organs structure and functions

blood vessels "two circuits"

"cardiovascular system", - the pulmonary circuit sends oxygen-depleted (deoxygenated) blood to the lungs to pick up oxygenand unload carbon dioxide. - the systemic circuit send oxygen-rich (oxygenated) blood and nutrients to all body cells and remove waste.

arteries

"cardiovascular system", are strong, elastic vessels adapted for carrying the blood away from the heart under high presure. these vessels subdivide into progressively thinner tubes and eventually give rise to finer branched arterioles. the wall of the artery consists of three distinct layers or tunics. the inner - tunica interna, the tunica media and tunica externa. an artery (different from veins) has thicker walls and thinner lumen, and has no valves.

capillaries

"cardiovascular system", are the smallest diameter blood vessels. they connect the smallest arterioles and the smallest venules. "exchange of substances ocur here"

heart

"cardiovascular system", pumps 7,000 liters of blood through the heart daily. is about 14 centimeters long and 9 centimeters wide. the heart is covered by the pericardial sac (pericardium). the heart has three layers; an outer epicardium or "visceral pericardium" (protects the heart by reducing friction), a middle myocardium (muscle for pumping action), and an inner endocardium (lines all heart chambers and covers structures. * PATH OF BLOOD THROUGH THE HEART -blood from systemic circuit - superior and inferior vena cava and coronary sinus - right atrium - tricuspid valve - right ventricle - pulmonary valve - pulmonary trunk - pulmonary arteries - alveolar capillaries (lungs) - pulmonary viens - left atrium - mitral (bicuspid) valve - left ventricle - aortic valve - aorta - blood to systemic ciruit. * HEART SOUNDS - the first part of the heart sound "lubb" occurs during the ventricle systole (contraction), when AV valves are closing. - the second part "dupp", ocurs during ventricle diastole (relaxtion), when the pulmonary and aortic valves are closing. * CONDUCTION SYSTEM - sinoatrial "SA" node (pacemacker, generate rhythmic contractions) - junctional fibers - atrioventricle "AV" node - AV bundle (bundle of his) - bundle branches - purkinje fibers

veins

"cardiovascular system", venules are microscopic vessels tha continue from the capillaries and merge to form veins. veins carry blood back to the atria, follow pathways that roughly parallel those of the arteries. veins (different from arteries) have valves, larger lumen and is under less pressure.

liver

"digestive system", "produces bile". The largest internal organ is the liver. The porta hepatis is where blood vessels and ducts enter or exit the liver. Kupffer cells are macrophages of the liver. The liver carries on many important metabolic activities. The liver plays a key role in carbohydrate metabolism by helping maintain the normal blood glucose concentrations. The liver plays a key role in lipid metabolism by oxidizing fatty acids, synthesizing lipoproteins, phospholipids, and cholesterol. The liver plays a key role in protein metabolism by deaminating amino acids, forming urea, synthesizing plasma proteins, and converting amino acids to other forms of amino acids. The liver stores glycogen, iron, and vitamins A (for a year), D, and B12. Liver cells help destroy worn out or damaged red blood cells. removes toxic substances (alcohol) from the blood. the liver serves as a blood reservior, storing 200 to 400 milliters of blood. The liver's role in digestion is to secrete bile. Bile is secreted by hepatic cells and contains water, bile salts, bile pigments, cholesterol, and electrolytes. Hepatic cells use cholesterol to make bile salts. Bile pigments are products of the breakdown of hemoglobin. Jaundice results from an accumulation of bile pigments in the blood stream. Functions of bile salts are to aid digestive enzymes by emulsifying fats, and facilitate the absorption of fat soluble vitamins. Emulsification is the breaking of fat globules into smaller droplets.

gallbladder

"digestive system", "stores bile". The gallbladder is located inferior to the liver. The cystic duct is the duct of the gallbladder and opens into the common bile duct. The common bile duct is formed from the cystic duct and common hepatic duct and opens into duodenum. Gallstones form when bile is too concentrated, hepatic cells secrete too much cholesterol, or if the gallbladder is inflamed. Cholecystokinin triggers the gallbladder to release bile and is released in response to presence of lipids and proteins in the small intestine.

salivary Glands

"digestive system", Salivary glands secrete saliva. The functions of saliva are to moisten food, bind food together, and begin the chemical digestion of carbohydrates. The three pairs of major salivary glands are parotid glands, submandibular glands, and sublingual glands.Two cell types of salivary glands are serous and mucous. Serous cells produce watery fluid that contains amylase. Mucous cells produce mucus. Amylase digests carbohydrates. Salivary glands are innervated by both sympathetic and parasympathetic nerves. Sympathetic fibers stimulate the glands to secrete a small volume of viscous saliva. Parasympathetic fibers stimulate the glands to secrete a large volume of watery saliva.

anus

"digestive system", The anal canal is the continuation of the rectum. Anal columns are folds of mucous membranes in the anal canal. The anus is the opening of the anal canal. Two sphincters of the anus are the internal and external. The internal anal sphincter is composed of smooth muscle (involuntary). The external anal sphincter is composed of skeletal muscle (voluntary).

Esophagus

"digestive system", The esophagus is a passageway for food. The esophagus propels food (bolus) from the pharynx to the stomach by peristalsis (wavelike contractions). The esophagus descends through the thoracic cavity. The esophageal hiatus is an opening in the diaphragm. Mucous glands are scattered throughout the submucosa of the esophagus. The lower esophageal sphincter (cardiac sphincter) is located where the esophagus and stomach join and functions to prevent regurgitation of food.

pancreas

"digestive system", The pancreas is located close to the duodenum posterior to the parietal peritoneum. The pancreatic ducts extend the hepatopancreatic ampulla and empties into the duodenum. Pancreatic juice contains many enzymes and bicarbonate ions. The function of pancreatic amylase is to digest carbohydrates. The function of pancreatic lipase is to digest lipids. The functions of trypsin, chymotrypsin, and carboxypeptidase are to digest proteins. Zymogen granules are granules that store pancreatic enzymes. The function of trypsinogen is to be converted to trypsin. The functions of nucleases are to digest nucleic acids. Parasympathetic fibers cause the pancreas to release pancreatic juice. The function of secretin is to stimulate the pancreas to release pancreatic juice with a high concentration of bicarbonate ions. The release of cholecystokinin is triggered by the presence of chyme in the small intestine. The action of cholecystokinin on the pancreas is to release pancreatic juice that has a high concentration of digestive enzymes.

pharynx

"digestive system", The pharynx is a cavity posterior to the nasal and oral cavities. The pharynx and esophagus function in swallowing. The three divisions of the pharynx are the nasopharynx, oropharynx, and laryngopharynx. The nasopharynx provides a passageway for air. The oropharynx is a passageway for food and air. laryngopharynx is a passageway to the esophagus.

small intestine

"digestive system", The small intestine extends from the pyloric sphincter to the large intestine. The small intestine receives secretions from the pancreas, gallbladder, and liver. The functions of the small intestine are to complete digestion, absorption of nutrients, and movement of solid wastes to the large intestine. 95% of digestion is in the small intestine. The three parts of the small intestine are duodenum, jejunum, and ileum. . Mesentery is double-layered fold of peritoneum and supports the blood vessels, nerves, and lymphatic vessels that supply the intestinal wall. The greater omentum is a double fold of peritoneal membrane that drapes like an apron from the stomach, over the transverses colon, and the small intestine. The functions of the omentum are to prevent the spread of infections in the peritoneal cavity. Intestinal villi are tiny projections of the mucosa of the small intestine. The functions of villi are to increase the surface area of the lining of the small intestine. The enzymes embedded in the membranes of epithelial cells of the small intestine are peptidase, sucrase, maltase, lactase, lipase, and enterokinase. The most important absorbing organ is the small intestine. Carbohydrate digestion begins in the mouth and is completed in the small intestine. Segmentation is the major mixing movement of the small intestine.

tongue

"digestive system", The tongue is located in the floor of the oral cavity. Mucous membranes cover the tongue. The frenulum of the tongue is a membranous fold that anchors the tongue to the floor of the mouth. The body of the tongue is composed of skeletal muscles. Muscles of the tongue function to mix food particles and push food to the back of the throat during swallowing (deglutition). Papillae of the tongue are rough projections on the surface of the tongue. Functions of papillae are to provide friction to push food to back of oral cavity for swallowing and to house taste buds. The root of the tongue is anchored to the hyoid bone. Lingual tonsils are located on the root of the tongue.

large intestine

"digestive system", has little or no digestive function. The functions of the large intestine are to form feces, eliminate solid wastes, and to absorb remaining water and electrolytes from chyme.The parts of the large intestine are cecum, colon, rectum, and anal canal. Mucus secretion into the large intestine is controlled by mechanical stimulation and parasympathetic impulses.The functions of mucus in the large intestine are to form and store feces, eliminate feces, and absorb remaining water and electrolytes from chyme. Chyme entering the large intestine contains few nutrients, nondigestible materials, water, electrolytes, mucus, and bacteria. The large intestine can absorb water and electrolytes. The functions of intestinal flora are to synthesize some vitamins and to produce gas. Mass movements (peristalic waves) are produced when a large section of the intestinal wall constricts vigorously (2-3 times a day).The actions of the defecation reflex are to increase internal abdominal pressure and the forcing of feces into the rectum. Peristaltic waves are triggered and anal sphincters relax. A person can inhibit defecation by contracting the external anal sphincter. Feces are composed of materials that were not digested or absorbed, some water, electrolytes, mucus, and bacteria.

stomach

"digestive system", is a J-shaped, pouchlike organ, about 25-30centimeters long, which hangs inferior to the diaphram in the upper left portion of the abdominal cavity and holds about 1liter. the stomach receives food from the esophagus, mixes it with gastric juices, initiates the digestion of proteins, carries on limited absorbtion, and move food into the small intestine. of the digestive enzymes in gastric juice, pepsin is by far the most important. the chief cells secrete pepsin as an inactive, nonerosive enzyme precursor called pepsinogen. when pepsinogen contacts hydrochloric acid from parietal cells, however, it breaks down rapidly, forming pepsin. pepsin begins digestion of nearly all types of protein into into polypeptides (amino acids). the stomach absorbs only some water, certain salts, lipid soluble drugs, and alcohol (also absorbed in small intestine). stomach contrations push chyme (a mix of food particles and gastric juice) a little at a time into the small intestine. these stomach contration wave (segmentaion)push most of the chyme backward into the stomach, mixing it further. the lower esophageal sphincter (cardiac sphincter) prevents reflux of the stomach contents into the esophagus.

rectum

"digestive system", stores and regulates elimination of feces.

mouth

"digestive system", the first part of alimentary canal. The functions of the mouth are to receive food and to begin digestion. Mastication is chewing. mechanical breakdown of food and begins chemical digestion of carbohydrates.

parathyroid glands

"endocrine system", are on the posterior surface of the thyroid gland (4 of them, 2 superior and 2 inferior). they secrete a hormone that regulates the concentration of calcium and phosphate ions in the blood. parathyroid hormone increases blood calcium ion concentration and decreases blood phosphate ion concentration through the actions in the bones, kidneys and intestines.

pancreas

"endocrine system", consist of two major types of secretory tissue. dual function as an exocrine gland that secretes digestive juice through a duct and an endocrine gland that releases hormones into body fluids. "a negitive feeback system". hormomes from pancreas are; 1). glucagon - is a protein that stimulates the liver to break down glycogen (a polysaccharide, or carbhydrate) into glucose(a monosaccharide or single sugar) and to convert noncarbohydrates, such as amino acids into glucose. glucagon also stimulates breakdown of fats into fatty acids and glycerol (building block for fat). 2). insulin - a protein, and its main effect is exactly opposite that of glucagon. insulin stimulates the liver to form glycogen from glucose and inhibits conversion of noncarbohydrates into glucose. insulin decreases the concentration of blood glucose (sugar), transports amino acids into cells, increases protein synthesis and stimulates adipose cells to store fat. 3). somatostatin - helps regulate glucose metabolism (release of energy by cells) by inhibiting secretions of glucogon and insulin.

hypothalamus "is in control"

"endocrine system", controls the pituitary glands release of tropic horomes, which stimulate other endocrine glands to release hormones. the hypothalamus constantly recieves information about the internal enviroment from neural connections and cerebrospinal fluid, made possible by it location near the thalamus and the third ventricle. is a part of the negitive feeback system. -hypothalamus-anterior pituitary-peripheral endocrine glands-

pineal gland

"endocrine system", is a small, oval structure deep between the cerebral hemispheres, where it attaches to the upper portionof the thalamus near the roof of the third ventricle. the pineal gland secretes a hormone melatonin that is synthesized from seritonin. varying patterns of light and dark outside the body controls the glands activities. melatonin secretions is part of the regulation of circadian rhythms, which are patterns of repeat acitiity with the cycles of day and night, such as being awake or asleep.

thyroid gland

"endocrine system", is a vascular structure that consist of two large lateral lobes connected by a broad isthmus (over trachea). the thyroid lies just below the larynx. this gland is specialized to remove iodine from the blood. the thyroid gland produces three important hormones; 1). thyroxine - increases rate of energy released from carbohydrates, increases rate of protein synthesis, accelerates growth, and stimulates activity in the nervous system. 2). triiodothyronine - same as thyroxine, but five times more potent. 3). calcitonin - lowers blood calcium and phosphate ion concentrations, increase the rate at which calcium and phosphate ions are deposited in bones, and increases the excretion of calcium by the kidneys.

pituitary gland "the master gland"

"endocrine system", is at the base of the brain, its about one centimeter in diameter. it is attached to the hypothalamus by the pituitary stalk, or infundibulum, and lies in the sella turcica of the sphenoid bone. the pituitary gland consist of 2 lobes, the anterior and posterior lobes. the anterior lobe secretes an number of hormones, including growth, thyroid-stimulating, and prolactin hormones. the posterior lobe does not synthesize any horomes but it secretes antidiuretic hormones and oxytocin. the hypothalamus in the brain controls most of the pituitary glands activities.

adrenal glands

"endocrine system", is closely associated with the kidneys. the cells of the adrenal medulla produce, store and secrete two closely related hormones, epinephrine ("adrenalin", affects muscles). epinephrine is systhesized from norepinephrine. the medullary secretion function together with the sympathetic divions of the autonomic nervous system in preparing the body for energy-expending action - "fight or flight". the adrenal cortex prduces more than thirty different steroids (corticosteriods) that are vital. without these secretion from the adrenal cortex, a person will die within weeks.

thymus

"endocrine system", lies in the mediastinum between the lungs, is large in young children but shrinks with age. this gland secretes a group of hormones called thymosins, that affects the production and differentiation of certain white blood cells (T- lymphocytes). the thymus plays an inportant role in immunity.

kidneys

"endocrine system", secrete erythropoietin that stimulates red blood cell production.

ovaries and testes

"endocrine system", testes produce testosterone and the ovaries produce estrogens and progesterone.

skin

"integumentary system", the largest organ in the body by weight. is strong yet flexible cover for our bodies for protection, is vital in maintaining homeostasis. it houses sensory receptors, helps regulate body temperature, synthesizes vitamin D, contains immune system cells, and secretes small amounts of waste. made up of the epidermis, dermis, and hypodermis. the layers of the epideris (composed of stratified squamous epithelium) are, from outer most to inner: stratum corneum, lucidum, granulosum, spinosum, and basale-the deepest.

tonsils

"lymphatic system", are parially encapsulated lymph nodes.

thymus

"lymphatic system", is a soft, bilobed structure enclosed in a connective tissue capsule. it is in the mediastinum, anterior to the aortic arch. the thymus shrinks after puberty. the lobules of of the thymus house many lymphocytes that develop from progentior from a stem cell) cells in the bone marrow. most of these cells (thymocytes) are inactived, but some mature into T-lymphocytes (T-cell), "T for thymus derived", which leave the thymus and provide immunity. epithelial cells in the thymus secretes protein hormones called thymosins, which stimulates maturation of T-lymphocytes.

spleen

"lymphatic system", is the largest lymphatic organ. the spleen resembles a large lymph node and has a hilum. unlike a lymph node the spaces in the chambers of the spleen are filled with blood. the red pulp, which fills the remaining spaces of the lobules, surrounds the venous sinuses. this pulp contains abundant red blood cells, which impart its color, plus many lymphocytes and macrphages. lymphpcytes of the spleen help defend the body against infection. the spleen filters blood much as the lymph nodes filter lymph.

lymph

"lymphatic system", lymph is essentially fluid that has that has entered a lymphatic capillary by osmosis (colloid osmotic pressure). thus, lymph formation depends upon tissue fluid formation. lymph transports foreign particles, such as bacteria and viruses, to lymph nodes. lymph formation prevents the accumulation of excess tissue fluid, or edema. the hydrostatic pressure of tissue fluid drives lymph into lymphatic capillaries. muscular activity largely influences the movement of lymph throught the lymphatic vessels. lymph like venous blood, is under relatively low hydrostatic pressure. lymph flow peaks during physical exercise, due to the action of skeletal muscles and pressure changes associated with breathing. * LYMPHATIC PATHWAY - lymphatic capillary - afferent lymphatic vessels (4) - lymph node - efferent lymphatic vessel (1) - lymphatic truck - collecting duct - subclavian vein.

lymph nodes

"lymphatic system", they contain many lymphocytes and macrophages that fight invading pathogens. lymph nodes vary in size and shape but are usually less than 2.5 centimeters long and bean shaped. blood vessels and nerves join a lymph node through the indented region of the node, called the hilum. masses of lymphocytes (B cells) and macrophages in the cortex, called lymph nodules (lymph follicles), are functional units of the lymph node. * LOCATION OF LYMPH NODES 1). cervical region - mandible and neck - drain the skin and face, and the tissue of the nasal cavity and pharynx. 2). axillary region - armpit - drain the upper limbs, the wall of the thorax, the mammary glands (breast), and upper wall of the abdomen. 3). supratrochlear region - medial elbow - they are often enlarged in children in response to infection acquired through cuts and scrapes of the hands. 4). inguinal region - groin - receive lymph from the loweer limbs, external genitalia, and lower abdominal wall. 5). pelvic cavity - here lymph nodes primariliy follow the illiac blood vessels. receives lymph from the lymphatic vessels of the pelvic viiscera. 6). abdominal cavity - these lymph nodes form chains along the main branches of the mesenteric arteries and abdominal aorta. receive lymph from the abdominal viscera. 7). thoracic cavity - these lymph nodes are in the mediastinum and along the trachea and bronchi. they receive lymph from the thoracic viscera and from the internal wall of the thorax.

muscles

"muscular system", muscles provide all movements, talking, walking and breathing. muscles are organs composed of specialized cells that use the chemical energy stored in nutrients to exert a pulling force on structures to which they are attached. also provide muscle tone, propel body fluids and food, generate the heart beat, and distribute heat. - skeletal - voluntary. - cardiac - involuntary - self exciting and rhythmic contractions. - smooth - involuntary - slower and more gradual.

brainstem

"nervous system", the brainstem connects the brain to the spinal cord. 1). the midbrain contains the centers for certain visual reflexes, such as those that move the eyes to view somehting as the head turns, auditory reflexes. communicates with cerebellum and spinal cord to provide reflexes that maintain posture. 2). the pons relays impulses to the medulla oblongata, and cerebellum. 3). the medulla oblongoata contains the cardiac center, vasomotor centers - vasoconstriction and vasodilation, respiratory center, nonvital reflexes - coughing, sneezing, swallowing and vomiting. also contains vital reflex centers, injuries to this part of the brainstem can be fatal.

spinal cord

"nervous system", the is a slender column of nervous tissue that is continuous with the brain and extends downward through the vertebral canal and starts at the foramen magnum and ends at the second lumbar vertebrae. the spinal cord consists of thirty one segments, each of which gives rise to a pair of spinal nerves. the spinal cord tapers to a structure called the conus medullaris (is at the 4th lumbar vertebrea), then tapers even more into the filum terminale, and then extends thorough the sacrum called the cauda equina or "horse tail". the spinal cord has two main functions,1). is a center for spinal reflexes. 2). is a conduit for nerve impulses to and from the brain.

nerves

"nervous system"," impulses to and from brain and spinal cord" * Cranial nerves 1). olfactory - sensory - sense of smell. 2). optic - sensory - sense of vision. 3). oculomotor - primarily motor - raise eyelids, move eyes, adjust the amount of light entering the eyes, and focus the lenses. 4). trochlear - primarily motor - moves the eyes. 5). trigeminal - mixed - 3 branches - ophthalmic division - surface of the eyes, tear glands, scalp, forehead, and upper eyelids. - maxillary division - upper teeth, upper gums, upper lips, lining of the palate, and skin of the face. - mandibular division - scalp, skin of the jaw, lower teeth, lower gum, lower lip. impulses to muscles for mastication and floor of the mouth. 6). abducens - primarily motor - move eyes 7). facial - mixed - taste receptors of tongue, facial expressions, tear and salivary glands. 8). vestibulocochlear - sensory - 2 branches - vestibular branch - sense of equilibrium. - cochlear branch - sense of hearing. 9). glossopharyngeal - mixed - pharynx, tonsils, posterior tongue, and carotid arteries. mucsles of the pharynx used in swalling. 10). vagus - mixed - muscles of speech and swalling, visera of the thorax and abdomen, pharynx, larynx, esophagus. 11). accessory - primarily motor - 2 branches - cranial branch - soft palate, pharynx, and larynx - spinal branch - muscles of the neck and back. 12). hypoglossal - primarily motor - muscles that move the tongue. * spinal nerves - cervical - thoracic - lumbar - sacral - coccygeal * note plexus are present for limbs - cervical plexus - C1-C4 - brachial plexus - C5-T1 - intercostal nerves - T2-T11 - lumbosacral plexus - T12-S5

the brain

"nervous system". the brain is the largest and most complex part of the nervous system. it oversees many aspects of physiology, such as sensation, perception, movement, personality, and thinking. it issues motor commands to skeletal muscles and carries on higher mental functions, such as memory and reasoning. contains centers that coordinate muscular movements. in general the the brain oversees the function of the entire body. the brain includes the two cerebral hemispheres, the diencephalon contains the thalamus and hypothalamus, and the brainstem which attaches the brain to the brain to the spinal cord. the cerebellum coordinates movement and body position. the frontal lobes carry on higher intellectual process for concentrating, planning, complex problems, and knowing right from wrong. the pariental lobes deal with fealing of temperture, touch, pressure, pain involving the skin, understanding speech, and use of words to express thoughts and fealings. the temporal lobes are responsible for hearing, interprets sensory experiences, remember visual scenes, music and other complex sensory patterns. the occipital lobes are responsible for vision, and combine visual images with other sensory experiences.

mammary glands "breasts"

"reproductive system", . The mammary glands are located in the subcutaneous tissue of the anterior thorax within breasts. Breasts are hemispherical elevations. The breasts overlie the pectoralis major muscles and extend from the second to the sixth ribs and from the sternum to the axillae. A nipple is a projection located near the tip of each breast. The areola is a circular area of pigmented skin that surrounds a nipple.A mammary gland is composed of fifteen to twenty irregularly shaped lobules. Each lobule of a mammary gland contains glands drained by alveolar ducts which drain into a nipple. Suspensory ligaments are dense strands of connective tissue that extend inward from the dermis of the breast to help support the breast. Ovarian hormones stimulate development of breasts in the female. As a result of ovarian hormones, alveolar glands and ducts enlarge, and fat is deposited so that each breast becomes surrounded by adipose tissue.

seminal vesicle

"reproductive system", A seminal vesicle is a convoluted, saclike structure attached to the vas deferens near the base of the urinary bladder. The secretions of the seminal vesicle are slightly alkaline and contain fructose and prostaglandins. The functions of the secretions of the seminal vesicle are to help regulate the pH of the tubular contents as sperm cells travel the outside, to provide energy to sperm cells, and to stimulate muscular contractions within the female reproductive organs, aiding the movement of sperm. As sperm move through the vas deferens into the ejaculatory duct the contents of the seminal vesicles empty into the ejaculatory ducts.

epididymis

"reproductive system", Each epididymis is a tightly coiled, threadlike tube and is connected to ducts within a testis. An epididymis is located on the posterior and superior surface of a testis. The inner lining of the epididymis is composed of pseudostratified columnar cells that secrete glycogen and other substances that support stored sperm cells and promote their maturation. When immature sperm cells reach the epididymis, they are nonmotile.

ductus "vas" deferens

"reproductive system", Each vas deferens is a muscular tube that is lined with pseudostratified columnar epithelium. Each vas deferens is located at the lower end of the epididymis and passes upward along the medial side of a testis, is become part of the spermatic cord. Each vas deferens ends behind the urinary bladder. The ampulla of a vas deferens is a dilation at the terminal end of a vas deferens. The ejaculatory duct is formed by the union of a vas deferens and the duct of a seminal vesicle. The ejaculatory duct passes through the prostate gland and empties into the urethra.

labia minora

"reproductive system", Labia minora are flattened longitudinal folds between the labia majora. Labia minora are composed of connective tissue richly supplied with blood vessels and stratified squamous epithelium.

ovaries

"reproductive system", Ovaries are solid, ovoid structures and are located in shallow depressions on each side in the lateral wall of the pelvic cavity. The functions of the organs of the female reproductive are to produce and maintain female sex cells, to transport eggs to the site of fertilization, to provide a favorable environment for a developing offspring, to move the offspring to the outside, and to produce female sex hormones. The primary sex organs of the female reproductive system are the ovaries. The accessory organs of the female reproductive system are internal reproductive organs (except the ovaries) and external reproductive organs.

semen

"reproductive system", Semen is the fluid the urethra conveys to the outside during ejaculation and consists of sperm cells and secretions from seminal vesicles, the prostate gland, and bulbourethral glands. The average number of sperm cells in semen is about 120 million per milliliter. Sperm cells cannot fertilize an egg cell until they enter the female reproductive tract. Capacitation is weakening of acrosomal membranes that give the sperm the ability to release acrosomal enzymes. Sperm cells live up to three days in the female reproductive tract.

bulbourethral glands

"reproductive system", The bulbourethral glands are two small structures that are located inferior to the prostate gland lateral to the membranous urethra. The bulbourethral glands are composed of many tubes. The bulbourethral glands secrete a mucous like fluid which functions to lubricate the end of the penis in preparation for sexual intercourse.

clitoris

"reproductive system", The clitoris is a small projection and is located at the anterior end of the vulva between the labia minora. The clitoris is composed of two columns of erectile tissue and dense connective tissue. The crura of the clitoris are where the corpora cavernosa diverge and attach to the pubic arch. The glans of the clitoris is the anterior end of the clitoris that contains erectile tissue and is richly supplied with sensory nerve fibers.

penis

"reproductive system", The functions of the penis are to convey urine and semen through the urethra to the outside. Erection is the enlarging and stiffening of the penis and enables it to be inserted into the vagina during sexual intercourse.The body of the penis is composed of three columns of erectile tissue, connective tissue, and skin. Corpora cavernosa is a paired column of erectile tissue dorsally located. Corpus spongiosum is a single column of erectile tissue ventrally located. A tunica albuginea is tough capsule that surrounds each column of erectile tissue. The glans penis is the enlargement of the corpus spongiosum at its distal end. The external urethral orifice is the urethral opening. The prepuce is a loose fold of skin just posterior to the glans and extends anteriorly to cover its sheath. Circumcision is removal of the prepuce. The crura of the penis are the lateral diverging of corpora cavernosa that is attached to the pubic arch. The bulb of the penis is the enlargement of the corpus spongiosum between the crura.

uterus

"reproductive system", The functions of the uterus are to receive the embryo and sustain its development. The broad ligament is a structure that attaches to the ovaries and uterine tubes, and extends from the lateral walls of the uterus to the pelvic walls and floor, creating a drape across the top of the pelvic wall. The round ligament is a flattened band of tissue within the broad ligament that connects the upper end of the uterus to the anterior pelvic wall. The uterus is located medially within the anterior portion of the pelvic cavity, superior to the vagina, and is usually bent forward over the urinary bladder. In the nonpregnant state, the size of the uterus is about 7 cm long and 5 cm wide. The body of the uterus is the upper two-thirds of the uterus. The fundus of the uterus is the dome shaped top of the uterus. The cervix is the lower one-third of the uterus. The three layers of the wall of the uterus are the inner endometrium, middle myometrium, and the outer perimetrium. The endometrium is the inner mucosal layer lining the uterine cavity. The myometrium is a very thick, muscular layer, largely composed of bundles of smooth muscle fibers in longitudinal, circular, and spiral patterns and is interlaced with connective tissues. The perimetrium is an outer serosal layer of the uterus.

labia majora

"reproductive system", The labia majora enclose the other external reproductive organs. The labia majora are composed of rounded folds of adipose tissue and a thin layer of smooth muscle, covered by skin. The skin of the labia majora contains hairs, sweat glands, and sebaceous glands. The pudendal cleft is the cleft that separates the labia majora and includes the urethral and vaginal openings. The mons pubis is a rounded elevation of adipose tissue that overlies the symphysis pubis.

prostate gland

"reproductive system", The prostate gland is a chestnut shaped structure that surrounds the proximal portion of the urethra. The prostate gland is composed of many branched tubular glands enclosed in connective tissue. The ducts of the prostate gland open into the urethra. The secretions of the prostate gland include a thin, milky, alkaline fluid. The functions of the secretions of the prostate gland are to neutralize sperm cell-containing fluid, to enhance motility of sperm, and to neutralize the acidic environment of the vagina.

scrotum

"reproductive system", The scrotum consists of skin, subcutaneous tissue, and smooth muscle fibers and is located outside the abdominal wall posterior to the penis. The function of the dartos muscle is to wrinkle the skin of the scrotum during cold conditions. The scrotum is divided into two chambers. Each chamber of the scrotum is lined with a serous membrane, which functions to help the testes move freely within the scrotum.

testes

"reproductive system", The testes are ovoid structures. The testes are suspended by spermatic cords. The testes are contained within the scrotum. The functions of the organs of the male reproductive system are to produce and maintain the male sex cells, to transport sex cells to the female reproductive tract, and to secrete male sex hormones. The primary organs of the male reproductive system are testes in which sperm cells and male sex hormones are produced. The accessory organs of the male reproductive system are all reproductive organs that are not the testes.

vagina

"reproductive system", The vagina is located inferior to the uterus, posterior to the urinary bladder, and anterior to the rectum. The functions of the vagina are to convey uterine contractions, to receive the erect penis during sexual intercourse, and to provide an open channel for the offspring during birth. Fornices of the vagina are the recesses between the vaginal wall and the cervix. The hymen of the vagina is a thin membrane that partially covers the vaginal orifice. The three layers of the vaginal wall are mucosal layer, muscular layer, and fibrous layer. The mucosal layer is the inner vaginal lining composed of stratified squamous epithelium. The muscular layer is the middle vaginal layer composed of smooth muscle fibers. The fibrous layer is the outer vaginal layer composed of dense connective tissue interlaced with elastic fibers.

vestibule

"reproductive system", The vestibule contains the vaginal opening, urethral opening, and the openings vestibular glands. Vestibular glands are located on either side of the vaginal opening and function to produce a mucous-like fluid for lubrication of the vaginal orifice during sexual intercourse. Vestibular bulbs are masses of erectile tissue beneath the mucosa of the vestibule on either side.

fallopian tubes "Uterine Tubes"

"reproductive system", Uterine tubes are suspended by portions of the broad ligament. Uterine tubes are located between ovaries and the uterus. The infundibulum of a uterine tube is an expansion of a uterine tube near the ovary. Fimbriae are branched extensions on the margins of an infundibulum. The walls of uterine tubes are composed of an inner mucosal layer, a middle muscular layer, and an outer covering of peritoneum. The cilia of the uterine tubes function to transport an egg down uterine tubes. The egg moves down a uterine tube due to ciliary action and peristaltic contractions of the uterine tube's muscular layer.

sinuses

"respiratory system", Sinuses are air-filled spaces located within the maxillary, frontal, ethmoid, and sphenoid bones of the skull. The functions of sinuses are to reduce the weight of the skull and to serve as resonant chambers that affect the quality of the voice.

bronchial Tree

"respiratory system", The bronchial tree consists of branched airways leading from the trachea to the microscopic air sacs in the lungs. Primary bronchi are the first branches of the trachea (right primary brochi is more likely of an obstrucion). The carina is a ridge of cartilage that separates the primary bronchi. Each bronchus, accompanied by blood vessels and nerves, enters its respective lung. * BRANCHES OF THE BRONCHIAL TREE - Primary bronchi - secondary (lobar) bronchi - tertiary (segmenta) bronchi - intralobular bronchioles - terminal bronchioles - respiratory broncioles - alveolar ducts - alveolar sacs - alveoli. The branches of the bronchial tree function to filter incoming air and distribute it to the alveoli in all parts of the lungs. The alveoli function to provide a large surface area of thin epithelial cells through which gas exchanges can occur.

Larynx

"respiratory system", The larynx is an enlargement in the airway superior to the trachea and inferior to the pharynx. The functions of the larynx are to move air into the trachea, prevent foreign objects from entering the trachea, and to house vocal cords. The larynx is composed of a framework of muscles and cartilages bound by elastic tissue. The cartilages of the larynx are thyroid, cricoid, and epiglottic. The thyroid cartilage is located just superior to the thyroid gland. The cricoid cartilage is located inferior to the thyroid cartilage. The functions of the epiglottis are to prevent foods and liquids from entering the air passages and to allow air to pass into the trachea. The arytenoids and corniculate cartilages are attachments sites for muscles that help regulate tension on the vocal cords during speech and aid in closing the larynx during swallowing.False vocal cords are located inside the larynx and are composed of muscle tissue and connective tissue with a covering of mucous membrane. The function of the false vocal cords is to help close the larynx during swallowing. The true vocal cords are located inferior to the false vocal cords and are composed of elastic fibers. The functions of the true vocal cords are to produce sounds of speech. A higher pitch of the voice is produced by increasing tension on true vocal cords and a lower pitch is produced by decreasing the tension on the cords. The loudness of a vocal sound depends on upon the force of air passing over the vocal cords. The glottis is the opening between vocal cords. The mucous membrane that lines the larynx continues to filter incoming air by entrapping particles and moving them toward the pharynx by ciliary action.

lungs

"respiratory system", The lungs are cone shaped and located in the thoracic cavity. The right and left lungs are separated by the heart and the mediastinum and enclosed by the diaphragm and thoracic cage. Tubular structures enter the lung on its medial surface through a region called the hilum. Visceral pleura are serous membranes attached to the surfaces of the lungs. Parietal pleura are serous membranes that line the thoracic cavity. The pleural cavity is the potential space between the visceral pleura and parietal pleura. The functions of serous fluid in the pleural cavity are to lubricate serous membranes, reduce friction during lung movements, and hold pleural membranes together. The lobes of the right lung are superior, middle, and inferior. The lobes of the left lung are superior and inferior. Lobules of the lungs are divisions of lung lobes. Breathing or ventilation is the movement of air from outside the body into the bronchial tree and alveoli, followed by a reversal of this air movement. Inspiration is inhalation and Expiration is exhalation.

nasal Cavity

"respiratory system", The nasal cavity is a hollow space behind the nose. The nasal septum is a structure that divides the nasal cavity into left and right halves. The nasal cavity is separated from the cranial cavity by the cribiform plate of the ethmoid bone and from the oral cavity by the hard palate. Nasal conchae (turbinate bones) are located on the lateral walls of the nasal cavity and divide the nasal cavity into superior, inferior, and middle meatuses. Nasal conchae function to support the mucous membranes that line the nasal cavity and to increase the surface area of the nasal cavity. The lining of the upper portion of the nasal cavity contains olfactory receptors. Most of the nasal cavity conducts air to and from the nasopharynx. The mucous membrane lining the nasal cavity contains pseudostratified ciliated epithelium that is rich in mucous-secreting goblet cells. The functions of the mucous membrane of the nasal cavity are to warm the air, to moisten the air, and to trap small particles entering the nasal cavity. Cilia of the nasal cavity function to move mucous and any entrapped particles toward the pharynx.

nose

"respiratory system", The nose is supported internally by muscle, bone, and cartilage. Nostrils are openings through which air can enter and leave the nasal cavity. Internal hairs of nostrils prevent entry of large particles carried in air.

pharynx

"respiratory system", The pharynx is located posterior to the oral cavity and between the nasal cavity and the larynx. Functions of the pharynx are to move food into the esophagus, to move air into the larynx, and to aid in the production of sound.

trachea

"respiratory system", The trachea is a flexible cylindrical tube and is located anterior to the esophagus in the thoracic cavity. The trachea splits into right and left bronchi. The inner wall of the trachea is lined with a ciliated mucous membrane that contains many goblet cells. The mucous membrane of the trachea functions to filter incoming air and to move entrapped particles upward into the pharynx where the mucous can be swallowed. The wall of the trachea is composed of C shaped pieces of hyaline cartilage, smooth muscle, and connective tissues. The cartilaginous rings of the trachea prevent the trachea from collapsing and blocking the airway. The soft tissues that complete the rings in the back of the trachea allow the esophagus to expand as food moves through it on the way to the stomach. A blocked trachea causes asphyxiation. A tracheostomy is the production of a temporary hole in the trachea.

ligaments

"skeletal system", bundles of strong, tough collagenous fibers that reinforce the joint capsule and help bind the articular ends of the bones. helps prevent excessive movement at the joint. it is relatively inelastic, and tightens when the joint is stressed. "cord or sheet of connective tissue binding two or more bones at a joints".

bones

"skeletal system", supports and protects softer tissue, provides points of attachment for muscles, houses blood producing cells (in bone marrow), for movement with muscles, and stores inorganic salts. bone classification: long bones-have long axes and expanded ends, short bones-cubelike (carpals and tarsals), flat bones-platelike (ribs, scapulae and bones of the skull), irregular bones (vertebrae, and facial bones), and sesamoid bones-round (patella). also includes ligaments.

kidneys

"urinary system", A kidney is reddish brown in color and bean shaped and is enclosed by a tough, fibrous capsule. The functions of the kidneys are to remove substances from blood, form urine, and to regulate certain metabolic processes. The main functions of the kidneys are to regulate the volume, composition, and pH of body fluids and to remove metabolic wastes from the blood and excrete them to the outside. Erythropoietin functions to regulate the production of red blood cells. Renin regulates blood pressure. Hemodialysis is an artificial means of removing substances from blood that would normally be excreted in urine. Renal arteries arise from the abdominal aorta. At rest, the renal arteries contain 15% to 30% of the total cardiac output. Functional units of the kidneys are called nephrons. Each nephron consists of a renal corpuscle and renal tubules. A renal corpuscle consists of a glomerulus and glomerular capsule. A glomerulus is cluster of capillaries. The juxtaglomerular apparatus is important in regulating the secretion of renin.

urethra

"urinary system", The urethra conveys urine from the bladder to the outside. Urethral glands are located in the urethral wall and function to secrete mucus into the urethral canal. The external urethral sphincter (justdistal to prostate) is located as part of the urogenital diaphragm and functions to voluntarily control urination. The three parts of the male urethra are prostatic, membranous, and penile. Micturition is urination reflex. The muscles that contract during micturition are the destrusor muscle, abdominal wall muscles, pelvic floor muscles, and the diaphragm. The micturition reflex center is located in the sacral portion of the spinal cord. The urgency to urinate occurs when the bladder wall distends as it fills with urine. Micturition is usually under voluntary control because the external urethral sphincter is under voluntary control.

urinary bladder

"urinary system", The urinary bladder is located within the pelvic cavity, posterior to the symphysis pubis, and inferior to the parietal peritoneum. The trigone of the bladder consists of the opening of the urethra and the two openings of the ureters. The neck of the bladder is a funnel shaped extension of the bladder that contains the opening into the urethra. The four layers of the wall of the bladder are an inner mucous coat, a submucous coat, a muscular coat, and an outer serous coat.The mucous coat is composed of transitional epithelial cells. The submucosa consists of connective tissue and elastic fibers. The muscular coat is composed of smooth muscle fibers. The detrusor muscle is the collection of smooth muscle fibers in the wall of the urinary bladder and works with the PNS to stimulate a reflex to pass urine. The internal urethral sphincter is located in the neck of the bladder and functions to prevent the bladder from emptying until the pressure within the bladder increases to a certain level. The serous coat is composed of the parietal peritoneum.

ureters

"urinary system", Ureters are located posterior to the parietal peritoneum and parallel to the vertebral column. In the pelvic cavity, they course forward and medially to join the bladder. The three layers of the wall of a ureter are an inner mucous coat, a middle muscular coat, and an outer fibrous coat. Urine is moved through ureters by peristaltic waves. A renal calculus is a kidney stone. The effects of ureter obstruction are to stimulate constriction of the renal arterioles and to reduce urine output.

joints

~CLASSIFICATION OF JOINTS~ FIBROUS (connective tissue holding together with many collages fibers) -syndesmosis- bones are bound by sheets or bundles of dense connective tissue, and is flexible. .ex: bwteen tibia and fibula. -suture- are only between flat bones of the skull. (babies- shoft spot are fontels). -gomphosis-formed by the union of a cone shaped bony process in a bony socket. ex: roots of teeth in the mandile and maxilla bones. CARTILAGINOUS (hyaline or fibrocartilage) -synchondrosis-bands of hyaline that unites bones. ex: epiphyseal plate or growth plate, when ossifiactaion is completed growth stops, usually before 25. then becomes a synostosis. -symphysis-springy fibrocartilage, with thin layer of hyaline. ex: symphysis pubis in the pelvis or intervertebral disc between the vertibrea, they absorb shocks and helps equalize pressure. SYNOVIAL JOINTS (articular cartilage, ligaments, synovial membrane-capsule, synovial fluid-in synovial cavity and secrete by the synovial membrane, is viscous fluid, menisci-compartments in the joints to help distribute body wieght, and bursae-cushion and aid movement of tendons that glide over bone or other tendins. -ball-and-socket joint or spheroidal joint-wide range of motion on all planes (head of femur in the acetabulum of the hip and the head of the humerous and the glenoid cavity of the scapula. -condylar joint or ellipsoidal joint-variety of movements in different planes, not rotational movement, (between metacarpals and phalanges) -plane joints or griding joints- back and forth and twisting movements (carpals, tarsals, ribs 2-7 connected to the sternum, and vertebrae) -hinge joints- (the elbow and phalanges) -pivot joint or trochoid joints- (head radius and ulna, and the dens of the axis and the atlas vertibrae) -sadle joint or sellar joint- (betweem the carpal and metacarpal of the thumb) -knee joint- is the largest and most complex synovial joint, is a modified hinge joint, beteen the femur and the tibia are condylar, and the joint between the femur and the patella is a plane joints.