicle contribution to carbon monoxide pollution can exceed 90%.Read more about Carbon Monoxide Carbon Dioxide U.S. Environmental Protection Agency (EPA) originally viewed carbon dioxide as a product of "perfect" combustion, but now views CO2 as a pollution concern. Carbon dioxide is a greenhouse gas that traps the earth's heat and contributes to Climate Change Particle Pollution and Human Disease The U.S. Environmental Protection Agency (EPA) defines fine-particle air pollution, PM10, particulate matter 10 micrometers or less in diameter. Suspended particles in the air create aerosols that are important to the behavior of whole atmosphere and play a role in determining human disease. Natural sources of atmospheric particles are volcanoes, dust storms, spontaneous forest fires, tornadoes and hurricanes. Clouds are a product of aerosols that seed the formation of water droplets. Human air pollution now dominates aerosol production over cities with negative health effects. Thick aerosols are obvious as haze and contain a complex system of particles with adherent toxic gases such as sulphur dioxide. Air pollution is associated with increased hospital admissions for cardiovascular diseases with increases in acute morbidity and mortality. D'Ippoliti et al studied 6531 patients in Rome who were hospitalized for acute myocardial infarction from January 1995 to June 1997. Air pollution data were


Why Odd Egg-Laying Mammals Still Exist Why Odd Egg-Laying Mammals Still Exist By Charles Q. Choi, Live Science Contributor | September 21, 2009 11:06am ET MORE The platypus, found only in Australia is one of the five mammal species of that lay eggs instead of giving birth to live young. The other egg-laying mammals are four species of echidna. Credit: Gerry Pearce, australian-wildlife.com. The reason that odd, egg-laying mammals still exist today may be because their ancestors took to the water, scientists now suggest. The egg-laying mammals — the monotremes, including the platypus and spiny anteaters — are eccentric relatives to the rest of mammals, which bear live young. In addition to laying eggs, other quirks make them seem more like reptiles than our kin. They have a reptilian gait with legs on the sides rather than underneath the body, for instance, and a single duct for urine, feces and sex instead of multiple openings. These oddballs are often considered primitive "living fossils" that shed light on what our distant ancestors might have looked like. Australian invasion Long ago, monotremes and their close relatives were the dominant mammals in the whole of Australia. Now only two kinds of monotremes are left on the planet — the duck-billed platypuses and the four species of echidnas, or spiny anteaters. Like all mammals, they possess hair, milk, sweat glands, three middle ear bones and a brain region known as the neocortex. The monotremes were almost totally swept aside when their pouch-bearing marsupial cousins — modern examples of which include the kangaroos — invaded Australia 71 million to 54 million years ago. Marsupials appear to have a number of advantages over monotremes — their bodies seem more efficient at locomotion, and the fact that they give birth to live offspring could provide better care of young. Moreover, before the marsupials reached Australia, they had migrated from Asia to the Americas to Antarctica. The struggle marsupials presumably had with all the animals on these continents during this journey might have primed them for competition, "while the Australian mammals [including monotremes] that went extinct upon the arrival of marsupials had for the most part been isolated in Australia for a very long time," explained researcher Matthew Phillips, an evolutionary biologist at the Australian National University in Canberra. All these strengths help explain why marsupials triumphed in Australia. The mystery then is why any monotremes survived. Swim for it! Now Phillips and his colleagues suggest that platypuses and echidnas lived on because their ancestors sought refuge where marsupials could not follow — the water. Platypuses are amphibious creatures, while echidnas — the anteaters — are terrestrial. However, new genetic evidence and comparisons with fossil monotremes suggests that echidnas only diverged from platypuses 19 to 48 million years ago. This means echidnas recently had semi-aquatic predecessors and only later recolonized the land. A number of aspects of echidna biology are consistent with an amphibious platypus-like ancestor — a streamlined body, rearward-jutting hind limbs that could act as rudders, and the contours of a duck-like bill during embryonic development. "Platypus-like fossils are known from at least 61 million years ago. It was thought that the much shorter fossil record for echidnas, from about 13 million years ago, was just due to the patchy nature of the fossil record," Phillips said. Their new findings suggest "the lack of early echidna fossils was in fact because they simply had not evolved yet." The researchers conjecture that marsupials could not afford a substantial invasion of aquatic environments because when they are born, they need to suckle milk constantly for weeks; newborn marsupials could drown if their mothers ever had to venture into the water. Evidence fits These findings remove an apparent contradiction between fossil data and DNA evidence, said Zhe-Xi Luo, curator of vertebrate paleontology at the Carnegie Museum of Natural History in Pittsburgh. Ev


What is the term for something that will break down naturally?

Terms to Know Biodegradable Definition A “biodegradable” product has the ability to break down, safely and   relatively quickly, by biological means, into the raw materials of   nature and disappear into the environment.  These products can be solids biodegrading into the soil   (which we also refer to as compostable), or liquids biodegrading   into water.  Biodegradable plastic is intended to break up when exposed to   microorganisms (a natural ingredient such as cornstarch or vegetable   oil is added to achieve this result). Sustainable disposal of any product requires that its wastes return   to the earth and are able to biodegrade.  Nature biodegrades everything it makes back into basic   building blocks, so that new living things can be made from the old.  Every resource made by nature returns to nature - plants and   animals biodegrade, even raw crude oil will degrade when exposed to   water, air and the necessary salts.  Nature has perfected this system - we just need to learn how   to participate in it. By the time many resources are turned into products, however, they   have been altered by industry in such a way that they are   unrecognizable to the microorganisms and enzymes that return natural   materials to their basic building blocks.  Crude oil, for example, will biodegrade in its natural state,   but once it is turned into plastic, it becomes an unsustainable   pollution problem.  Instead of returning to the cycle of life, these products simply   pollute and litter our land, air and water. Of all the environmental buzzwords “biodegradable” has perhaps been   the most misused and the most difficult to understand.  Because in the past there have been no guidelines or   regulations, many products have called themselves biodegradable   without any real justification.  Unfortunately, the word biodegradable has frequently been   applied to products that generally aren’t (such as detergents or   plastics) and almost never used for products that really are (such   as soap or paper). A leaf is a perfect example of a biodegradable product -- it is made   in the spring, used by the plant for photosynthesis in the summer,   drops to the ground in autumn and assimilated into the soil to   nourish the plant for the next season.  The basic concept seems straightforward enough, however,   there are several factors to consider in determining the   biodegradability of a product or material. The first is the question of the inherent biodegradability of the   material.  Any material   that comes from nature will return to nature as long as it is still   in a relatively natural form.  Therefore, any plant-based, animal-based or natural   mineral-based product has the capability to biodegrade, but products   made from man-made petrochemical compounds generally do not.  When a manmade compound is formulated in a laboratory,   combinations of elements are made that do not exist in nature and   there are no corresponding microorganisms to break them down. The next issue is how long it takes for the material to actually   break down.  In nature,   different materials biodegrade at different rates.  A leaf takes approximately a year to become part of the   forest floor.  An iron   shovel, on the other hand, can take years to rust away to nothing   and a large tree can take decades to completely break down.  Common sense tells us that any material will ultimately   biodegrade, even if it takes centuries. So what is the proper rate for a material to be biodegradable?  It really depends on the material itself.  The leaf example suggests that the proper rate is that which   is appropriate to the ecosystem. A liquid going into a waterway   should biodegrade fairly quickly, whereas there’s no harm done if it   takes a while for a newspaper to break down.  Plastics, on the other hand, will not biodegrade in anyone’s   lifetime and certainly will never break back down into the petroleum   from which it is made. And then there is the question of what


Which is the most common gas in the atmosphere?

Earth's Atmosphere | UCAR Center for Science Education Earth's Atmosphere The layered structure of Earth's atmosphere is visible in this sunset view from the International Space Station. Credit: Image Science & Analysis Laboratory, NASA Johnson Space Center Earth's atmosphere is a mixture of gases that surrounds our home planet. Besides providing us with something to breathe, the atmosphere helps make life on Earth possible in several ways. It shields us from most of the harmful ultraviolet (UV) radiation coming from the Sun, warms the surface of our planet by about 33° C (59° F) via the greenhouse effect, and largely prevents extreme differences between daytime and nighttime temperatures. The atmosphere is a mixture of many different gases. Nitrogen and oxygen are by far the most common; dry air is composed of about 78% nitrogen (N2) and about 21% oxygen (O2). Argon, carbon dioxide (CO2) , and many other gases are also present in much lower amounts; each makes up less than 1% of the atmosphere's mixture of gases. The atmosphere also includes water vapor. The amount of water vapor present varies a lot, but on average is around 1%. There are also many small particles - solids and liquids - "floating" in the atmosphere. These particles, which scientists call "aerosols", include dust, spores and pollen, salt from sea spray, volcanic ash, smoke, and more. The atmosphere grows thinner (less dense and lower in pressure) as one moves upward from Earth's surface. It gradually gives way to the vacuum of outer space. There is no precise "top" of the atmosphere. Air becomes so thin at altitudes between 100 and 120 km (62-75 miles) up that for many purposes that range of heights can be considered the boundary between the atmosphere and space. However, there are very thin but measurable traces of atmospheric gases hundreds of kilometers/miles above Earth's surface. There are several different regions or layers in the atmosphere. Each has characteristic temperatures, pressures, and phenomena. We live in the troposphere , the lowest layer, where most clouds are found and almost all weather occurs. Some jet aircraft fly in the next higher layer, the stratosphere , which contains the jet streams and the ozone layer. Higher still are the mesosphere , thermosphere and exosphere . © 2011 UCAR


Which fuel is formed by the fossilization of plants?

DOE - Fossil Energy: How Fossil Fuels Were Formed You are here:  Educational Activities  >  Energy Lessons  >  Coal-Introduction  > Fossil Fuel Formation How Fossil Fuels were Formed Contrary to what many people believe, fossil fuels are not the remains of dead dinosaurs. In fact, most of the fossil fuels we find today were formed millions of years before the first dinosaurs.   Formation of Coal   Fossil fuels were formed from plants and animals that lived 300 million years ago in primordial swamps and oceans (top). Over time the plants and animals died and decomposed under tons of rock and ancient seas (middle). Eventually, many of the seas receded and left dry land with fossil fuels like coal buried underneath it (bottom). Ten feet of prehistoric plant debris was needed to make one foot of coal.   Fossil fuels, however, were once alive! They were formed from prehistoric plants and animals that lived hundreds of millions of years ago. Think about what the Earth must have looked like 300 million years or so ago. The land masses we live on today were just forming. There were swamps and bogs everywhere. The climate was warmer. Ancient trees and plants grew everywhere. Strange looking animals walked on the land, and just as weird looking fish swam in the rivers and seas. Tiny one-celled organisms called protoplankton floated in the ocean. When these ancient living things died, they decomposed and became buried under layers and layers of mud, rock, and sand. Eventually, hundreds and sometimes thousands of feet of earth covered them. In some areas, the decomposing materials were covered by ancient seas, then the seas dried up and receded. During the millions of years that passed, the dead plants and animals slowly decomposed into organic materials and formed fossil fuels. Different types of fossil fuels were formed depending on what combination of animal and plant debris was present, how long the material was buried, and what conditions of temperature and pressure existed when they were decomposing. For example, oil and natural gas were created from organisms that lived in the water and were buried under ocean or river sediments. Long after the great prehistoric seas and rivers vanished, heat, pressure and bacteria combined to compress and "cook" the organic material under layers of silt. In most areas, a thick liquid called oil formed first, but in deeper, hot regions underground, the cooking process continued until natural gas was formed. Over time, some of this oil and natural gas began working its way upward through the earth's crust until they ran into rock formations called "caprocks" that are dense enough to prevent them from seeping to the surface. It is from under these caprocks that most oil and natural gas is produced today. The same types of forces also created coal, but there are a few differences. Coal formed from the dead remains of trees, ferns and other plants that lived 300 to 400 million years ago. In some areas, such as portions of what-is-now the eastern United States, coal was formed from swamps covered by sea water. The sea water contained a large amount of sulfur, and as the seas dried up, the sulfur was left behind in the coal. Today, scientists are working on ways to take the sulfur out of coal because when coal burns, the sulfur can become an air pollutant. (To find out about these methods, see the section " Cleaning Up Coal .") Some coal deposits, however, were formed from freshwater swamps which had very little sulfur in them. These coal deposits, located largely in the western part of the United States, have much less sulfur in them.   All of these fossil fuels have played important roles in providing the energy that every man, woman, and child in the the United States uses. With better technology for finding and using fossil fuels, each can play an equally important role in the future. To read more about these fuels ï¿½ both past and present ï¿½ click on:


Tides, and the pull of the moon and sun | Earth | EarthSky Tides, and the pull of the moon and sun By Deborah Byrd in Earth | April 7, 2016 The sun, the moon, the shape of a beach and larger coastline, the angle of a seabed leading up to land, and the prevailing ocean currents and winds all affect the height of the tides. This beautiful image is from EarthSky Facebook friend John Lloyd Griffith We all know the moon is primarily responsible for the rising and falling of ocean tides. In most places, but not everywhere, there are two high tides and two low tides a day. For any particular spot on Earth’s surface, the height of the tides and their fluctuation in time depends not only on the moon, but also on the sun – and also on the shape of the specific beach, the larger coastline, the angle of the seabed leading up to land, and the prevailing ocean currents and winds. The difference in height between high and low waters varies as the moon waxes and wanes from new to full and back to new again. The larger tides are called spring tides (nothing to do with season of spring). The smaller tides are called neap tides. Click the links below to learn more about the tides. Why are there two high tides and two low tides each day? Around each new moon and full moon – when the sun, Earth, and moon are located more or less on a line in space – the range between high and low tides is greatest. These are called spring tides. Image via physicalgeography.net What are spring tides? Around each new moon and full moon, the sun, Earth, and moon arrange themselves more or less along a line in space. Then the pull on the tides increases, because the gravity of the sun reinforces the moon’s gravity. In fact, the height of the average solar tide is about 50% the average lunar tide. Thus, at new moon or full moon, the tide’s range is at its maximum. This is the spring tide: the highest (and lowest) tide. Spring tides are not named for the season. This is spring in the sense of jump, burst forth, rise. So spring tides bring the most extreme high and low tides every month, and they happen around full and new moon. What are perigean spring tides? When the new moon or full moon closely aligns with perigee – closest point to Earth in the moon’s orbit – then we have an extra-large perigean spring tides . For example, in the year 2016, the April 7 new moon will closely align with perigee and the November 14 full moon will closely coincide with perigee, to bring forth perigean spring tides. When is the next supermoon? It’s when a spring tide coincides with a time of heavy winds and rain – flooding due to a weather extreme – that the most extreme flooding occurs. Around each first quarter moon and last quarter moon – when the sun and moon are at a right angle to Earth – the range between high and low tides is least. These are called neap tides. Image via physicalgeography.net What are neap tides? These sorts of tides occur halfway between each new and full moon – at the first quarter and last quarter moon phase – when the sun and moon are at right angles as seen from Earth. Then the sun’s gravity is working against the gravity of the moon, as the moon pulls on the sea. This is the neap tide: the tide’s range is at its minimum. Neap tides happen approximately twice a month, once around first quarter moon and once around last quarter moon. There’s about a seven-day interval between spring tides and neap tides. Earth has two tidal bulges, one of the side of Earth nearest the moon (where the moon’s gravity pulls hardest), and the other on the side of Earth farthest from the moon (where the moon’s gravity pulls least). Why are there two high tides and two low tides each day? If the moon is primarily responsible for the tides, why are there two high tides and two low tides each day in most places, for example, the U.S. eastern seaboard? It seems as if there should just be one. If you picture the part of Earth closest to the moon, it’s easy to see that the ocean is drawn toward the moon. That’s because gravity depends in part on how close two


What is the term given to the study of the weather?

What do you call a person who studies weather? | Reference.com What do you call a person who studies weather? A: Quick Answer A person who uses scientific methods to study, observe or forecast atmospheric patterns and weather events is known as a meteorologist. This field can be further divided into a number of differing job types, including broadcasting, teaching, researching and forensic meteorology. Full Answer The most common undergraduate degrees associated with this profession include physics, chemistry and mathematics prior to attaining an advanced degree in meteorology. Known as "the science of the atmosphere," a meteorologist is tasked with predicting the shifts in weather and climate that can affect the lives of the public. Many meteorologists work closely with other Earth scientists, including oceanographers and hydrologists, while communicating vital weather information to governments, media outlets and industry leaders.


What is the name given to the outermost layer of the Earth?

What is the outer layer of the Earth called? | Reference.com What is the outer layer of the Earth called? A: Quick Answer Containing everything from the ocean basins to continents, the crust is the outermost layer of the Earth. Overall, the crust makes up very little of the Earth's mass, so the other layers, which are the mantle, outer core and inner core, are much thicker. Full Answer Metamorphic, igneous and sedimentary rocks appear on the Earth's crust. At most, the crust's thickness is about 45 miles, and beneath that is a section of semi-solid rock, known as the mantle. Beneath the mantle is the Earth's outer core, which is a liquid layer of iron, and the inner core, which is a solid layer of iron and nickel under extreme pressure.


Which country produces the world's largest quantity of municipal waste per person per year?

Global Municipal Solid Waste Continues to Grow | Worldwatch Institute Global Municipal Solid Waste Continues to Grow OECD nations generate over two kilograms of municipal solid waste per person every day.  (Photo credit: WRS Italia) Growing prosperity and urbanization could double the volume of municipal solid waste annually by 2025, challenging environmental and public health management in the world’s cities, according to new research conducted for our Vital Signs Online service. Although some of this waste is eventually recycled, the doubling of waste that current projections indicate would bring the volume of municipal solid waste—or MSW—from today’s 1.3 billion tons per year to 2.6 billion tons. As defined in the report, MSW consists of organic material, paper, plastic, glass, metals, and other refuse collected by municipal authorities, largely from homes, offices, institutions, and commercial establishments. MSW is a subset of the larger universe of waste and typically does not include waste collected outside of formal municipal programs. Nor does it include the sewage, industrial waste, or construction and demolition waste generated by cities. And of course MSW does not include rural wastes. MSW is measured before disposal, and data on it often include collected material that is later diverted for recycling. MSW tends to be generated in much higher quantities in wealthier regions of the world. Members of the Organisation for Economic Co-operation and Development  (OECD), a group of 34 industrialized nations, lead the world in MSW generation, at nearly 1.6 million tons per day. By contrast, sub-Saharan Africa produces less than one eighth as much, some 200,000 tons per day. The list of top 10 MSW-generating countries includes four developing nations (Brazil, China, India, and Mexico) in part because of the size of their urban populations and in part because their city dwellers are prospering and adopting high-consumption lifestyles. Although the United States leads the world in MSW output at some 621,000 tons per day, China is a relatively close second, at some 521,000 tons. Even among the top 10, however, there is a wide range of output: the United States generates nearly seven times more urban refuse than France, in tenth position, does. Urbanization and income levels also tend to determine the type of waste generated. The share of inorganic materials in the waste stream, including plastics, paper, and aluminum, tends to increase as people grow wealthier and move to cities. Waste flows in rural areas, in contrast, are characterized by a high share of organic matter, ranging from 40 to 85 percent.Similarly, organic waste accounts for more than 60 percent of MSW in low-income countries, but only a quarter of the waste stream in high-income countries. Roughly a quarter of the world’s garbage is diverted to recycling, composting, or digestion—waste management options that are environmentally superior to landfills and incinerators. Recycling rates vary widely by country. In the United States, the recycled share of MSW grew from less than 10 percent in 1980 to 34 percentin 2010, and similar increases have been seen in other countries, especially industrial ones. The growing interest in MSW recovery is driven by a maturation of regulations and of markets for post-consumer materials. The global market for scrap metal and paper is at least $30 billion per year, according to the World Bank . The UN Environment Programme  (UNEP) estimates the market for waste management, from collection through recycling, to be some $400 billion worldwide. Yet UNEP also estimates that to “green” the waste sector would require, among other things, a 3.5-fold increase in MSW recycling at the global level, including nearly complete recovery of all organic material through composting or conversion to energy. The gold standard for MSW will be to integrate it into a materials management approach known as a “circular economy,” which involves a series of policies to reduce the use of some materials and to reclaim or recycle most of the rest. Japan h