What are the two main veins in the neck, returning blood from the brain to the heart?

Cardiovascular System of the Head and Neck Home > Cardiovascular System > Cardiovascular System of the Head and Neck Cardiovascular System of the Head and Neck The cardiovascular system of the head and neck includes the vital arteries that provide oxygenated blood to the brain and organs of the head, including the mouth and eyes. It also includes the veins that return deoxygenated blood from these organs to the heart. Among these blood vessels are several unique and important structures that have evolved to help maintain the continuous flow of blood to the brain. The human brain is so powerful and metabolically active that it uses about 20% of all of the oxygen and glucose taken in by the body each day.... 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 Change View Angle Full Cardiovascular System of the Head and Neck Description [Continued from above] . . . Any interruption in the blood flow to the brain very quickly results in the decline of mental function, loss of consciousness, and eventually death if not corrected. Oxygenated blood enters the neck from the trunk through four major arteries: the left and right vertebral arteries and the left and right common carotid arteries. The vertebral arteries travel through the transverse foramina of the cervical vertebrae before entering the skull at the foramen magnum and joining at the base of the brain to form the basilar artery. From there the basilar artery provides blood to the posterior structures of the brain, including the brain stem, cerebellum, and cerebrum. The left and right carotid arteries each divide in the neck to form the left and right internal carotid as well as the left and right external carotid arteries. The internal carotid arteries pass into the skull inferior to the brain through the left and right carotid foramina. At the base of the brain, the internal carotid arteries branch off into the left and right anterior cerebral arteries and the left and right middle cerebral arteries that supply blood to the middle and anterior regions of the brain. At the base of the brain several communicating arteries form anastomoses, or passages, between the left and right posterior cerebral, left and right internal carotid, and left and right anterior cerebral arteries. These arteries collectively form a ring of blood vessels known as the Circle of Willis. The Circle of Willis provides insurance that the brain will continue to receive blood flow in the event that one of its major arteries is blocked by allowing blood flow between all of the major arteries to all of the regions of the brain. In the neck and head exterior to the skull, the external carotid artery provides blood flow to the skin, muscles, and organs. Several major arteries - including the facial, superficial temporal, and occipital arteries - branch off from the external carotid to provide blood to the many superficial structures of the head. Three pairs of major veins return deoxygenated blood from the tissues of the head and neck to the heart. The left and right vertebral veins descend through the transverse foramina of the cervical vertebrae to drain blood from the spinal cord, cervical vertebrae, and muscles of the neck. In the head, superficial structures on the exterior of the skull are drained by the pair of external jugular veins, which descend through the neck lateral to the vertebral veins. Most importantly, the brain is drained by a group of large cavities in the dura mater layer of the meninges known as dural venous sinuses. Blood collected in these sinuses drains into the largest veins in the head and neck - the left and right internal jugular veins. The internal jugular veins collect blood from the brain as well as the superficial structures of the head and neck before descending through the neck towards the heart. Prepared by Tim Taylor, Anatomy and Physiology Instructor


What is the term fro a series of uncontrollable intakes of air caused by sudden spasms of the diaphragm?

Round One Jeopardy Template The name of Dr. Sieuss's egg-hatching elephant 100 Well-known Tasmanian-born leading lady who launched her entertainment career under the name of Queenie O'Brien. 100 What is the kitchen? Room in the average American home that is the scene of the greatest number of arguments. 100 The distance between bases on a little league baseball field. 100 The part of the brain that regulates physiological stability. 200 Clark Kent's high school sweetheart 200 Yves Montand was born in this country. 200 What is Truth or Consequences? Current name of the town that was formerly Hot Springs, New Mexico, that was re-named in 1960 by its citizens in honor of a popular radio show. 200 First sport in which women were invited to compete at the Olympics. 200 What is Les Miserables, by Victor Hugo, with 823 words Novel containing the longest sentence in literature 300 What are George and Michael? Brummel was George Geste was Michael The real names of Beau Brummel and Beau Geste. 300 What are Patience and Fortitude?  (Names were given by Mayor Fiorello LaGuardia.) Names of the two landmark stone lions sitting in front of the New York Public Libaray at Fifth Avenue and 42nd Street in New York City. 300 What is bicycle moto x (cross)? In cross-country bike racing, what the initials BMX stand for. 300 What are hiccups? DOUBLE JEOPARDY!!! Term for a series of uncontrollable intakes of air caused by sudden spasms of the diaphragm. 400 What is The Little Engine That Could? Famous book that begins: "Chug, chug, chug. Puff, puff, puff." 400 Who is Peter Lorre? Famous actor who prepared for a career in psychiatry - studying and working with pioneer psychoanalysts Sigmund Freud and Alfred Adler - before he turned to performing. 400 What are six months? Time - in months - the average American motorist spends during his lifetime waiting for red lights to turn green. 400 Who is Jackie Robinson?  (He later gained national fame playing professional baseball.) In 1939, the famous American athlete who starred on UCLA's undefeated football team and was the top scorer in the Pacific Coast Conference for basketball. 400 What is the retina?


Which part of the eye contains about 137 million light-sensitive cells in one square inch?

Eye | Creation Facts Creation Facts Evidence From Anatomy September 13th, 2009 The eye is an incredibly complex organ that moves 100,000 times in an average day. Numerous muscles and tear ducts are in place to keep the eye constantly moist, protected, and functional. Our eyes process 1.5 million bits of information simultaneously and provide 80% of the sensory stimulation sent to the brain. They receive light images traveling at 186,000 miles per second through the iris, which opens or closes to let in just the right amount of light. These images travel through a lens, made of transparent cells, which focuses them on the retina at the back of the eyeball. The retina covers less than one square inch of surface, yet this square inch contains approximately 137 million light-sensitive receptor  cells. Approximately 130 million are rod cells (designed specifically to see in black and white), and 7 million are cone cells (allowing color vision). Finally, the image is sent at a rate of 300 miles per hour to the brain for processing. How could all of this have come about by some step-by-step, random-chance evolutionary process? Mankind has designed and patterned the camera after the eye. It is only reasonable to acknowledge that the eye, which is an infinitely more complex instrument, was also designed by intelligence.


What is the more common name for the tympanic membrane?

What is the more common name for the tympanic membrane ? - Euask.com What is the more common name for the tympanic membrane ? 5 Created by expert102, 459 days ago, 352 views What is the more common name for the tympanic membrane ? √ Best Answer


What is a Red Blood Cell? (with pictures) What is a Red Blood Cell? Originally Written By: Michael Anissimov Revised By: Jillian O Keeffe Edited By: Bronwyn Harris Last Modified Date: 08 December 2016 Copyright Protected: Top 10 facts about the world A red blood cell, or erythrocyte , is the most common type of cell in blood. It carries oxygen throughout the circulatory system, from the lungs to the rest of the body, and brings carbon dioxide waste back the other way. All of the body's tissues are dependent upon oxygen from these cells — if the flow is cut off, the tissue dies. There are several medical conditions associated with red blood cells specifically, including sickle-cell anemia, thalassemia, and spherocytosis, but changes in the amount of these cells can also be a sign of other disorders. Characteristics Red blood cells have a diameter of about 6 to 8 micrometers (millionths of a meter), which is similar in size to most cells in the body. They are round and red, with a depression in the center. Adult humans have 20 to 30 trillion of these cells in their bodies, with men having more on average than women, and each one lives for about 120 days before being broken down. They are very flexible, which is important for their functioning, since they often have to squeeze through small openings. Ad Function The main purpose of red blood cells is to transport oxygen and carbon dioxide through the circulatory system. The reason they can do this is that they contain an iron-containing protein called hemoglobin, which binds to oxygen. When the oxygen and the hemoglobin combine, they cause the cells to become bright red. This is why blood looks red when it goes outside of the body as well — when exposed to the open through a cut, the cells become exposed to a lot of atmospheric oxygen. Once all the oxygen connected to the cells is used up, then they collect carbon dioxide and other waste gases from the body and bring it back to the lungs, where they swap it for oxygen and start the cycle again. Related Disorders There are a variety of medical disorders associated with red blood cells, with one of the most common being sickle-cell disease. This is a genetic disorder that causes the cells to become stiff and sickle-shaped. This makes them unable to move properly throughout the circulatory system, and can lead to a variety of problems, including strokes, blindness, and chronic pain. Spherocytosis is another genetic condition that changes the shape of cells and makes them brittle, but unlike sickle-cell disease, it makes them spherical. Several other conditions cause red blood cell abnormalities by disrupting the proper production of hemoglobin. This includes thalassemia, a genetic disorder that causes abnormal hemoglobin molecules, and pernicious anemia, in which the body doesn't absorb enough B12, which is needed for making hemoglobin. Additionally, conditions like G6PD deficiency, hemolytic disease of the fetus and newborn, and aplastic anemia can cause problems with the creation and life of red blood cells. Besides conditions that affect the cells themselves, having an increase or decrease in the number of red blood cells in the body can be a symptom of several conditions. A high red blood cell count, also called polycythemia, can be caused by poor circulation to the kidneys, genetic heart problems, Chronic Obstructive Pulmonary Disease ( COPD ), and pulmonary fibrosis . Some people are also born with genetic variants that cause them to have higher than normal red blood cell counts. A lower than normal count can be a sign of poor nutrition, problems with bone marrow, and leukemia , among other things. Ad


What is the scientific name for the windpipe?

Windpipe | Define Windpipe at Dictionary.com windpipe the trachea of an air-breathing vertebrate. Origin of windpipe 1520-30; wind 1 + pipe 1 Dictionary.com Unabridged Examples from the Web for windpipe Expand Contemporary Examples After using her hands to clear her windpipe, she freed her eyes from the embers that were blinding her vision. Mailer's Final Gift Lawrence Schiller February 4, 2009 Historical Examples My brother felt that it must be the windpipe, because when you kicked someone there he lost his breath. The soreness in the throat may extend down the windpipe, and membranes may form there. Diphtheria Public Health Service British Dictionary definitions for windpipe Expand a nontechnical name for trachea (sense 1) related adjective tracheal Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012 Word Origin and History for windpipe Expand "trachea," 1520s, from wind (n.1) in the "breath" sense + pipe (n.1). Online Etymology Dictionary, © 2010 Douglas Harper


Where do the Graafian follicles develop?

Graafian follicle | definition of graafian follicle by Medical dictionary Graafian follicle | definition of graafian follicle by Medical dictionary http://medical-dictionary.thefreedictionary.com/graafian+follicle Related to graafian follicle: ovarian follicle , ovulation , corpus luteum graafian follicle  [graf´e-an] a small sac, embedded in the ovary , that encloses an ovum . At puberty each ovary has a large number of immature follicles ( primordial follicles ), each of which contains an undeveloped egg cell. About every 28 days between puberty and the onset of menopause, one of the follicles develops to maturity, or ripens, into a graafian follicle (or vesicular ovarian follicle ). As it ripens, it increases in size. The ovum within becomes larger, the follicular wall becomes thicker, and fluid collects in the follicle and surrounds the ovum. The follicle also secretes estradiol, the hormone that prepares the endometrium to receive a fertilized egg. As the follicle matures, it moves to the surface of the ovary and forms a projection. When fully mature, the graafian follicle breaks open and releases the ovum, which passes into the fallopian tubes . This release of the ovum is called ovulation ; it occurs midway in the menstrual cycle, generally about 14 days after the commencement of the menstrual flow. The released ovum travels down the tube to the uterus, a process that takes about 3 days. Meanwhile, the empty graafian follicle in the ovary becomes filled with cells containing a yellow substance, the corpus luteum . The corpus luteum secretes progesterone , a hormone that causes further change in the endometrium, allowing it to provide a good milieu in which a zygote (fertilized ovum) can grow through the stages of gestation to become a fetus . ve·sic·u·lar o·var·i·an fol·li·cle [TA] a follicle in which the primary oocyte attains its full size and is surrounded by an extracellular glycoprotein layer (zona pellucida) that separates it from a peripheral layer of follicular cells permeated by one or more fluid-filled antra; the primary oocyte occupies the cumulus oophorus; the theca of the follicle develops into internal and external layers. Any of the fluid-filled vesicles in the mammalian ovary containing a maturing ovum. graafian follicle [grä′fē·ən, -grā′-] Etymology: Reijnier de Graaf, Dutch physician, 1641-1673; L, folliculus, small bag a mature ovarian vesicle, measuring about 10 to 12 mm in diameter, that ruptures during ovulation to release the ovum. Many primary ovarian follicles, each containing an immature ovum about 35 μm in diameter, are embedded near the surface of the ovary, just below the tunica albuginea. Under the influence of the follicle-stimulating hormone from the adenohypophysis, one ovarian follicle ripens into a graafian follicle during the proliferative phase of each menstrual cycle. The cells that form the graafian follicle are arranged in a layer three to four cells thick around a relatively large volume of follicular fluid. Within the follicle the ovum grows to about 100 μm in diameter, ruptures, and is swept into the fimbriated opening of the uterine tube. The cavity of the follicle collapses when the ovum is released, and the remaining follicular cells greatly enlarge to become the corpus luteum. If the ovum is fertilized, the corpus luteum grows and becomes the corpus luteum of pregnancy, which degenerates by the end of 9 months and has a diameter of about 30 mm. As the ovarian follicle ripens into the graafian follicle, it produces estrogen, which stimulates the proliferation of the endometrium and the enlargement of the uterine glands. The growing corpus luteum produces progesterone, which triggers endometrial gland secretion and prepares the uterus to receive the fertilized ovum. If the ovum is not fertilized, the graafian follicle forms the corpus luteum of menstruation, which degenerates before the next menstrual cycle, leaving the small scarred corpus albicans. ve·sic·u·lar o·var·i·an fol·li·cle (vĕ-sik'yū-lăr ō-var'ē-ăn fol'i-kĕl) [TA] A follicle in which the oocyte attains its f


Pisiform (bone) - RightDiagnosis.com Pisiform (bone) Pisiform (bone): a small wrist bone that articulates only with the triquetral. Source: WordNet 2.1 Pisiform (bone): A pea-shaped carpal bone that actually sits in the tendon of the flexor carpi ulnaris muscle. Source: MeSH 2007 Terms associated with Pisiform (bone): Terms Similar to Pisiform (bone): Source - WordNet 2.1 Hierarchical classifications of Pisiform (bone) The following list attempts to classify Pisiform (bone) into categories where each line is subset of the next. WordNet 2.1 Search to find out more about Pisiform (bone):    Search Specialists by State and City   By using this site you agree to our Terms of Use . Information provided on this site is for informational purposes only; it is not intended as a substitute for advice from your own medical team. The information on this site is not to be used for diagnosing or treating any health concerns you may have - please contact your physician or health care professional for all your medical needs. Please see our Terms of Use .


What is the scientific name for the kneecap?

What is the scientific name for the knee cap? - YouTube What is the scientific name for the knee cap? Want to watch this again later? Sign in to add this video to a playlist. Need to report the video? Sign in to report inappropriate content. The interactive transcript could not be loaded. Loading... Rating is available when the video has been rented. This feature is not available right now. Please try again later. Published on Aug 1, 2013 This improves the knowledge of the children indirectly as they never know that they are learning. - Category


Neuroscience For Kids - The Skull you are here: home > explore > the skull Neuroscience For Kids the skull Your 3 pound (1.4 kg) brain needs a home...your skull! Your brain is protected by several bones. There are eight bones that surround your brain: one frontal bone; two parietal bones, two temporal bones, one occipital bone, one sphenoid bone and one ethmoid bone. These eight bones make up the cranium. Another 14 bones in the face make up the entire skull. There are also three small bones in each ear . Also protecting your brain are three layers of tissue called the meninges . A few of the bones have been colored in the diagram below. There is a large opening, called the foramen magnum, located in the back of the occipital bone. This is where the medulla ends and projects out of the skull. Smaller holes in the skull, called foramina, allow nerves and blood vessels to enter and leave the cranium. The picture on the left shows the base of the skull. The places in the skull where the bones come together are called sutures. These sutures are flexible in young children, but become fixed as they age. Copyright © 1996-2011, Eric H. Chudler, All Rights Reserved.


What is the name of the large muscle just beneath the lungs?

Your Lungs & Respiratory System Your Lungs & Respiratory System What's something that you do all day, every day, no matter where you are or who you're with? (a) think about what's for lunch tomorrow (b) put your finger in your nose (c) hum your favorite song (d) breathe It's possible that some kids could say (a) or (c) or that others might even say — yikes! — (b). But every single person in the world has to say (d). Breathing air is necessary for keeping humans (and many animals) alive. And the two parts that are large and in charge when it comes to breathing? If you guessed your lungs, you're right! Your lungs make up one of the largest organs in your body, and they work with your respiratory system to allow you to take in fresh air, get rid of stale air, and even talk. Let's take a tour of the lungs! Locate Those Lungs Your lungs are in your chest, and they are so large that they take up most of the space in there. You have two lungs, but they aren't the same size the way your eyes or nostrils are. Instead, the lung on the left side of your body is a bit smaller than the lung on the right. This extra space on the left leaves room for your heart. Your lungs are protected by your rib cage, which is made up of 12 sets of ribs. These ribs are connected to your spine in your back and go around your lungs to keep them safe. Beneath the lungs is the diaphragm (say: DY-uh-fram), a dome-shaped muscle that works with your lungs to allow you to inhale (breathe in) and exhale (breathe out) air. You can't see your lungs, but it's easy to feel them in action: Put your hands on your chest and breathe in very deeply. You will feel your chest getting slightly bigger. Now breathe out the air, and feel your chest return to its regular size. You've just felt the power of your lungs! continue A Look Inside the Lungs From the outside, lungs are pink and a bit squishy, like a sponge. But the inside contains the real lowdown on the lungs! At the bottom of the trachea (say: TRAY-kee-uh), or windpipe, there are two large tubes. These tubes are called the main stem bronchi (say: BRONG-kye), and one heads left into the left lung, while the other heads right into the right lung. Each main stem bronchus (say: BRONG-kuss) — the name for just one of the bronchi — then branches off into tubes, or bronchi, that get smaller and even smaller still, like branches on a big tree. The tiniest tubes are called bronchioles (say: BRONG-kee-oles), and there are about 30,000 of them in each lung. Each bronchiole is about the same thickness as a hair. At the end of each bronchiole is a special area that leads into clumps of teeny tiny air sacs called alveoli (say: al-VEE-oh-lie). There are about 600 million alveoli in your lungs and if you stretched them out, they would cover an entire tennis court. Now that's a load of alveoli! Each alveolus (say: al-VEE-oh-luss) — what we call just one of the alveoli — has a mesh-like covering of very small blood vessels called capillaries (say: CAP-ill-er-ees). These capillaries are so tiny that the cells in your blood need to line up single file just to march through them. All About Inhaling When you're walking your dog, cleaning your room, or spiking a volleyball, you probably don't think about inhaling (breathing in) — you've got other things on your mind! But every time you inhale air, dozens of body parts work together to help get that air in there without you ever thinking about it. As you breathe in, your diaphragm contracts and flattens out. This allows it to move down, so your lungs have more room to grow larger as they fill up with air. "Move over, diaphragm, I'm filling up!" is what your lungs would say. And the diaphragm isn't the only part that gives your lungs the room they need. Your rib muscles also lift the ribs up and outward to give the lungs more space. At the same time, you inhale air through your mouth and nose, and the air heads down your trachea, or windpipe. On the way down the windpipe, tiny hairs called cilia (say: SILL-ee-uh) move gently to keep mucus and dirt out of the lungs. The air then goes thro


The Thyroid (Human Anatomy): Picture, Function, Definition, Location in the Body, and More Next The thyroid is a butterfly-shaped gland that sits low on the front of the neck. Your thyroid lies below your Adam’s apple, along the front of the windpipe. The thyroid has two side lobes, connected by a bridge (isthmus) in the middle. When the thyroid is its normal size, you can’t feel it. Brownish-red in color, the thyroid is rich with blood vessels. Nerves important for voice quality also pass through the thyroid. The thyroid secretes several hormones, collectively called thyroid hormones. The main hormone is thyroxine, also called T4. Thyroid hormones act throughout the body, influencing metabolism, growth and development, and body temperature. During infancy and childhood, adequate thyroid hormone is crucial for brain development. Thyroid Conditions Goiter : A general term for thyroid swelling. Goiters can be harmless, or can represent iodine deficiency or a condition associated with thyroid inflammation called Hashimoto’s thyroiditis. Thyroiditis : Inflammation of the thyroid, usually from a viral infection or autoimmune condition. Thyroiditis can be painful, or have no symptoms at all. Hyperthyroidism : Excessive thyroid hormone production. Hyperthyroidism is most often caused by Graves disease or an overactive thyroid nodule. Hypothyroidism : Low production of thyroid hormone. Thyroid damage caused by autoimmune disease is the most common cause of hypothyroidism . Graves disease : An autoimmune condition in which the thyroid is overstimulated, causing hyperthyroidism. Thyroid cancer : An uncommon form of cancer, thyroid cancer is usually curable. Surgery, radiation, and hormone treatments may be used to treat thyroid cancer. Thyroid nodule : A small abnormal mass or lump in the thyroid gland. Thyroid nodules are extremely common. Few are cancerous. They may secrete excess hormones, causing hyperthyroidism, or cause no problems.  Thyroid storm : A rare form of hyperthyroidism in which extremely high thyroid hormone levels cause severe illness. Continued Thyroid Tests Anti-TPO antibodies : In autoimmune thyroid disease, proteins mistakenly attack the thyroid peroxidase enzyme, which is used by the thyroid to make thyroid hormones. Thyroid ultrasound: A probe is placed on the skin of the neck, and reflected sound waves can detect abnormal areas of thyroid tissue. Thyroid scan : A small amount of radioactive iodine is given by mouth to get images of the thyroid gland. Radioactive iodine is concentrated within the thyroid gland.  Thyroid biopsy : A small amount of thyroid tissue is removed, usually to look for thyroid cancer. Thyroid biopsy is typically done with a needle.  Thyroid stimulating hormone (TSH): Secreted by the brain, TSH regulates thyroid hormone release. A blood test with high TSH indicates low levels of thyroid hormone (hypothyroidism), and low TSH suggests hyperthyroidism. T3 and T4 (thyroxine) : The primary forms of thyroid hormone, checked with a blood test.  Thyroglobulins : A substance secreted by the thyroid that can be used as a marker of thyroid cancer. It is often measured during follow-up in patients with thyroid cancer. High levels indicate recurrence of the cancer.  Other imaging tests: If thyroid cancer has spread (metastasized), tests such as CT scans , MRI scans , or PET scans can help identify the extent of spread.  Thyroid Treatments Thyroid surgery (thyroidectomy): A surgeon removes all or part of the thyroid in an operation. Thyroidectomy is performed for thyroid cancer, goiter,  or hyperthyroidism.  Antithyroid medications : Drugs can slow down the overproduction of thyroid hormone in hyperthyroidism. Two common antithyroid medicines are methimazole and propylthiouracil.  Radioactive iodine : Iodine with radioactivity that can be used in low doses to test the thyroid gland or destroy an overactive gland. Large doses can be used to destroy cancerous tissue. External radiation : A beam of radiation is directed at the thyroid, on multiple appointments. The high-energy rays help kill thyroid c


Which organ in the body stores excess sugar as glycogen?

The Liver & Blood Sugar :: Diabetes Education Online Diabetes Education Online « Controlling Blood Sugar During a meal, your liver stores sugar for later. When you’re not eating, the liver supplies sugar by turning glycogen into glucose in a process called glycogenolysis. The liver both stores and produces sugar… The liver acts as the body’s glucose (or fuel) reservoir, and helps to keep your circulating blood sugar levels and other body fuels steady and constant. The liver both stores and manufactures glucose depending upon the body’s need. The need to store or release glucose is primarily signaled by the hormones insulin and glucagon . During a meal, your liver will store sugar, or glucose, as glycogen for a later time when your body needs it. The high levels of insulin and suppressed levels of glucagon during a meal promote the storage of glucose as glycogen. The liver makes sugar when you need it…. When you’re not eating – especially overnight or between meals, the body has to make its own sugar. The liver supplies sugar or glucose by turning glycogen into glucose in a process called glycogenolysis. The liver also can manufacture necessary sugar or glucose by harvesting amino acids, waste products and fat byproducts. This process is called gluconeogenesis. The liver also makes another fuel, ketones, when sugar is in short supply…. When your body’s glycogen storage is running low, the body starts to conserve the sugar supplies for the organs that always require sugar. These include: the brain, red blood cells and parts of the kidney. To supplement the limited sugar supply, the liver makes alternative fuels called ketones from fats. This process is called ketogenesis. The hormone signal for ketogenesis to begin is a low level of insulin. Ketones are burned as fuel by muscle and other body organs. And the sugar is saved for the organs that need it. The terms “gluconeogenesis, glycogenolysis and ketogenesis” may seem like complicated concepts or words on a biology test. Take a moment to review the definitions and illustrations above. When you have diabetes, these processes can be thrown off balance, and if you fully understand what is happening, you can take steps to fix the problem. Gluconeogenesis? Glycogenolysis? Ketogenesis? What are they? You need to know. Self-assessment Quiz Self assessment quizzes are available for topics covered in this website. To find out how much you have learned about  Facts about Diabetes, take our self assessment quiz when you have completed this section.  The quiz is multiple choice. Please choose the single best answer to each question. At the end of the quiz, your score will display. If your score is over 70% correct, you are doing very well. If your score is less than 70%, you can return to this section and review the information.


What name is given to the small bones which form the spinal column?

Bones of the Spinal Column Home  »  Spine Articles  »  Spinal Column Articles  »  Bones of the Spinal Column Bones of the spinal column  Sections The spinal column is made up of small bones called vertebrae. Offering support and structure to the human body, these bones are some of the most complex bones in the human body. Each vertebra has a specific function, working together to protect the spinal cord. Segments of the spine The spinal column is composed of a number of different segments, including the cervical (neck), thoracic (middle back) and lumbar (lower back) segments. The sacrum and coccyx are bones that are found at the base of the spine. Cervical — The cervical region usually consists of seven vertebrae (C1–7), which are the smallest bones of the spinal column. The atlas (C1) directly supports the head, while the axis (C2) provides the head with pivoting motion. The remaining bones (C3–7) allow the head to move from side to side, backward and forward. Thoracic — In most cases, twelve vertebrae (T1–12) form the thoracic region, which is generally considered the sturdiest area of the spine. This region serves to protect the organs located in the chest, so spinal mobility is limited more in the thoracic region than in the cervical and lumbar regions. Thoracic vertebrae are further supported by the attached rib cage. Lumbar — The final segment in the spine is the lumbar area. This segment usually consists of five (sometimes six) individual vertebrae (L1–5). These bones are the largest in the spinal column because they must bear the weight of the body. Sacrum — This triangular bone sits between the pelvic bones and serves to protect the pelvic organs. Consisting of five fused vertebrae (S1–5), the sacrum attaches to the L5 vertebra above and the coccyx below. Coccyx — A vestigial remnant of a tail, the coccyx is commonly known as the “tailbone.” Many essential ligaments and muscles attach to this bone. The bones of the spinal column, as well as the spinal cord, nerve roots, muscles, tendons and ligaments, can be afflicted by trauma (accidents or injuries) as well as degenerative spine conditions. When this happens, it can lead to long-term chronic pain and limited mobility. Treatment for painful spine conditions At Laser Spine Institute, we understand the importance of a healthy spine. If you are experiencing chronic neck or back pain that is affecting your quality of life, consider treatment at our outpatient surgery center. Our surgeons specialize exclusively in treating neck and back pain with minimally invasive, outpatient spine surgery . These procedures are a safer and effective alternative to traditional open neck and back surgery, offering you a number of benefits. Having helped more than 60,000 patients since 2005, our surgeons are available in cities across the country. Learn more about our advanced techniques For more information about the benefits of minimally invasive spine surgery, please call a member of our Care Team today . With a 96 patient satisfaction rate, our goal is to always provide you with the ultimate in care and comfort, so that you can return to your normal daily activities. Want to chat?


Where in the body are the cerebellum, the medulla and the hypothalamus?

Brain – Human Brain Diagrams and Detailed Information Brain Cortices Full Brain Description [Continued from above] . . . in the study of the body; doctors, psychologists, and scientists are continually endeavoring to learn exactly how the many structures of the brain work together intricately to create our powerful human mind. Anatomy of the Brain There are different ways of dividing the brain anatomically into regions. Let’s use a common method and divide the brain into three main regions based on embryonic development: the forebrain, midbrain and hindbrain. Under these divisions: The forebrain (or prosencephalon) is made up of our incredible cerebrum, thalamus, hypothalamus and pineal gland among other features. Neuroanatomists call the cerebral area the telencephalon and use the term diencephalon (or interbrain) to refer to the area where our thalamus, hypothalamus and pineal gland reside. The midbrain (or mesencephalon), located near the very center of the brain between the interbrain and the hindbrain, is composed of a portion of the brainstem. The hindbrain (or rhombencephalon) consists of the remaining brainstem as well as our cerebellum and pons. Neuroanatomists have a word to describe the brainstem sub-region of our hindbrain, calling it the myelencephalon, while they use the word metencephalon in reference to our cerebellum and pons collectively. Before exploring these different regions of the brain, first let’s define the important types of cells and tissues that are the building blocks of them all. Histology Brain cells can be broken into two groups: neurons and neuroglia. Neurons, or nerve cells, are the cells that perform all of the communication and processing within the brain. Sensory neurons entering the brain from the peripheral nervous system deliver information about the condition of the body and its surroundings. Most of the neurons in the brain’s gray matter are interneurons, which are responsible for integrating and processing information delivered to the brain by sensory neurons. Interneurons send signals to motor neurons, which carry signals to muscles and glands. Neuroglia, or glial cells, act as the helper cells of the brain; they support and protect the neurons. In the brain there are four types of glial cells: astrocytes, oligodendrocytes, microglia, and ependymal cells. Astrocytes protect neurons by filtering nutrients out of the blood and preventing chemicals and pathogens from leaving the capillaries of the brain. Oligodendrocytes wrap the axons of neurons in the brain to produce the insulation known as myelin. Myelinated axons transmit nerve signals much faster than unmyelinated axons, so oligodendrocytes accelerate the communication speed of the brain. Microglia act much like white blood cells by attacking and destroying pathogens that invade the brain. Ependymal cells line the capillaries of the choroid plexuses and filter blood plasma to produce cerebrospinal fluid. The tissue of the brain can be broken down into two major classes: gray matter and white matter. Gray matter is made of mostly unmyelinated neurons, most of which are interneurons. The gray matter regions are the areas of nerve connections and processing. White matter is made of mostly myelinated neurons that connect the regions of gray matter to each other and to the rest of the body. Myelinated neurons transmit nerve signals much faster than unmyelinated axons do. The white matter acts as the information highway of the brain to speed the connections between distant parts of the brain and body. Now let’s begin exploring the main structures of our awesome human brain. HINDBRAIN (RHOMBENCEPHALON) Brainstem Connecting the brain to the spinal cord, the brainstem is the most inferior portion of our brain. Many of the most basic survival functions of the brain are controlled by the brainstem. The brainstem is made of three regions: the medulla oblongata, the pons, and the midbrain. A net-like structure of mixed gray and white matter known as the reticular formation is found in all three regions of the brainstem. The reticular f


What makes up 60-70% of human body weight?

Water properties: The water in you (Water Science School)   Back to previous page The water in you Think of what you need to survive, really just survive. Food? Water? Air? Facebook? Naturally, I'm going to concentrate on water here. Water is of major importance to all living things; in some organisms, up to 90% of their body weight comes from water. Up to 60% of the human adult body is water. According to H.H. Mitchell, Journal of Biological Chemistry 158, the brain and heart are composed of 73% water, and the lungs are about 83% water. The skin contains 64% water, muscles and kidneys are 79%, and even the bones are watery: 31%. Each day humans must consume a certain amount of water to survive. Of course, this varies according to age and gender, and also by where someone lives. Generally, an adult male needs about 3 liters per day while an adult female needs about 2.2 liters per day. Some of this water is gotten in food. Water serves a number of essential functions to keep us all going: A vital nutrient to the life of every cell, acts first as a building material. It regulates our internal body temperature by sweating and respiration The carbohydrates and proteins that our bodies use as food are metabolized and transported by water in the bloodstream; It assists in flushing waste mainly through urination acts as a shock absorber for brain, spinal cord, and fetus forms saliva lubricates joints According to Dr. Jeffrey Utz, Neuroscience, pediatrics, Allegheny University, different people have different percentages of their bodies made up of water. Babies have the most, being born at about 78%. By one year of age, that amount drops to about 65%. In adult men, about 60% of their bodies are water. However, fat tissue does not have as much water as lean tissue. In adult women, fat makes up more of the body than men, so they have about 55% of their bodies made of water. Thus: Babies and kids have more water (as a percentage) than adults. Women have less water than men (as a percentage). People with more fatty tissue have less water than people with less fatty tissue (as a percentage). There just wouldn't be any you, me, or Fido the dog without the existence of an ample liquid water supply on Earth. The unique qualities and properties of water are what make it so important and basic to life. The cells in our bodies are full of water. The excellent ability of water to dissolve so many substances allows our cells to use valuable nutrients, minerals, and chemicals in biological processes. Water's "stickiness" (from surface tension ) plays a part in our body's ability to transport these materials all through ourselves. The carbohydrates and proteins that our bodies use as food are metabolized and transported by water in the bloodstream. No less important is the ability of water to transport waste material out of our bodies. Sources and more information


What are the very narrow blood vessels which form a network between arteries and veins?

Blood vessels - human anatomy organs Blood vessels Tweet BLOOD VESSELS ANATOMY Blood vessels are responsible for the transportation of blood , made up arteries and veins, they creates pathways for the oxygenated blood to travel to their destination and pathways for the used deoxygenated blood to travel back to the heart or lungs . Capillaries are designed to permit the transfer of gasses within the blood, such as the delivery of oxygen and the return of carbon dioxide. The molecules from the tissues use the oxygenated blood plasma for energy and return the molecules of wastes. Blood vessels form these pathways to reach every living cell within the human body for this gaseous exchange. The network formed by the blood vessels is tubular, extensive, and in many ways fragile to outside influences. BLOOD VESSELS FUNCTIONS As the blood leaves the heart, they are filled with molecules of necessary oxygen, and traverse a passageway of progressively smaller tubular networks known as (in order) arteries, arterioles, and capillaries. The microscopic capillaries are responsible for the conjoining of arterial flow and venous flow. Capillaries create the environment for the actual gaseous exchange. As blood returns to the heart for more oxygen it passes through a tubular network of progressively larger diameter known as (in order) venules and veins. Anastomosis is the convergence arteries. While there are several places throughout the body where this process of anastomosis occurs, this includes the necks of the humerus and femur . Anastomosis occurs in areas that require a constant supply of oxygenated blood. BLOOD VESSELS DIAGRAM Image: Blood Vessels Blood vessels are comprised of three layers which form the tubular network. The outermost layer is comprised of connective tissue. This layer is known as either tunica externa or advetitia. The middle layer is known as tunica media and is comprised of thin muscular tissue. Throughout this stratum there are diverse amounts of elastic fibers. The inner most layer is a combination of simple squamous epithelium and elastin. The layer of squamous epithelium is termed as the endothelium. All blood vessels have this inner layer as their inner lining. BLOOD VESSELS STRUCTURE The structure of a capillary is a bit different. They have a basement membrane for support and have only a endothelium layer. Arteries and veins are nearly the same, with the exception of a few vital differences in their structure. The arteries are responsible for the transport of blood away from the heart while veins are responsible for the transport of blood back to the heart. An artery that is compared with the same sized vein is going to have more muscle in their structure. Cross section comparisons show that arteries are more circular than veins. Veins generally do not fill to capacity and therefore have a more relaxed shape. Veins have the capability to expand when filled with additional blood and make up the body’s venous reservoirs. Arteries are also devoid of valves , which veins are equipped with in their structure. ARTERIES In order for the arteries to expand when the heart fills them with blood and retract when there is absence of blood, the arteries have layers of elastic fibers in between their layers of smooth muscle in the tunica media section. The action of expanding and contracting helps create a more even and less volatile rhythmic pattern of alternating systole and diastole action in the smaller arteries and arterioles. The smaller the artery the less elastic fiber is built into their layers of muscle. This creates an even diameter in the smaller arteries. Larger arteries are designed to expand and contract with the rhythm set forth by the heart. ARTERIES FUNCTIONS The small muscular arteries are more rigid, thus they create more resistance through the circulatory system than veins or larger arteries. These small arteries have very narrow lumina, which is also the case with the small arterioles. The smallest of the arteries branch off to form the arterioles. Any artery that is less than 100 micrometers in


What is the ring of bones at the hip called?

Hip bone Anatomy | Bone and Spine You are here: Home / Anatomy / Hip bone Anatomy Hip bone Anatomy Published - By Dr Arun Pal Singh Last Edited Apr 1, 2015 @ 5:16 pm Hip bone is also known as inominate bone or pelvic bone and is formed by fusion of three bones namely ilium, ischium and pubis bones. Hip bone forms part of pelvis and takes part in hip joint articulation. The hip bone is made up of the three parts – the ilium, pubis and ischium. Prior to puberty, the triradiate cartilage separates these constituents. At the age of 15-17, the three parts begin to fuse. Their fusion forms a cup-shaped socket known as the acetabulum, which becomes complete at 20-25 years of age. The head of the femur articulates with the acetabulum to form the hip joint. Thus the hip bone has three articulations – Sacroiliac joint – articulation with sacrum Pubic symphysis – articulation with the other hip bone . Hip joint – articulation with the head of femur. Side determination of Hip Bone Acetabulum is on lateral side Obturator formen lies below the acetabulum, pubis being anterior and ischium posterior Flat expanded part, the ilium is above the acetabulum. Anatomical Position of Hip Bone Pubic tubercle and anterior superior iliac spine lie in same coronal plane . Pelvic surface of pubis is directed backwards and upwards Symphyseal surface of the body of pubis is in the median plane . Ilium Ilium is largest part of the hip bone and forms upper expanded plate in upper part and contributes to acetabulum formation in lower part. Roughly two fifth of acetabulum is contributed by ilium. Upper end of ilium is called iliac crest. Iliac crest is broad, convex, topmost portion of ilium which can be palpated in the flank area. Anterior end of iliac crest is called the anterior superior iliac spine which is a very important anatomical landmark. Iliac crest ends posteriorly in the posterior superior iliac spine [Located about dimple of venus about by a dimple 4 cm lateral to the second sacral spine. ] Iliac crest is divided in to a ventral segment and a dorsal segment which meet at the tubercle. The ventral segment forms more than the anterior two thirds of the crest. The dorsal segment forms less than the posterior one third of the crest. Lower end is fused with ischium and pubis at the acetabulum. Ilium has got three borders [anterior, posterior and medial ] and three surfaces [gluteal, iliac, and a sacropelvic surface]. Borders of Ilium Anterior border of ilium starts at the anterior superior iliac spine and runs downwards to the acetabulum. In upper part , the border has a notch and while its lower part has  anterior inferior iliac spine. Posterior border extends from the posterior superior iliac spine to the upper end of the posterior border of the ischium. It is marked by prominence called posterior inferior iliac spine and lower a large deep notch called the greater sciatic notch. Medial Border is on the inner surface of the ilium from the iliac crest to the iliopubic eminence and separates the iliac fossa from the sacropelvic surface. Its lower rounder part form the iliac part inlet of pelvis or arcuate line . Surfaces of Ilium Gluteal surface is the outer surface of the ilium, which is convex in front and concave behind. Three gluteal lines divide the gluteal surface. The posterior gluteal line is the shortest and extends from a point front of the posterior superior spine to a point of the posterior inferior spine. The anterior gluteal line is the longest , begins about an inch behind the anterior superior spine, runs backwards and then downwards to end at the middle of the upper border of the greater sciatic notch. The inferior gluteal line is not well defined. It begins a little above and behind the anterior inferior spine, runs backwards and downwards to end near the apex of the greater sciatic notch. Inner surface of ilium is divided by medial border into iliac fossa and sacropelvic surface. Iliac fossa is the large concave area on the inner surface of the ilium, situated in front of its medial border. It forms the lateral wall of the fals


What tube connects the kidney to the bladder?

KidneyStones.org Ureter Function The         ureter is a thick-walled tube leading from each kidney, which         carries urine to the bladder. Urine flows down partly by gravity,         but mainly by a wave of contractions, called peristalsis, which         pass several times per minute through the muscle layers of the         urethral walls. Structure Each ureter is a tubular organ measuring about 25 centimeters (ten         to twelve inches) in length beginning at the funnel-shaped renal         pelvis. Within the wall of the ureter are three layers. The inner         layer, or mucous coat, is continuous with the linings of the renal         tubules above and the urinary bladder below. The middle layer,         or the muscular coat, is composed of largely smooth muscle fibers.         The outer layer, or the fibrous coat, is primarily composed of         connective tissue. Each ureter enters the bladder through a tunnel         in the bladder wall, which is angled to prevent the urine from         running back into the ureter, known as reflux, when the bladder         contracts.


What is the name of the structural tissue found in the ear, the nose, and in between the vertebral discs?

Connective Tissues: Loose, Fibrous, and Cartilage About Watch and Favorite Watch Watching this resources will notify you when proposed changes or new versions are created so you can keep track of improvements that have been made. Favorite Favoriting this resource allows you to save it in the “My Resources” tab of your account. There, you can easily access this resource later when you’re ready to customize it or assign it to your students. Connective Tissues: Loose, Fibrous, and Cartilage Connective tissue is found throughout the body, providing support and shock absorption for tissues and bones. Learning Objective Distinguish between the different types of connective tissue Key Points Fibroblasts are cells that generate any connective tissue that the body needs, as they can move throughout the body and can undergo mitosis to create new tissues. Protein fibers run throughout connective tissue, providing stability and support; they can be either collagen , elastic, or reticular fibers. Loose connective tissue is not particularly tough, but surrounds blood vessels and provides support to internal organs. Fibrous connective tissue, which is composed of parallel bundles of collagen fibers, is found in the dermis, tendons, and ligaments. Hyaline cartilage forms the skeleton of the embryo before it is transformed into bone; it is found in the adult body at the tip of the nose and around the ends of the long bones, where it prevents friction at the joints. Fibrocartilage is the strongest of the connective tissues; it is found in regions of the body that experience large amounts of stress and require a high degree of shock absorption, such as between the vertebrae. Terms Full Text Connective Tissues Connective tissues are composed of a matrix consisting of living cells and a non-living substance, called the ground substance. The ground substance is composed of an organic substance (usually a protein) and an inorganic substance (usually a mineral or water). The principal cell of connective tissues is the fibroblast, an immature connective tissue cell that has not yet differentiated. This cell makes the fibers found in nearly all of the connective tissues. Fibroblasts are motile , able to carry out mitosis, and can synthesize whichever connective tissue is needed. Macrophages , lymphocytes , and, occasionally, leukocytes can be found in some of the tissues, while others may have specialized cells. The matrix in connective tissues gives the tissue its density . When a connective tissue has a high concentration of cells or fibers, it has a proportionally-less-dense matrix. The organic portion, or protein fibers, found in connective tissues are either collagen, elastic, or reticular fibers. Collagen fibers provide strength to the tissue, preventing it from being torn or separated from the surrounding tissues. Elastic fibers are made of the protein elastin; this fiber can stretch to one and one half of its length, returning to its original size and shape. Elastic fibers provide flexibility to the tissues. Reticular fibers, the third type of protein fiber found in connective tissues, consist of thin strands of collagen that form a network of fibers to support the tissue and other organs to which it is connected. Loose (Areolar) Connective Tissue Loose connective tissue, also called areolar connective tissue, has a sampling of all of the components of a connective tissue. Loose connective tissue has some fibroblasts, although macrophages are present as well. Collagen fibers are relatively wide and stain a light pink, while elastic fibers are thin and stain dark blue to black . The space between the formed elements of the tissue is filled with the matrix. The material in the connective tissue gives it a loose consistency similar to a cotton ball that has been pulled apart. Loose connective tissue is found around every blood vessel, helping to keep the vessel in place. The tissue is also found around and between most body organs. In summary, areolar tissue is tough, yet flexible, and comprises membranes.


Which artery supplies the kidney with blood?

Blood Supply to the Kidneys - Anatomy Pictures and Information Home > Cardiovascular System > Cardiovascular System of the Lower Torso > Blood Supply to the Kidneys Blood Supply to the Kidneys Providing a constant supply of oxygenated blood to the kidneys is one of the most vital functions of the circulatory system. Despite their relatively small size, the kidneys receive about 20% of the heart’s blood output for filtration. The kidneys’ function is dependent on a constant blood supply, so interruptions in the blood flow to the kidneys may result in tissue death and loss of kidney function. Anatomy 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 Kidney Blood Filtration Full Blood Supply to the Kidneys Description [Continued from above] . . . In the abdomen, the renal arteries branch from the abdominal aorta inferior to the superior mesenteric artery and extend laterally toward the kidneys. Just before reaching the kidney, each renal artery divides into five segmental arteries, which provide blood to the various regions of the kidney. Each segmental artery enters the hilus of the kidney and divides into several interlobar arteries, which pass through the renal columns between the renal pyramids and carry blood toward the exterior of the kidney. At the junction between the renal cortex and renal medulla, the interlobar arteries form the arcuate arteries, which turn to follow the contours of the renal pyramids. From the arcuate arteries several branches, known as interlobular arteries, separate at right angles and extend through the renal cortex toward the exterior of the kidney. Each interlobular artery forms several afferent arterioles, which end in a bed of capillaries known as glomeruli where blood is filtered to form urine. Physiology Kidney function is highly dependent upon sufficient blood pressure in the glomeruli. The arteries and arterioles that provide blood flow to the kidneys must maintain sufficient blood flow to keep the tissues of the kidneys alive and also maintain sufficient blood pressure to allow wastes to be separated from the blood. Interruption of the blood flow through one of the segmental arteries or their branches results in kidney infarction, where kidney tissue dies and ceases to function. Interruption of the blood flow to the entire kidney results in kidney failure. While it is possible to survive with only one functional kidney, loss of both kidneys requires dialysis or a kidney transplant to filter wastes from the blood. Prepared by Tim Taylor, Anatomy and Physiology Instructor


How many ventricles are there in the human heart?

Your Heart & Circulatory System Your Heart & Circulatory System Tu corazón y sistema circulatorio Did you give your friends valentines and little heart-shaped candies on Valentine's Day? Do you ever cross your heart when making a promise that you really, really mean? Or turn on the radio to hear a guy singing about his broken heart? We see and hear about hearts everywhere. A long time ago, people even thought that their emotions came from their hearts, maybe because the heart beats faster when a person is scared or excited. Now we know that emotions come from the brain, and in this case, the brain tells the heart to speed up. So what's the heart up to, then? How does it keep busy? What does it look like? Let's find out. Working That Muscle Your heart is really a muscle. It's located a little to the left of the middle of your chest, and it's about the size of your fist. There are lots of muscles all over your body — in your arms, in your legs, in your back, even in your behind. But the heart muscle is special because of what it does. The heart sends blood around your body. The blood provides your body with the oxygen and nutrients it needs. It also carries away waste. Your heart is sort of like a pump, or two pumps in one. The right side of your heart receives blood from the body and pumps it to the lungs. The left side of the heart does the exact opposite: It receives blood from the lungs and pumps it out to the body.   We Got the Beat How does the heart beat? Before each beat, your heart fills with blood. Then its muscle contracts to squirt the blood along. When the heart contracts, it squeezes — try squeezing your hand into a fist. That's sort of like what your heart does so it can squirt out the blood. Your heart does this all day and all night, all the time. The heart is one hard worker! continue Heart Parts The heart is made up of four different blood-filled areas, and each of these areas is called a chamber. There are two chambers on each side of the heart. One chamber is on the top and one chamber is on the bottom. The two chambers on top are called the atria (say: AY-tree-uh). If you're talking only about one, call it an atrium. The atria are the chambers that fill with the blood returning to the heart from the body and lungs. The heart has a left atrium and a right atrium. The two chambers on the bottom are called the ventricles (say: VEN-trih-kulz). The heart has a left ventricle and a right ventricle. Their job is to squirt out the blood to the body and lungs. Running down the middle of the heart is a thick wall of muscle called the septum (say: SEP-tum). The septum's job is to separate the left side and the right side of the heart. The atria and ventricles work as a team — the atria fill with blood, then dump it into the ventricles. The ventricles then squeeze, pumping blood out of the heart. While the ventricles are squeezing, the atria refill and get ready for the next contraction. So when the blood gets pumped, how does it know which way to go? Well, your blood relies on four special valves inside the heart. A valve lets something in and keeps it there by closing — think of walking through a door. The door shuts behind you and keeps you from going backward. Two of the heart valves are the mitral (say: MY-trul) valve and the tricuspid (say: try-KUS-pid) valve. They let blood flow from the atria to the ventricles. The other two are called the aortic (say: ay-OR-tik) valve and pulmonary (say: PUL-muh-ner-ee) valve, and they're in charge of controlling the flow as the blood leaves the heart. These valves all work to keep the blood flowing forward. They open up to let the blood move ahead, then they close quickly to keep the blood from flowing backward. previous continue It's Great to Circulate You probably guessed that the blood just doesn't slosh around your body once it leaves the heart. It moves through many tubes called arteries and veins , which together are called blood vessels. These blood vessels are attached to the heart. The blood vessels that carry blood away from the heart are called arteries. The


What is the scientific name for the tube connecting the mouth with the stomach?

What tube connects the mouth and the stomach? | Reference.com What tube connects the mouth and the stomach? A: Quick Answer The tube that connects the mouth and the stomach is the esophagus, according to Dictionary.com. The esophagus is a muscular passage found in vertebrate and invertebrate animals. It's sometimes referred to as the "gullet." Full Answer WebMD explains that the esophagus is about 8 inches long and is located behind the heart and trachea, or windpipe, and in front of the spine. WebMD notes that the esophagus passes through the diaphragm just prior to entering the stomach. Muscles at the top of the esophagus are controlled consciously and are used during breathing, eating, vomiting, belching and in preventing food from entering the windpipe, according to WebMD. The muscles at the bottom of the esophagus are involuntary muscles, and they prevent acid and stomach contents from traveling back into the esophagus.


Which parts of the body are formed by the bones of the metatarsals and phalanges?

Bones of the Foot - Tarsals - Metatarsals - Phalanges - TeachMeAnatomy The human foot is a very complex and highly developed structure. The bones of the foot provide mechanical support for the soft tissues, helping the foot withstand the weight of the body. The bones of the foot can be divided into three categories: Tarsals – A set of seven irregularly shaped bones. They are situated proximally in the foot, in the ankle area. Metatarsals – These bones connect the phalanges to the tarsals. There are five in number – one for each digit. Phalanges – The bones of the toes. Each toe has three phalanges – a proximal, intermediate and distal (except the big toe, which only has two phalanges). Fig 1.0 – Overview of the bones of the human foot. Tarsals The tarsal bones of the foot are organised into three rows; proximal, intermediate and distal. Proximal Group The proximal tarsal bones are the talus and the calcaneus. They form the bony framework around the proximal ankle and heel area. The talus is the most superior of the tarsal bones. It has three articulations: Superiorly: Ankle joint – between the talus and the bones of the leg (the tibia and fibula). Inferiorly: Subtalar joint – between the talus and calcaneus. Anteriorly: Talonavicular joint – between the talus and the navicular. The main function of the talus is to transmit forces from the tibia to the heel bone (known as the calcaneus). Whilst numerous ligaments attach to the talus, it is not a site of muscle attachment or origin. Fig 1.1 – The tarsal bones of the foot. The calcaneus lies underneath the talus, and has two articulations: Superiorly: Subtalar joint – between the calcaneus and the talus. Anteriorly: Calcaneocuboid joint – between the calcaneus and the cuboid. It is thick and sturdy, acting to transmit forces from the talus to the ground. The posterior aspect of the calcaneus is marked by calcaneal tuberosity, to which the Achilles tendon attaches. Intermediate Group The intermediate row of tarsal bones contains one bone, the navicular (given its name because it is shaped like a boat). It articulates with the talus posteriorly, the cuneiform bones anteriorly, and the cuboid bone laterally. On the plantar surface of the navicular, there is a tuberosity for the attachment of the tibialis posterior tendon. Distal Group In the distal row, there are four tarsal bones – the cuboid and the three cuneiforms. These bones articulate with the metatarsals of the foot. The cuboid is the most lateral bone in the distal row, articulating with the calcaneus posteriorly, and two metatarsals anteriorly. As the name suggests, it is shaped like a cube. The inferior surface of the cuboid is marked by a groove for the fibularis longus muscle. The three cuneiforms (lateral, intermediate and medial) are wedge shaped bones. They articulate with the navicular posteriorly, and the metatarsals anteriorly. The shape of the bones helps form a transverse arch across the foot. Clinical Relevance: Fractures of the Talus and Calcaneus The talus and the calcaneus sit in the proximal part of the foot and ankle, and are involved in transmitting forces from the body to the ground. They are the most frequently fractured of all the tarsal bones. Talus Talar fractures occur in two places – the neck of the talus, or the body: Neck fractures are caused by excessive dorsiflexion of the foot. The neck of the talus is pushed against the tibia. In this type of fracture, the blood supply to the talus may be disturbed, leading to avascular necrosis of the bone. Body fractures usually occur from jumping from a height. In any fracture of the talus, the malleoli of the leg bones act to hold the fragments together, so there is little displacement of the fracture pieces. By Jojo (Own work) [CC-BY-SA-3.0], via Wikimedia Commons Fig 1.2 – X-ray of a calcaneal fracture. Calcaneus The calcaneus is often fractured in a ‘crush‘ type injury. The most common mechanism of damage is falling onto the heel from a height – the talus is driven into the calcaneus. The bone can break into several pieces – known as a comminuted


What is the fluid that lubricates and cushions the movable joints between the bones?

what is synovial fluid n wat is its rush? What is synovial fluid n wat is its stress? Answers: Synovial fluid is a thick, stringy fluid found contained by the cavities of synovial joint. With its egg-like consistency (synovial comes from Latin for "egg"), synovial fluid reduces friction between the articular cartilage and other tissues contained by joints to lubricate and cushion them during movement. Overview The inner membrane of synovial joint is called the synovial membrane, which secrete synovial fluid into the joint cavity. This fluid forms a sunken layer (approximately 50 micrometres) at the surface of cartilage, but also seep into the articular cartilage filling any unfilled space . The fluid within articular cartilage effectively serves as a synovial fluid reserve. During majority movements, the synovial fluid held within the cartilage is squeezed out routinely (so-called weeping lubrication) to maintain a band of fluid on the cartilage surface. more: http://en.wikipedia.org/wiki/synovial_fl... It is the fluid around closed joints, approaching the knees. It is very momentous to cushion the joint and keep hold of it lubricated and healthy. Joints that aren't roofed, like the spine, don't hold it, but are cushioned differently. Any of the sites below should have the answer you are looking for :-) http://adam.nearly.com/encyclopedia/19698... Synovial fluid is in adjectives of your freely movable joints. Elbow, Knee ,etc. It's rush is that it keeps your joint lubricated so that there is no friction. So not to mess up your bones. Synovial fluid is a viscous colourless fluid that bathe movable joints between the bones of vertebrates. It nourish and lubricates the cartilage at the end of respectively bone. The normal knees joint is surrounded by a membrane (the synovium) which produces a small amount of gooey fluid (synovial fluid). The synovial fluid helps to provide for the cartilage and keep it slippery. Synovial fluid is secreted by a membrane, the synovium, that links movably jointed bones. The same thoughtful of fluid is found in bursae, the membranous sac that buffer some joints, such as surrounded by the shoulder and hip region. Viscid lubricating fluid secreted by the membrane lining joint and tendon sheaths etc synovial common is a type of joint that allows free movements of bones..these joint r lined by a synovial membrane that secrete synovial fluid..Synovial fluid is normally a viscous (thick), straw colored substance that help in free movements of bones inwardly the joints..synovial fluid is tested surrounded by suspected joint pathologies..To gain the fluid for analysis, a sterile needle is inserted into the common space through skin that has be specially cleaned. Once in the pooled, fluid is aspirated through the needle into a sterile syringe.. It is consequently examined microscopically for cells (red and white cells), crystals (in the valise of gout), and bacteria. In assimilation, there may be a chemical analysis, and if infection is a concern, a example will be cultured to see if any bacteria grow. Abnormal cohesive fluid may look cloudy or abnormally gluey. Synovial fluid is a thick, stringy fluid found surrounded by the cavities of synovial joint. With its egg-like consistency (synovial comes from Latin for "egg"), synovial fluid reduces friction between the articular cartilage and other tissues contained by joints to lubricate and cushion them during movement. it is fluid present contained by joint contained by joint cavity.relief in lubrication of unified. synovial fluid is the fluid between your joints it keep the bones from rubbing together synovial fluid s actually fluid ie present surrounded by joints. it help as a lubricating agent for easy movement of joint without injuring the bones. synovial membrane forms the facing of the soft parts that enclose the cavity of a cohesive...the cavity has the synovial fluid it help in th lubrication of the joint.SYNOVITIS is the inflammation of the membrane lining the joint its a substance present between two joints & help in lubrication this is a flu


What is the oxygen-carrying protein found in the red blood cells of the body?

a Hemoglobins i Oxygen carrying proteins found in the red - FNH - 250 View Full                             Document ii. 2/3rds of irons are found here b. Myoglobins i. Oxygen-carrying proteins found in muscle cells (similar to hemoglobins) 4. What are 3 major functions of iron? a. b. Coenzyme for energy production c. Part of an antioxidant enzyme system that stabilizes free radicals 5. What are the forms we store iron as? Where is iron mainly stored? a. Ferritin and Hemosiderin b. Stored in: Liver, bone marrow, intestinal mucosal, bone marrow 6. How do the following affect absorption of iron from our diet: (a) iron status, (b) stomach acid, and (c) amount and type of iron in foods a. Iron status i. Those with lower iron status will have higher absorption of iron (see below) b. Stomach Acid i. An adequate pH of stomach is necessary for iron absorption 1. Ie. Too low pH = decrease iron absorption c. Amount and type of irons in food i. Amount 1. The more iron consumed, the lower the absorption ii. Types 1. Heme iron is more easily absorbed than non-heme iron (See below) 7. What affects iron status? a. Those that are iron deficient: pregnant women, menstruation 8. What is heme iron and what is non-heme iron? a. Heme Iron i. b. Non-heme Iron i. 9. Compare heme iron and non-heme iron in terms of their digestion and food sources a. Heme iron is more absorbable b. Food sources i. Heme Iron: 1. Animal-based foods like fish, meat, poultry ii. Non-heme iron: 1. Animal-based foods like fish, meat, poultry 2. Plant-based foods 10. Animal-based foods are better sources of iron (ie. More readily absorbable) b/c they contain more This is the end of the preview. Sign up to                   access the rest of the document. TERM Chapter 10- Nutrients Involved in Energy Metabolism.docx UBC FNH 250                     -                     Winter 2014 1. Vitamins and minerals do not provide us with energy. What do they do? a. Are coenz Chapter 10- Nutrients Involved in Energy Metabolism.docx


What are the chemicals produced by the endocrine glands to control body functions?

Hormones: the body’s chemical messengers | Visual Dictionary Subscribe Hormones: the body’s chemical messengers The human body secretes and circulates some 50 different hormones. A wide variety of these chemical substances are produced by endocrine cells, most of which are in glands. The hormones then enter the blood system to circulate throughout the body and activate target cells. The endocrine system, tightly linked to the nervous system , controls a large number of the body’s functions: metabolism, homeostasis, growth, sexual activity, and contraction of the smooth and cardiac muscles. The endocrine glands The endocrine system is composed of nine specialized glands (the pituitary, the thyroid, the four parathyroids, the two adrenals and the thymus) and a number of organs capable of producing hormones (including the pancreas , heart , kidneys , ovaries , testicles and intestines). The hypothalamus , which is not a gland but a nerve center, also plays a major role in the synthesis of hormonal factors. The endocrine system The hypothalamus and the pituitary gland: the control centers of the endocrine system Located under the thalamus, the hypothalamus is composed of several nuclei that control the autonomic nervous system and regulate hunger, thirst, body temperature and sleep. The hypothalamus also influences sexual behavior and controls the emotions of anger and fear. Closely linked to the pituitary gland , it acts as a coordinator between the nervous and endocrine systems. Generally considered the master endocrine gland, the pituitary secretes 10 different hormones. Some of these substances then act on the other endocrine glands. Unlike substances produced by the exocrine glands, which flow through ducts, the hormones are released directly into the space that surrounds them by secreting cells. The very high vascularization of endocrine glands enables hormones to spread throughout the blood system via the capillaries. Some of them circulate freely in the blood, while others must attach to carrier proteins to reach the target cells.


Where in the human body do you find the alveoli?

The role of Alveoli in the respiratory system Home / Training Zone / The Human Body / Respiratory System / Alveoli Alveoli Part of the respiratory system, these tiny alveoli have a key role in the movement of oxygen and carbon dioxide. Role in the respiratory system. The final branches of the respiratory tree, alveoli are where oxygen from the air enters your blood, and carbon dioxide from your body is expelled back into the air. How they work. Air enters the body through the nose or mouth, passes through the larynx, down the trachea, and into our lungs. Once it is in your lungs, air goes through a maze of smaller and smaller bronchial tubes until it reaches clusters of tiny sacs the alveoli. In appearance they are somewhat like bunches of grapes. Size and where they live. These alveoli are tiny, but your lungs are simply packed with them an estimated three hundred million per lung, all required to ensure that your body gets the oxygen it needs. Once it is in your lungs, the blood has to get into your blood. The alveoli are the primary gas exchange units of the lung. Quite simply, they are the point where the gas-blood barrier is thin enough to permit rapid gas exchange. To get into the blood, oxygen is diffused through the alveolar epithelium, a thin interstitial space, and the capillary endothelium. Role also has to be reversed. That is only half the process of course this process also has to work in reverse in order to allow CO2, a waste product carried by the blood, to be expelled back into the lungs, and thus out of the body when we exhale.


What name is given to the genetic make-up of an individual?

A genotype is the genetic make up of an individual Pearson - BIO - 1100 View Full                             Document Name ______Bennett_ ____ Page 2 of 7 Heredity 4. Explain Mendel’s “law” of “independent assortment”. When does it occur during cell division? Mendel’s law of independent assortment states that each pair of factors assorts independently of the other pairs and that all possible combinations of factors can occur in the gametes. (Mader and Windelspecht) This means that the genes from one trait separate independently from the genes of another trait allowing for multiple different outcomes. Independent assortment occurs in meiosis I, specifically in prophase I. 5. Explain Mendel’s “law” of “segregation”. Give an example. Mendel’s law of segregation states that each individual has two factors for each trait and that these factors separate during the formation of gametes. Each gamete then contains only one gene from each pair of genes. Fertilization then gives each new individual two genes for each trait. (Mader and Windelspecht) An example of the law of segregation is shown in the lab when the genes from a tall pea plant are combined with the genes of a dwarf pea plant resulting in the separation of the gametes and allowing for either a tall pea plant or dwarf pea plant as offspring. Genetics Problem Involving a Monohybrid Cross Possible Points 4 Points Deducted Add a row or column to the tables if necessary. 6. A plant that is heterozygous (Pp) for purple flowers is crossed with a plant that is also heterozygous (Pp) for purple flowers. What will be the genotypes and phenotypes of the F 1 generation? Type the possible gene combinations in the Punnett square and then type the genotype and phenotype ratios in the table below the Punnett square. P = purple flowers (dominant) p = white flowers (recessive) P p P PP Pp p Pp pp Genotypes Phenotypes of Flower Colors # of Each Phenotype (data taken from Punnett square) Ratios of Phenotypes PP Homozygous dominant 1 1:4 Purple flowers Purple flowers Name ______Bennett_ ____ Page 3 of 7 Heredity Pp Heterozygous 2 1:2 pp Homozygous recessive 1 1:4 Testcross Problem to Determine Unknown Genotypes Possible Points 4 Points Deducted Add a row or column to the tables if necessary. 7. This preview has intentionally blurred sections. Sign up to view the full version.


A bone is joined to a muscle by which structure?

Muscular and Skeletal Systems MUSCULAR AND SKELETAL SYSTEMS Interaction of the Two Systems | Links The single-celled protozoan ancestors of animals had their weight supported by water and were able to move by cilia or other simple organelles. The evolution of large and more complex organisms (animals) necessitated the development of support and locomotion systems. Animals use their muscular and skeletal systems for support, locomotion, and maintaining their shape. Types of Skeletal Systems | Back to Top Movement is a major characteristic of animals. This movement is a result of contraction of muscles. The skeleton helps transmit that movement. Skeletons are either a fluid-filled body cavity, exoskeletons , or internal skeletons. Hydrostatic skeletons consist of fluid-filled closed chambers. Internal pressures generated by muscle contractions cause movement as well as maintain the shape of the animals, such as the sea anemone and worms. The sea anemone has one set of longitudinal muscles in the outer layer of the body, and a layer of circular muscles in the inner layer of the body. The anemone can elongate or contract its body by contracting one or the other set of muscles. Structure and function of a hydrostatic skeleton. Images from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates ( www.sinauer.com ) and WH Freeman ( www.whfreeman.com ), used with permission. Exoskeletons are characteristic of the Phylum Arthropoda. Exoskeletons are hard segments that cover the muscles and visceral organs. Muscles for movement attach to the inner surface of the exoskeleton. Exoskeletons restrict the growth of the animal, thus it must shed its exoskeleton (or molt) to form a new one that has room for growth. The bulk and weight of the exoskeleton and associated mechanical problems limits the size animals can attain. Spiders use a combination of an exoskeleton for protection and fluid pressure for movement. Exoskeleton of an insect and its relation to the muscular system. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates ( www.sinauer.com ) and WH Freeman ( www.whfreeman.com ), used with permission. Vertebrates have developed an internal mineralized (in most cases) endoskeleton composed of bone and/or cartilage. Muscles are on the outside of the endoskeleton. Cartilage and bone are types of connective tissue . Sharks, and rays have skeletons composed entirely of cartilage; other vertebrates have an embryonic cartilage skeleton progressively replaced by bone as they mature and develop. Some areas of the human body, however, retain cartilage in the adult: in joints and flexible structures such as the ribs, trachea, nose and ears. The human endoskeleton. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates ( www.sinauer.com ) and WH Freeman ( www.whfreeman.com ), used with permission. Functions of Muscles and Bones | Back to Top The skeleton and muscles function together as the musculoskeletal system. This system (often treated as two separate systems, the muscular , and skeletal ) plays an important homeostatic role: allowing the animal to move to more favorable external conditions. Certain cells in the bones produce immune cells as well as important cellular components of the blood. Bone also helps regulate blood calcium levels, serving as a calcium sink. Rapid muscular contraction is important in generating internal heat, another homeostatic function. The Axial and Appendicular Skeletons | Back to Top The axial skeleton consists of the skull, vertebral column, and rib cage. The appendicular skeleton contains the bones of the appendages (limbs, wings, or flippers/fins), and the pectoral and pelvic girdles . The human skull, or cranium , has a number of individual bones tightly fitted together at immovable joints . At birth many of these joints are not completely sutured together as bone, leading to a number of "soft spots" or fontanels , which do not completely join until the age of 14-18 months. The vertebral column has 33 individ


Human Bones: Largest Bone in Body of Humans Information of the world Home » English » Pair of Words » Human Bones: Largest Bone in Body of Humans Bones are very important to give shape to the body, which raises the question which is being the largest bone in the human body. The size and the diameter of the bone depend on the health, height and sex of a person. The size of the biggest bone in human body of a tall man would be different from a man of an average size. Similarly the size and the thickness of different bones in men and women, whether of same height, would also be different. Keeping a single global size as standard, the details of the biggest and the longest bones are: Femur is the largest bone in body . It forms the upper part of human leg. Its average length in adult male is 50.50 centimeter. This bone is also found in mammals, reptiles and vertebrates i.e frog, lizards, amphibians etc. Femur is Latin word which means thigh hence it is also known as thigh bone. Tibia is the second largest bone in the human body and no doubt the strongest bone of human body because it bears the body weight of person. It forms the inner-lower part of human leg. The average length of tibia is 43.03 CM. Tibia is Latin word which means an ancient type of musical instrument. Shin bone and shank bone are other names of Tibia. Fibula (also known as Calf Bone) is located in the outer-lower part of human leg. Fibula is the third largest bone in the human body. Fibula along with Tibia forms the lower part of human leg as it is located on the lateral side of Tibia. It is relatively weak and thin as compared with Tibia. The average length of tibia is 40.50 CM. Humerus bone connects shoulder with elbow in human arm. It is a long bone which consists of three parts i.e. upper extremity of Humerus, body of Humerus and lower extremity of Humerus. Humerus forms the upper part of human arm and many important muscles are attached with it. The average length of tibia is 36.46 CM. Ulna forms the inner-lower part of human arm. This fore-arm bone along with radius completes the lower part of human arm. Its average length in 28.20 Cm. In simple words it connects elbow with hand. It is a long and narrow bone with many muscles attached with it. Radius is a long bone which forms the outer-lower part of human arm. It is on the lateral side of Ulna and its length is 26.42 cm. Radius is also found in some four-leg animals as lower part of forelimb. Like Ulna it connects hand with elbow. 7th rib is part of the 24 ribs found in a human body. The average length of 7th rib is 24.00 CM. Ribs are basically found in Vertebrates and they support the upper body of vertebrates. 8th rib: These long and curved bones are considered as the basic structural part of human body. 8th rib is the part of 12 pairs of ribs in human body. The average length of 8th rib is 23.00 CM. Innominate bone is also called hipbone or half pelvis. It is the 9th largest bone in human body. Its average length is 18.50 Cm. Innominate bone is either of the two bones that form the sides of the pelvis, consisting of three fused components, the ilium, ischium, and pubis Nontechnical name hipbone. Sternum is the tenth largest bone in human body and its average length is 17.00 Cm. It is also called breastbone and it is found in both males and females with the same length. Sternum is a long, flat bone located in the center of the chest, serving as a support for the collarbone and ribs.


Which of the retina's cells can distinguish between different wavelengths of light?

Molecular Expressions Microscopy Primer: Physics of Light and Color - Human Vision and Color Perception Movie Gallery Human Vision and Color Perception Human stereo color vision is a very complex process that is not completely understood, despite hundreds of years of intense study and modeling. Vision involves the nearly simultaneous interaction of the two eyes and the brain through a network of neurons, receptors, and other specialized cells. The first steps in this sensory process are the stimulation of light receptors in the eyes, conversion of the light stimuli or images into signals, and transmission of electrical signals containing the vision information from each eye to the brain through the optic nerves. This information is processed in several stages, ultimately reaching the visual cortices of the cerebrum. The human eye is equipped with a variety of optical components including the cornea, iris, pupil, aqueous and vitreous humors, a variable-focus lens, and the retina (as illustrated in Figure 1). Together, these elements work to form images of the objects that fall into the field of view for each eye. When an object is observed, it is first focused through the convex cornea and lens elements, forming an inverted image on the surface of the retina, a multi-layered membrane that contains millions of light-sensitive cells. In order to reach the retina, light rays focused by the cornea must successively traverse the aqueous humor (in the anterior chamber), the crystalline lens, the gelatinous vitreous body, and the vascular and neuronal layers of the retina before they reach the photosensitive outer segments of the cone and rod cells. These photosensory cells detect the image and translate it into a series of electrical signals for transmission to the brain. Despite some misconceptions due to the wide spectrum of terminology employed for describing eye anatomy, it is the cornea, not the lens, which is responsible for the major part of the total refractive power of the eye. Being smooth and clear as glass, yet as flexible and durable as plastic, the anterior, strongly curved, transparent part of the exterior wall of the eyeball allows the image-forming light rays to pass through to the interior. The cornea also protects the eye by providing a physical barrier that shields the inside of the eye from microorganisms, dust, fibers, chemical, and other harmful materials. Although much thinner in width than the crystalline lens, the cornea provides about 65 percent of the eye's refractive power. Most of the power to bend light resides near the center of the cornea, which is rounder and thinner than the peripheral portions of the tissue. As the window that controls the entry of light into the eye, the cornea (Figure 2) is essential to good vision and also acts as an ultraviolet light filter. The cornea removes some of the most damaging ultraviolet wavelengths present in sunlight, thereby further protecting the highly susceptible retina and crystalline lens from damage. If the cornea is curved too much, as in the case of nearsightedness, distant objects will appear as blurry images, because of imperfect light refraction to the retina. In a condition known as astigmatism, imperfections or irregularities in the cornea result in unequal refraction, which creates distortion of images projected onto the retina. Unlike most tissues of the body, the cornea does not contain blood vessels for nourishment or to protect it against infection. Even the smallest capillaries would interfere with the precise refraction process. The cornea receives its nourishment from tears and the aqueous humor, which fills the chambers behind the structure. The outer epithelial layer of the cornea is packed with thousands of small nerve endings, making the cornea extremely sensitive to pain when rubbed or scratched. Comprising about 10 percent of the tissue's thickness, the epithelial layer of the cornea blocks foreign matter from entering the eye while providing a smooth surface for oxygen and nutrient absorption. The central layer o


Which hormone causes male sexual development?

Male Hormones About Watch and Favorite Watch Watching this resources will notify you when proposed changes or new versions are created so you can keep track of improvements that have been made. Favorite Favoriting this resource allows you to save it in the “My Resources” tab of your account. There, you can easily access this resource later when you’re ready to customize it or assign it to your students. Male Hormones The onset of puberty is controlled by two major hormones: FSH initiates spermatogenesis and LH signals the release of testosterone. Learning Objective Explain the function of male hormones in reproduction Key Points The onset of puberty is signaled by high pulses of GnRH secreted by the hypothalamus ; this in turn signals the release of FSH and LH from the pituitary gland . FSH causes the Sertoli cells of the testes (which help nurse developing sperm cells) to begin the process of spermatogenesis in the testes. LH triggers the production of testosterone from the Leydig cells of the testis; testosterone causes the development of secondary sex characteristics in the male. As spermatogenesis and testosterone production increase, the Sertoli cells produce inhibin , which, together with rising levels of testosterone, inhibit the release of FSH and LH from the pituitary gland. Terms Male Hormones Puberty is a period of several years in which rapid physical growth and psychological changes occur, culminating in sexual maturity. The average onset of puberty is age 11 or 12 for boys. Some of the most significant parts of pubertal development involve distinctive physiological changes in individuals' height, weight, body composition, and circulatory and respiratory systems. These changes are largely influenced by hormonal activity. Hormones play an organizational role, priming the body to behave in a certain way once puberty begins, and an activational role, referring to changes in hormones during adolescence that trigger behavioral and physical changes. At the onset of puberty, the hypothalamus begins secreting high pulses of GnRH, or gonadotropin-releasing hormone . In response, the pituitary gland releases follicle stimulating hormone (FSH) and luteinizing hormone (LH) into the male system for the first time. FSH enters the testes, stimulating the Sertoli cells, which help to nourish the sperm cells that the testes produce, to begin facilitating spermatogenesis. LH also enters the testes, stimulating the interstitial cells, called Leydig cells, to make and release testosterone into the testes and the blood. Testosterone, the hormone responsible for the secondary sexual characteristics that develop in the male during adolescence, stimulates spermatogenesis, or the process of sperm production in the testes. Secondary sex characteristics include a deepening of the voice, the growth of facial, axillary, and pubic hair, and the beginnings of the sex drive. A negative feedback system occurs in the male with rising levels of testosterone acting on the hypothalamus and anterior pituitary to inhibit the release of GnRH, FSH, and LH . The Sertoli cells produce the hormone inhibin, which is released into the blood when the sperm count is too high. This inhibits the release of GnRH and FSH, which will cause spermatogenesis to slow down. If the sperm count reaches 20 million/ml, the Sertoli cells cease the release of inhibin, allowing the sperm count to increase.


Which part of the brain controls the heart rate?

What Parts of the Brain Control Respiration - Interactive Biology, with Leslie Samuel What Parts of the Brain Control Respiration Shares 22 The different parts of the brain with emphasis on the Medulla Oblongata First off, lets talk about what respiration is. In order for you to live, your body needs oxygen. Cell s use this oxygen in order for metabolism to take place and without it, you would have no energy. When you eat, that food is broken down and the process of respiration allows for you to convert that food into an energy form that can be used by your body. In addition to providing the body with Oxygen, it’s also responsible for getting rid of Carbon Dioxide, which is a waste product that is made in the body. Now that we have that covered, let’s talk about the involvement of the brain in this process. Your brain starts where the spinal cord enters the skull, and the first section that you encounter is called the Brain Stem. The brain stem contains the following structures: The medulla oblongata (I love that name) The Pons The Midbrain The medulla oblongata is involved in regulating many of the bodily processes that are controlled automatically like blood pressure, heart rate and yes, you guessed it . . . RESPIRATION. The way this works is relatively straightforward. The medulla oblongata basically detects carbon dioxide (CO2) and Oxygen (O2) levels in the bloodstream and determines what changes need to happen in the body. It can then send nerve impulses to muscle s in the heart and diaphragm , letting them know that they need to either step up their game, or slow down a bit. The reason I mentioned the heart is because the respiratory system is very much tied to  the circulatory system. What Happens During Exercise Lifting Weights 🙂 When you are exercising, you are using your muscle s in a significant way, and your body demands that you take in more oxygen so that it can be delivered to your muscle s. You circulatory and respiratory system needs to make sure that the oxygen is getting to the muscle s faster than when you are just chilling. Also, they need to make sure that the CO2 that is produced is taken away efficiently. In order for that process to happen efficiently, the medulla oblongata , after sensing what is happening, sends signals to the heart and the respiratory muscle s ( diaphragm and intercostal muscle s). You start breathing heavily (increased respiration) to get that O2 in and CO2 out. You heart starts beating faster because not only does the oxygen need to get into the body, but they need to be delivered to the muscle s. That gives you a pretty good idea of how the medulla oblongata controls the process of respiration. The main concept here is that there needs to be a good balance of things happening in your system in terms of respiration. If your cell s have what they need, your cell s are happy. If they are happy, your body is happy, and hopefully so are you. Questions or Comments? If you have any questions or comments about how this process works, or what I’ve written here, please post them below in the comments section. Infographic