bio 181 department final for Dr. Arfeen's class (warning: has a lot of information!!!)

4.Describe the mechanics of both restful (quiet) and forceful (heavy)breathing.

Inhalation (always active) and exhalation (passive or active); 2 types of inhalation = quet and forced; 2 types of exhalation = quiet and forced

2.Identify the innate (non-specific) body defenses

-Responds immediately regardless of invader -Provided by mechanical barriers (intact skin, mucous membranes) and cells and their chemical products -Help protect body from invading pathogens and reduces job of adaptive/specific defense system which takes over after

5.Describe the epithelium in each area of the digestive system

Epithelial Tissue Biological tissue is a collection of inter-connected cells that perform a similar function within an organism. The Stomach is mainly composed of the epithelial, muscular and connective tissue. The simple columnar epithelial cell is made up of the microvili (increases the surface area of the cell), cytoplasm, nucleus, basal liminia (lines outer surfaces of cell membrane) and has loose connective tissue. Connective Tissue The Digestive System is a group of organs working together to convert food into energy and basic nutrients needed to support the body. The digestive system is made up of the mouth, esophagus, stomach, small intestine, large intestine, liver, pancreas, gall bladder, rectum and anus. All these organs are uniquely structured to perform the specialized function of converting food into energy. The Muscular Tissue mixes stomach contents and forces contents towards the lower intestine. Simple columnar epithelial cells in the Stomach The connective tissues primary purpose in the stomach is to separate the mucosa from the smooth muscle layer of the stomach wall. Together with the epithelial tissue, it makes up the mucosa, which secretes gastric acid to aid in digestion. It also absorbs nutrients from the stomach.

5.Describe the process of fertilization

Fertilization is the process by which the nucleus of a sperm (a male reproductive cell) fuses (combines) with the nucleus of an egg (a female reproductive cell; also called an ovum). Biologically speaking, fertilization (or conception) is the beginning of human development.1 Fertilization normally occurs within several hours of ovulation2 (some authors report up to 24 hours) when a man's sperm, or spermatozoon, combines with a woman's egg, or secondary oocyte, inside a woman's uterine tube (usually in the outer third of the uterine tube called the ampulla). Fertilization begins with the spermatozoon contacting the cells surrounding the oocyte and ends with the mixing of the 23 male and 23 female chromosomes.5 [More about fertilization] The result is a single-cell embryo called a zygote, meaning "yoked or joined together,"and it is the first cell of the human body. The zygote, like the oocyte, is encased by its protective covering, the zona pellucida, [More about the zona] 8 and contains unique chromosomes with the entire genetic blueprint of a new individual. Chromosomes contain tightly packed, tightly coiled molecules called DNA. [More about DNA] Amazingly, DNA contains all the instructions needed for this single-cell embryo to develop into an adult. The First Cell Division The final steps in zygote formation include replication of the male and female DNA and the alignment of chromosomes in preparation for the first cell division through mitosis (mi-to'sis).10 The chromosomes assume a formation called a cleavage spindle, which is a phase of mitosis. As the 2 sets of chromosomes migrate to opposite ends of the zygote, a crease begins to form along the equator marking the impending line of division.11 (Fig xx) The zygote or single-cell embryo completes the first cell division approximately 24 to 30 hours after fertilization.12 The process of repeated cell division is called cleavage.13 Mitosis - Dynamic Division, Magnificent Multiplication After the first cell division, these 2 daughter cells are called blastomeres and proceed with mitosis independently. Two cells become four, four become eight, and so on as these and subsequent daughter cells divide repeatedly.36 The first days of cell division do not increase the size of the embryo because the blastomeres become smaller as their numbers increase. Additionally, after the third round of cell division, the cells become more tightly packed in a process called compaction. As compaction proceeds, the cells of the embryo divide into 2 populations with distinct destinies. (described below) Subsequent cell divisions occur take about 8 hours to reach completion. Replication of DNA over that time period requires an assembly rate exceeding 208,000 nucleotides per second.Amazingly, DNA replication is accomplished with an average of only 1 error per billion (109) nucleotides. Early Pregnancy Factor As early as 24 to 48 hours after fertilization begins, pregnancy can be confirmed by detecting a hormone called "early pregnancy factor" or EPF in the mother's blood40 (The test for this hormone, however, is not widely available). This substance helps prevent the mother's immune system from rejecting the soon-to-be-implanted embryo and allows pregnancy to proceed. Embryo Transport in the Uterine Tube As cell division proceeds, the embryo is on the move. The uterine tube steers the embryo toward the uterus by cilia motion of epithelial cells lining the uterine tube wall and continued mild muscle contractions.42 The cells of the corona radiata disappear within about 2 days while the zona persists in protecting the embryo and preventing premature implantation in the uterine tube.

4.Identify the great vessels of the heart and describe blood flow through these vessels

Five great vessels enter and leave the heart: the superior and inferior vena cava, the pulmonary artery, the pulmonary vein, and the aorta. The superior vena cava and inferior vena cava are veins that return deoxygenated blood from circulation in the body and empty into the right atrium. The pulmonary artery carries deoxygenated blood from the right ventricle into the lungs for oxygenation. The pulmonary veins carry oxygenated blood from the lungs into the left atrium to be returned to systemic circulation. The aorta is the largest artery in the body. It carries oxygenated blood from the left ventricle of the heart into systemic circulation. The Venae Cavae The superior vena cava and inferior vena cava are collectively called the venae cavae. They are the veins that return deoxygenated blood from the body into the heart, emptying into the right atrium. The venae cavae are not separated from the right atrium by valves. The venae cavae, along with the aorta, form the systemic circuit . The Systemic Circuit The venae cavae and the aorta form the systemic circuit, which circulates blood to the head, extremities and abdomen. The superior vena cava is a large, short vein that carries deoxygenated blood from the upper half of the body to the right atrium. The left and right brachiocephalic veins carry blood from the upper limbs, head, and neck, then converge with the azygous vein carrying blood from the thoracic area to form the superior vena cava. The superior vena cava begins above the heart. The inferior vena cava is the largest vein in the body and carries deoxygenated blood from the lower half of the body into the heart. The left and right common iliac veins carry converge to form the inferior vena cava. The inferior vena cava begins posterior to the abdominal cavity and travels to the heart next to the abdominal aorta. The Pulmonary Vessels It is through the pulmonary circuit that blood travels from the heart to the lungs for oxygenation, then back to the heart for delivery to the systemic circulation. The pulmonary arteries carry deoxygenated blood from the right ventricle into the lungs for oxygenation. These are the only arteries that carry deoxygenated blood. The main pulmonary artery begins at the base of the right ventricle as a short, wide vessel. It then branches into the left and right pulmonary arteries to which deliver deoxygenated blood to the respective lungs. Pulmonary circuit Diagram of pulmonary circulation. Oxygen-rich blood is shown in red; oxygen-depleted blood in blue. The pulmonary veins carry oxygenated blood from the lungs to the left atrium of the heart. These veins are unusual in that they carry oxygenated blood, since most veins carry deoxygenated blood. Four pulmonary veins enter the left atrium. The right pulmonary veins pass behind the right atrium and superior vena cava while the left pass in front of the descending thoracic aorta. The Aorta The aorta is the largest of the arteries in the systemic circuit. Blood is pumped from the left ventricle through the aorta into systemic circulation. The aorta is an elastic artery and is able to expand and contract in response to blood pressure and volume. When the left ventricle contracts to force blood through the aortic valve into the aorta, the aorta expands. This expansion, or stretching of the aorta, provides potential energy to help maintain blood pressure during diastole, when the aorta passively contracts. Mean arterial blood pressure is highest in the aorta and diminishes through circulation. The difference in pressure between the aorta and right atrium accounts for blood flow in the circulation. The aortic arch contains baroreceptors (pressure sensors) and chemoreceptors (chemical sensors) that relay information concerning blood pressure, blood pH, and carbon dioxide levels to the medulla oblongata of the brain. This information is processed by the brain and the autonomic nervous system mediates the homeostatic responses. The aorta is often described in five segments and extends from the left ventricle down to the abdomen, where it bifurcates into two smaller arteries, known as the common iliac arteries, for systemic distribution. The five segments are: The ascending aorta, describing the section between the heart and the arch of aorta The arch of aorta, describing the peak of the aorta The descending aorta, describing the section from the arch of aorta to the point where it divides into the common iliac arteries The thoracic aorta, describing the part of the descending aorta above the diaphragm The abdominal aorta, describing the part of the descending aorta below the diaphragm

3.Describe the process of glomerular filtration

Glomerular filtration is the first step in urine formation and constitutes the basic physiologic function of the kidneys. Blood plasma enters the afferent arteriole and flows into the glomerulus . The Bowman's capsule (also called the glomerular capsule) surrounds the glomerulus and is composed of visceral (simple squamous epithelial cells) (inner) and parietal (simple squamous epithelial cells) (outer) layers. The visceral layer lies just beneath the thickened glomerular basement membrane and is made of podocytes which send foot processes over the length of the glomerulus. Foot processes interdigitate with one another forming filtration slits that, in contrast to those in the glomerular endothelium, are spanned by diaphragms. The size of the filtration slits restricts the passage of large molecules (eg, albumin) and cells (eg, red blood cells and platelets). In addition, foot processes have a negatively-charged coat, the glycocalyx, that limits the filtration of negatively-charged molecules, such as albumin. This action is called electrostatic repulsion. Blood in the glomerulus has both filterable blood components and non-filterable blood components. Filterable blood components move toward the inside of the glomerulus while non-filterable blood components bypass the filtration process by exiting through the efferent arteriole. Filterable blood components such as water, nitrogenous waste, and nutrients form the glomerular filtrate. Non-filterable blood components such as blood cells and platelets remain in the blood and exit the glomeruli via the efferent arteriole. The glomerular filtrate is not the same consistency as urine, as much of it is reabsorbed into the blood as the filtrate passes through the tubules of the nephron.

1.Describe Glomerular Filtration Rate (GFR)

Glomerular filtration rate (GFR) is a test used to check how well the kidneys are working. Specifically, it estimates how much blood passes through the glomeruli each minute. Glomeruli are the tiny filters in the kidneys that filter waste from the blood.

5.Describe the hormones produced by the pituitary, pineal gland thyroid gland , pancreas, parathyroid glands, ovaries, and testes

Hormones are biochemical messengers that regulate physiological events in living organisms. More than 100 hormones have been identified in humans. Hormones are secreted by endocrine (ductless) glands such as the hypothalamus, the pituitary gland, the pineal gland, the thyroid, the parathyroid, the thymus, the adrenals, the pancreas, the ovaries, and the testes. Hormones are secreted directly into the blood stream, where they travel to target tissues and modulate digestion, growth, maturation, reproduction, and homeostasis. Hormones do not fall into any one chemical category, but most are either protein molecules or steroid molecules. These biological managers keep the body systems functioning over the long term and help maintain health. The study of hormones is called endocrinology. Hypothalamus Most hormones are released into the bloodstream by a single gland. Testosterone is an exception, because it is secreted by both the adrenal glands and by the testes. The major site that keeps track of hormone levels is the hypothalamus. A number of hormones are secreted by the hypothalamus, and they stimulate or inhibit the secretion of hormones at other sites. When the hypothalamus detects high levels of a hormone, it reacts to inhibit further production. When low levels of a hormone are detected, the hypothalamus reacts to stimulate hormone production or secretion. The body handles the hormone estrogen differently. Each month, the Graafian follicle in the ovary releases increasing amounts of estrogen into the bloodstream as the egg develops. When estrogen levels rise to a certain point, the pituitary gland secretes luteinizing hormone (LH), which triggers the egg's release into the oviduct. The major hormones secreted by the hypothalamus are corticotropin releasing hormone (CRH), thyrotropin releasing hormone (TRH), follicle stimulating hormone releasing hormone (FSHRH), luteinizing hormone releasing hormone (LHRH), and growth hormone releasing hormone (GHRH). CRH targets the adrenal glands. It triggers the adrenals to release adrenocorticotropic hormone (ACTH). ACTH functions to synthesize and release corticosteroids. TRH targets the thyroid where it functions to synthesize and release the thyroid hormones T3 and T4. FSH targets the ovaries and the testes where it enables the maturation of the ovum and of spermatozoa. LHRH also targets the ovaries and the testes, helping to promote ovulation and increase progesterone synthesis and release. GHRH targets the anterior pituitary to release growth hormone to most body tissues, increase protein synthesis, and increase blood glucose. The hypothalamus also secretes other important hormones such as prolactin inhibiting hormone (PIH), prolactin releasing hormone (PRH), and melanocyte inhibiting hormone (MIH). PIH targets the anterior pituitary to inhibit milk production at the mammary gland, and PRH has the opposite effect. MIH targets skin pigment cells (melanocytes) to regulate pigmentation. Pituitary gland The pituitary has long been called the master gland because of the vast extent of its activity. It lies deep in the brain just behind the nose, and is divided into anterior and posterior regions. Both anti-diuretic hormone (ADH) and oxytocin are synthesized in the hypothalamus before moving to the posterior pituitary prior to secretion. ADH targets the collecting tubules of the kidneys, increasing their permeability to and retention of water. Lack of ADH leads to a condition called diabetes insipidus characterized by excessive urination. Oxytocin targets the uterus and the mammary glands in the breasts. Oxytocin also triggers labor contractions prior to birth and functions in the ejection of milk. The drug pitocin is a synthetic form of oxytocin and is used medically to induce labor. The anterior pituitary (AP) secretes a number of hormones, including growth hormone (GH), ACTH, TSH, prolactin, LH, and FSH. GH controls cellular growth, protein synthesis, and elevation of blood glucose concentration. ACTH controls secretion of some hormones by the adrenal cortex (mainly cortisol). TSH controls thyroid hormone secretion in the thyroid. In males, prolactin enhances testosterone production; in females, it initiates and maintains LH to promote milk secretion from the mammary glands. In females, FSH initiates ova development and induces ovarian estrogen secretion. In males, FSH stimulates sperm production in the testes. LH stimulates ovulation and formation of the corpus luteum, which produces progesteronein females, whereas LH stimulates interstitial cells in males to produce testosterone. Thyroid gland The thyroid lies under the larynx and synthesizes two hormones, thyroxine and tri-iodothyronine. This gland takes up iodine from the blood and has the highest iodine level in the body. The iodine is incorporated into the thyroid hormones. Thyroxine has four iodine atoms and is called T4. Tri-iodothyronine has three iodine atoms and is called T3. Both T3 and T4 function to increase the metabolic rate of several cells and tissues. The brain, testes, lungs, and spleen are not affected by thyroid hormones, however. T3 and T4 indirectly increase blood glucose levels as well as the insulin-promoted uptake of glucose by fat cells. Their release is modulated by TRH-RH from the hypothalamus. When temperature drops, a metabolic increase is triggered by TSH. Chronic stress seems to reduce TSH secretion which, in turn, decreases T3 and T4 output. Depressed T3 and T4 production is the trademark of hypothyroidism. If it occurs in young children, this decreased activity can cause physical and mental retardation. In adults, it creates sluggishness—mentally and physically—and is characterized further by weight gain, poor hair growth, and a swollen neck. Excessive T3 and T4 cause sweating, nervousness, weight loss, and fatigue. The thyroid also secretes calcitonin, which serves to reduce blood calcium levels. Calcitonin's role is particularly significant in children whose bones are still forming. Parathyroid glands The parathyroid glands are attached to the bottom of the thyroid gland. They secrete the polypeptide parathyroid hormone (PTH), which plays a crucial role in monitoring blood calcium and phosphate levels. Calcium is a critical element for the human body. Even though the majority of calcium is in bone, it is also used by muscles, including cardiac muscle, for contractions, and by nerves in the release of neurotransmitters. Calcium is a powerful messenger in the immune response of inflammation and blood clotting. Both PTH and calcitonin regulate calcium levels in the kidneys, the gut, bone, and blood. PTH deficiency can be due to autoimmune diseases or to inherited parathyroid gland problems. Low PTH capabilities cause depressed blood calcium levels and neuromuscular problems. Very low PTH can lead to tetany or muscle spasms. Excess PTH can lead to weakened bones because it causes too much calcium to be drawn from the bones and to be excreted in the urine. Abnormalities of bone mineral deposits can lead to a number of conditions, including osteoporosis and rickets. Osteoporosis can be due to dietary insufficiencies of calcium, phosphate, or vitamin C. The end result is a loss of bone mass. Rickets is usually caused by a vitamin D deficiency and results in lower rates of bone formation in children. These examples show the importance of a balanced, nutritious diet for healthy development. Adrenal glands The two adrenal glands sit one on top of each kidney. Both adrenals have two distinct regions. The outer region (the medulla) produces adrenaline and noradrenaline and is under the control of the sympathetic nervous system. The inner region (the cortex) produces a number of steroid hormones. The cortical steroid hormones are derived from cholesterol and include mineralocorticoids (mainly aldosterone), glucocorticoids (mainly cortisol), and gonadocorticoids. Aldosterone and cortisol are the major human steroids in the cortex. However, testosterone and estrogen are secreted by adults (both male and female) at very low levels. Aldosterone plays an important role in regulating body fluids. It increases blood levels of sodium and water and lowers blood potassium levels. Cortisol secretion is stimulated by physical trauma, exposure to cold temperatures, burns, heavy exercise, and anxiety. Cortisol targets the liver, skeletal muscle, and adipose tissue, and its overall effect is to provide amino acids and glucose to meet synthesis and energy requirements for metabolism and during periods of stress. Because of its anti-inflammatory action, cortisol is used clinically to reduce swelling. Excessive cortisol secretion leads to Cushing's syndrome, which is characterized by weak bones, obesity, and a tendency to bruise. Cortisol deficiency can lead to Addison's disease, which has the symptoms of fatigue, low blood sodium levels, low blood pressure, and excess skin pigmentation. The adrenal medullary hormones are epinephrine (adrenaline) and nor-epinephrine (nor-adrenaline). Both of these hormones serve to supplement and prolong the "fight or flight" response initiated in the nervous system. This response includes increased heart rate, peripheral blood vessel constriction, sweating, spleen contraction, glycogen conversion to glucose, dilation of bronchial tubes, decreased digestive activity, and low urine output. Pancreas The pancreas secretes the hormones insulin, glucagon, and somatostatin, also known as growth hormone inhibiting hormone (GHIH). Insulin and glucagon have reciprocal roles. Insulin promotes the storage of glucose, fatty acids, and amino acids, while glucagon stimulates mobilization of these constituents from storage into the blood. Insulin release is triggered by high blood glucose levels. It lowers blood sugar levels and inhibits the release of glucose by the liver in order to keep blood levels down. Insulin excess can cause hypoglycemia leading to convulsions or coma, and insufficient levels of insulin can cause diabetes mellitus, which can be fatal if left untreated. Diabetes mellitus is the most common endocrine disorder. Glucagon secretion is stimulated by decreased blood glucose levels, infection, cortisol, exercise, and large protein meals. Among other activities, it facilitates glucose release into the blood. Excess glucagon can result from tumors of the pancreatic alpha cells, and a mild diabetes seems to result. Some cases of uncontrolled diabetes are also characterized by high glucagon levels, suggesting that low blood insulin levels are not necessarily the only cause in diabetes cases. Female hormones The female reproductive hormones arise from the hypothalamus, the anterior pituitary, and the ovaries. Although detectable amounts of the steroid hormone estrogen are present during fetal development, at puberty estrogen levels rise to initiate secondary sexual characteristics. Gonadotropin releasing hormone (GRH) is released by the hypothalamus to stimulate pituitary release of LH and FSH, which propagate egg development in the ovaries. Eggs (ova) exist at various stages of development, with the maturation of one ovum taking about 28 days. The ova are contained within follicles that are support organs for ova maturation. About 450 of a female's 150,000 germ cells mature to leave the ovary. The hormones secreted by the ovary include estrogen, progesterone, and small amounts of testosterone. As an ovum matures, rising estrogen levels stimulate additional LH and FSH release from the pituitary. Prior to ovulation, estrogen levels drop, and LH and FSH surge to cause the ovum to be released into the fallopian tube. The cells of the burst follicle begin to secrete progesterone and some estrogen. These hormones trigger thickening of the uterine lining, the endometrium, to prepare it for implantation should fertilization occur. The high progesterone and estrogen levels prevent LH and FSH from further secretion—thus hindering another ovum from developing. If fertilization does not occur, eight days after ovulation the endometrium deteriorates, resulting in menstruation. The falling estrogen and progesterone levels that follow trigger LH and FSH, starting the cycle all over again. In addition to its major roles in the menstrual cycle, estrogen has a protective effect on bone loss, which can lead to osteoporosis. Hormones related to pregnancy include human chorionic gonadotrophin (HCG), estrogen, human chorionic somatomammotrophin (HCS), and relaxin. HCG is released by the early embryo to signal implantation. Estrogen and HCS are secreted by the placenta. As birth nears, relaxin is secreted by the ovaries to relax the pelvic area in preparation for labor. Male hormones Male reproductive hormones come from the hypothalamus, the anterior pituitary, and the testes. As in females, GRH is released from the hypothalamus, which stimulates LH and FSH release from the pituitary. Testosterone levels are quite low until puberty. At puberty, rising levels of testosterone stimulate male reproductive development including secondary characteristics. LH stimulates testosterone release from the testes. FSH promotes early spermatogenesis. The male also secretes prostaglandins. These substances promote uterine contractions which help propel sperm towards an egg during sexual intercourse. Prostaglandins are produced in the seminal vesicles, and are not classified as hormones by all authorities.

5.Identify and describe the four lung volumes

1. Tidal Volume (TV) 2. Inspiratory Reserve Volume (IRV) 3. Expiratory Reserve Volume (ERV) 4. Residual Volume (RV) What is Tidal Volume (TV)? Volume of air inspired or expired with each normal breath. Normal Value: 500 ml (volume of quiet breath) What is Inspiratory Reserve Volume (IRV)? The volume of air inspired with maximal inspiratory effort, above tidal volume. usually: 3000-3500 ml What is Expiratory Reserve Volume (ERV)? The volume of air expelled with a forced expiratory effort, below tidal volume. usually: 1200-1500 ml What is Residual Volume (RV)? The volume of air in the lungs at the end of maximal forced expiration. usually: 1200 ml

6.Describe the function of Brunner's glands, Kupffer cells, goblet cells, intestinal crypts, and Peyer's patches

Brunner's glands The Brunner glands, which empty into the intestinal glands, secrete an alkaline fluid composed of mucin, which exerts a physiologic anti-acid function by coating the duodenal epithelium, therefore protecting it from the acid chyme of the stomach. Furthermore, in response to the presence of acid in the duodenum, these glands secrete pepsinogen and urogastrone, which inhibit gastric acid secretion.[citation needed] The main function of these glands is to produce a mucus-rich alkaline secretion (containing bicarbonate) in order to: protect the duodenum from the acidic content of chyme (which is introduced into the duodenum from the stomach); provide an alkaline condition for the intestinal enzymes to be active, thus enabling absorption to take place; lubricate the intestinal walls Kupffer cells-Kupffer cells, also known as Browicz-Kupffer cells and stellate macrophages, are specialized macrophages located in the liver lining the walls of the sinusoids that form part of the reticuloendothelial system (RES) (or mononuclear phagocyte system). Red blood cells are broken down by phagocytic action, where the hemoglobin molecule is split. The globin chains are re-utilized, while the iron-containing portion, heme, is further broken down into iron, which is re-utilized, and bilirubin, which is conjugated to glucuronic acid within hepatocytes and secreted into the bile. Helmy et al. identified a receptor present in Kupffer cells, the complement receptor of the immunoglobulin family (CRIg). Mice without CRIg could not clear complement system-coated pathogens. CRIg is conserved in mice and humans and is a critical component of the innate immune system. Goblet cells-A goblet cell is a glandular, modified simple columnar epithelial cell whose function is to secrete gel-forming mucins, the major components of mucus. The goblet cells mainly use the merocrine method of secretion, secreting vesicles into a duct, but may use apocrine methods, budding off their secretions, when under stress. The goblet cell is highly polarised with the nucleus and other organelles concentrated at the base of the cell. The remainder of the cell's cytoplasm is occupied by membrane-bound secretory granules containing mucin. The goblet shape is due to the mucus laden granules in the apical part expanding, causing that part of the cell to balloon. The apical plasma membrane projects microvilli to give an increased surface area for secretion. The main role of goblet cells is to secrete mucus in order to protect the mucous membranes where they are found. Goblet cells accomplish this by secreting mucins, large glycoproteins formed mostly by carbohydrates. The gel-like properties of mucins are given by its glycans (bound carbohydrates) attracting relatively large quantities of water.On the inner surface of the human intestine, it forms a 200 µm thick layer (less in other animals) that lubricates and protects the wall of the organ.Distinct forms of mucin are produced in different organs: while MUC2 is prevalent in the intestine, MUC5AC and MUC5B are the main forms found in the human airway.[8] Mucins are stored in granules inside the goblet cells before being released to the lumen of the organ.Secretion may be stimulated by irritants such as dust and smoke, especially in the airway. Other stimuli are microbes such as viruses and bacteria. Role in oral tolerance Oral tolerance is the process by which the immune system is prevented from responding to antigen derived from food products, as peptides from food may pass into the bloodstream via the gut, which would in theory lead to an immune response. A paper published in Nature in 2012 has shed some light on the process and implicated goblet cells as having a role in the process.It was known that CD103-expressing dendritic cells of the lamina propria had a role to play in the induction of oral tolerance (potentially by inducing the differentiation of regulatory T cells), and this paper suggests that the goblet cells act to preferentially deliver antigen to these CD103+ dendritic cells. intestinal crypts-In histology, an intestinal gland (also crypt of Lieberkühn and intestinal crypt) is a gland found in the epithelial lining of the small intestine and large intestine (colon). The glands and intestinal villi are covered by epithelium which contains multiple types of cells: enterocytes (absorbing water and electrolytes), goblet cells (secreting mucus), enteroendocrine cells (secreting hormones), tuft cells and, at the base of the gland, Paneth cells (secreting anti-microbial peptides) and stem cells. The enterocytes in the small intestinal mucosa contain digestive enzymes that digest specific foods while they are being absorbed through the epithelium. These enzymes include peptidase, sucrase, maltase, lactase and intestinal lipase. This is in contrast to the gastric glands of the stomach where chief cells secrete pepsinogen. Also, new epithelium is formed here, which is important because the cells at this site are continuously worn away by the passing food. The basal (further from the intestinal lumen) portion of the crypt contains multipotent stem cells. During each mitosis, one of the two daughter cells remains in the crypt as a stem cell, while the other differentiates and migrates up the side of the crypt and eventually into the villus. Goblet cells are among the cells produced in this fashion. Many genes have been shown to be important for the differentiation of intestinal stem cells. Loss of proliferation control in the crypts is thought to lead to colorectal cancer. Intestinal juice Intestinal juice refers to the clear to pale yellow watery secretions from the glands lining the small intestine walls. The Brunner's glands secrete large amounts of alkaline mucus in response to tactile or irritating stimuli on the duodenal mucosa; vagal stimulation, which causes increased Brunner's glands secretion concurrently with increase in stomach secretion; and gastrointestinal hormones, especially secretin. Its function is to complete the process begun by pancreatic juice; the enzyme trypsin exists in pancreatic juice in the inactive form trypsinogen, it is activated by the intestinal enterokinase in intestinal juice. Trypsin can then activate other protease enzymes and catalyze the reaction pro-colipase → colipase. Colipase is necessary, along with bile salts, to enable lipase function. Intestinal juice also contains hormones, digestive enzymes, mucus, substances to neutralize hydrochloric acid coming from the stomach and erepsin which further digests polypeptides into amino acids, completing protein digestion Peyer's Patch-Peyer's patches are small masses of lymphatic tissue found throughout the ileum region of the small intestine. Also known as aggregated lymphoid nodules, they form an important part of the immune system by monitoring intestinal bacteria populations and preventing the growth of pathogenic bacteria in the intestines. Peyer's patches are roughly egg-shaped lymphatic tissue nodules that are similar to lymph nodes in structure, except that they are not surrounded by a connective tissue capsule. They belong to a class of non-encapsulated lymphatic tissue known as lymphatic nodules, which include the tonsils and lymphatic tissue of the appendix. Special epithelial cells known as microfold cells line the side of the Peyer's patch facing the intestinal lumen, while the outer side contains many lymphoid cells and lymphatic vessels. The function of Peyer's patches is to analyze and respond to pathogenic microbes in the ileum. Antigens from microbes in the gut are absorbed via endocytosis by microfold cells lining the surface of each Peyer's patch. These antigens are passed on to the lymphoid tissue, where they are absorbed by macrophages and presented to T lymphocytes and B lymphocytes. When presented with dangerous pathogenic antigens, lymphocytes trigger the immune response by producing pathogen-specific antibodies; turning into pathogen-killing cytotoxic T lymphocytes; and migrating through lymphatic vessels to lymph nodes to alert the other cells of the immune system. The body then prepares a full body-wide immune response to the pathogen before it is able to spread beyond the intestines.

1.Describe the Layers of the wall of the Digestive Tract (mucosa,submucosa, muscularis, serosa)

4 layers (deep to superficial) Mucosa Submucosa Muscularis Externa Serosa (visceral peritoneum) Mucosa Lining of the lumen Composed of 3 layers (epithelial, areolar connective, smooth muscle) Contains lymph tissue Submucosa Contains the submucosal enteric neural plexus that controls GI secretions and localized blood flow Contains many glands which open into the lumen by way of ducts Contains lymph tissue Muscularis externa Skeletal muscle tissue Voluntary motor control Found in mouth, pharynx, upper esophagus and lower portion of the anal canal Smooth muscle tissue Found in the remainder of the GI tract Has nervous innervations Serosa Secretes serous peritoneal fluid Superficial layer of the viscera located in the abdominopelvic cavity

2.Identify and describe the parts of a typical nephron

A nephron is the basic structural and functional unit of the kidneys and its chief function is to regulate water and soluble substances in the blood by filtering the blood, reabsorbing what is needed and excreting the rest as urine . Its function is vital for homeostasis. It is regulated by the endocrine system by hormones such as antidiuretic hormone, aldosterone, and parathyroid hormone. Each nephron has its own supply of blood from two capillary regions from the renal artery. Each nephron is composed of an initial filtering component (the renal corpuscle) and a tubule specialized for reabsorption and secretion (the renal tubule). The renal corpuscle filters out large solutes from the blood, delivering water and small solutes to the renal tubule for modification. The glomerulus is a capillary tuft that receives its blood supply from an afferent arteriole of the renal circulation. Here, fluid and solutes are filtered out of the blood and into the space made by Bowman's capsule. A group of specialized cells known as juxtaglomerular cells are located around the afferent arteriole where it enters the renal corpuscle. The remainder of the blood not filtered into the glomerulus passes into the narrower efferent arteriole and moves into the vasa recta, collecting capillaries intertwined with the convoluted tubules through the interstitial space where the reabsorbed substances will also enter. The vasa recta combine with efferent venules from other nephrons into the renal vein and rejoins with the main bloodstream. Between the two efferent and afferent arterioles lies specialized cells called the macula densa. The juxtaglomerular cells and the macula densa collectively form the juxtaglomerular apparatus. It is in the juxtaglomerular apparatus cells that the enzyme renin is formed and stored. The Bowman's capsule (also called the glomerular capsule) surrounds the glomerulus. It is composed of visceral (simple squamous epithelial cells; inner) and parietal (simple squamous epithelial cells; outer) layers. The visceral layer lies just beneath the thickened glomerular basement membrane and is made of podocytes which send foot processes over the length of the glomerulus. Foot processes interdigitate with one another forming filtration slits that, in contrast to those in the glomeruluar endothelium, are spanned by diaphragms. The size of the filtration slits restricts the passage of large molecules (eg, albumin) and cells (eg, red blood cells and platelets). In addition, foot processes have a negatively-charged coat (glycocalyx) that limits the filtration of negatively-charged molecules, such as albumin. The parietal layer of Bowman's capsule is lined by a single layer of squamous epithelium. Between the visceral and parietal layers is Bowman's space, into which the filtrate enters after passing through the podocytes' filtration slits. It is here that smooth muscle cells and macrophages lie between the capillaries and provide support for them. Unlike the visceral layer, the parietal layer does not function in filtration. Rather, the filtration barrier is formed by three components: the diaphragms of the filtration slits, the thick glomerular basement membrane, and the glycocalyx secreted by podocytes. Together, the glomerulus and Bowman's capsule are called the renal corpuscle. The proximal tubule can be anatomically divided into two segments: the proximal convoluted tubule and the proximal straight tubule. The proximal convoluted tubule can be divided further into S1 and S2 segments based on the histological appearance of it's cells. Following this naming convention, the proximal straight tubule is commonly called the S3 segment. The proximal convoluted tubule has one layer of cuboidal cells in the lumen. This is the only place in the nephron that contains cuboidal cells. These cells are covered with millions of microvilli. The microvilli serve to increase surface area for reabsorption. The loop of Henle (sometimes known as the nephron loop) is a U-shaped tube that consists of a descending limb and ascending limb. It begins in the cortex, receiving filtrate from the proximal convoluted tubule, extends into the medulla, and then returns to the cortex to empty into the distal convoluted tubule. The descending limb is permeable to water but completely impermeable to salt, and thus only indirectly contributes to the concentration of the interstitium. In contrast, the ascending limb of Henle's loop is impermeable to water, a critical feature of the countercurrent exchange mechanism employed by the loop.

5.Identify and describe the chambers and valves of the heart. Describe blood flow through these chambers

A normal heart has two upper and two lower chambers. The upper chambers, the right and left atria, receive incoming blood. The lower chambers, the more muscular right and left ventricles, pump blood out of your heart. The heart valves, which keep blood flowing in the right direction, are gates at the chamber openings. right atrium (RA) right ventricle (RV) left atrium (LA) left ventricle (LV) Each chamber has a sort of one-way valve at its exit that prevents blood from flowing backwards. When each chamber contracts, the valve at its exit opens. When it is finished contracting, the valve closes so that blood does not flow backwards. The tricuspid valve is at the exit of the right atrium. The pulmonary valve is at the exit of the right ventricle. The mitral valve is at the exit of the left atrium. The aortic valve is at the exit of the left ventricle. When the heart muscle contracts or beats (called systole), it pumps blood out of the heart. The heart contracts in two stages. In the first stage, the right and left atria contract at the same time, pumping blood to the right and left ventricles. Then the ventricles contract together to propel blood out of the heart. Then the heart muscle relaxes (called diastole) before the next heartbeat. This allows blood to fill up the heart again. The right and left sides of the heart have separate functions. The right side of the heart collects oxygen-poor blood from the body and pumps it to the lungs where it picks up oxygen and releases carbon dioxide. The left side of the heart then collects oxygen-rich blood from the lungs and pumps it to the body so that the cells throughout your body have the oxygen they need to function properly.

3.Describe the hormones produced or released by the pituitary gland. Include the functions of those hormones. (3 questions)

Anterior pituitary Adrenocorticotrophic hormone (ACTH) Thyroid-stimulating hormone (TSH) Luteinising hormone (LH) Follicle-stimulating hormone (FSH) Prolactin (PRL) Growth hormone (GH) Melanocyte-stimulating hormone (MSH) Posterior pituitary Anti-diuretic hormone (ADH) Oxytocin

6.Discuss the implantation of the blastocyst into the uterine wall

As cell division proceeds, the embryo is on the move. The uterine tube steers the embryo toward the uterus by cilia motion of epithelial cells lining the uterine tube wall and continued mild muscle contractions.The cells of the corona radiata disappear within about 2 days while the zona persists in protecting the embryo and preventing premature implantation in the uterine tube. By about 3 days after fertilization, while still in the uterine tube, the embryo contains 12 to 16 cells configured as a solid ball of cells and is called a morula (mor'u-la) Approximately 3 1/2 to 4 days after fertilization, the uterine tube relaxes under the influence of progesterone and the embryo completes its journey through the uterine tube and enters the uterus.68 By this time the embryo begins to develop a fluid-filled cavity with a collection of cells at one end and is called a blastocyst. The surface of the blastocyst adjacent to the inner cell mass is referred to as the polar end or embryonic pole of the blastocyst. The zona pellucida, having delivered the embryo through the maze of the uterine tube, degenerates shortly after the embryo arrives in the uterus.Embryos studied outside the uterus in a process sometimes called "hatching. The now-free blastocyst is now ready to find a permanent home inside the wall of the uterus. Implantation is the process whereby the early embryo embeds into the inner wall of the mother's uterus. Implantation begins about 6 days after fertilization and is complete by about 12 days. The first step of this process is the attachment phase, which begins about 6 days after fertilization. The outer cells (trophoblast cells) of the blastocyst have specialized adhesion molecules81 which bind to the epithelial cells of the endometrium. The cells in the uterine wall are full of nutrients and water. The blastocyst attaches between the uterine glands, along its surface overlying the inner cell mass (the embryonic pole). Once attached. the trophoblast cells release enzymes that digest, liquify, and separate maternal cells forming an entry way inside the uterine wall. The trophoblast cells capture the local nutrients and actively share them with the inner cell mass. Implantation represents a significant obstacle to the developing embryo. It is estimated that up to one-half of all embryos fail to successfully implant and die - often without the mother realizing she is pregnant. Many of these embryos are thought to have severe genetic abnormalities incompatible with survival. By the end of the first week, the embryo has traveled extensively, multiplied from 1 cell to several hundred, dramatically changed its shape and complexity, and begun the process of finding permanent housing.

2.Describe the components of the blood (including are parts of the plasma and formed elements) and their respective functions

Blood is a specialized body fluid. It has four main components: plasma, red blood cells, white blood cells, and platelets. Blood has many different functions, including: -transporting oxygen and nutrients to the lungs and tissues -forming blood clots to prevent excess blood loss -carrying cells and antibodies that fight infection -bringing waste products to the kidneys and liver, which filter and clean the blood -regulating body temperature The blood that runs through the veins, arteries, and capillaries is known as whole blood, a mixture of about 55 percent plasma and 45 percent blood cells. About 7 to 8 percent of your total body weight is blood. An average-sized man has about 12 pints of blood in his body, and an average-sized woman has about 9 pints. Plasma The liquid component of blood is called plasma, a mixture of water, sugar, fat, protein, and salts. The main job of the plasma is to transport blood cells throughout your body along with nutrients, waste products, antibodies, clotting proteins, chemical messengers such as hormones, and proteins that help maintain the body's fluid balance. Red Blood Cells (also called erythrocytes or RBCs) Known for their bright red color, red cells are the most abundant cell in the blood, accounting for about 40-45 percent of its volume. The shape of a red blood cell is a biconcave disk with a flattened center - in other words, both faces of the disc have shallow bowl-like indentations (a red blood cell looks like a donut). Production of red blood cells is controlled by erythropoietin, a hormone produced primarily by the kidneys. Red blood cells start as immature cells in the bone marrow and after approximately seven days of maturation are released into the bloodstream. Unlike many other cells, red blood cells have no nucleus and can easily change shape, helping them fit through the various blood vessels in your body. However, while the lack of a nucleus makes a red blood cell more flexible, it also limits the life of the cell as it travels through the smallest blood vessels, damaging the cell's membranes and depleting its energy supplies. The red blood cell survives on average only 120 days. Red cells contain a special protein called hemoglobin, which helps carry oxygen from the lungs to the rest of the body and then returns carbon dioxide from the body to the lungs so it can be exhaled. Blood appears red because of the large number of red blood cells, which get their color from the hemoglobin. The percentage of whole blood volume that is made up of red blood cells is called the hematocrit and is a common measure of red blood cell levels. White Blood Cells (also called leukocytes) White blood cells protect the body from infection. They are much fewer in number than red blood cells, accounting for about 1 percent of your blood. The most common type of white blood cell is the neutrophil, which is the "immediate response" cell and accounts for 55 to 70 percent of the total white blood cell count. Each neutrophil lives less than a day, so your bone marrow must constantly make new neutrophils to maintain protection against infection. Transfusion of neutrophils is generally not effective since they do not remain in the body for very long. The other major type of white blood cell is a lymphocyte. There are two main populations of these cells. T lymphocytes help regulate the function of other immune cells and directly attack various infected cells and tumors. B lymphocytes make antibodies, which are proteins that specifically target bacteria, viruses, and other foreign materials. Platelets (also called thrombocytes) Unlike red and white blood cells, platelets are not actually cells but rather small fragments of cells. Platelets help the blood clotting process (or coagulation) by gathering at the site of an injury, sticking to the lining of the injured blood vessel, and forming a platform on which blood coagulation can occur. This results in the formation of a fibrin clot, which covers the wound and prevents blood from leaking out. Fibrin also forms the initial scaffolding upon which new tissue forms, thus promoting healing. A higher than normal number of platelets can cause unnecessary clotting, which can lead to strokes and heart attacks; however, thanks to advances made in antiplatelet therapies, there are treatments available to help prevent these potentially fatal events. Conversely, lower than normal counts can lead to extensive bleeding.

7. Describe the absorption process of carbohydrates, proteins, and lipids

Carbohydrates Carbohydrates are your body's preferred energy source and are found in the forms of starch, sugar and fiber. Digestion begins in your mouth where the process of chewing mechanically breaks food into small pieces. Enzymes in the saliva initiate chemical digestion. When you swallow, partially digested carbs travel down your esophagus to the stomach with little additional digestion. From there, carbohydrates move into the small intestine where enzymes released by the pancreas break them into simple forms to be absorbed into the bloodstream. Fiber is indigestible and passes through your gastrointestinal tract without being broken down. Lipids Most lipids that you consume in your diet are fats. Some digestion occurs in your mouth and the stomach, but most takes place in the small intestine. Bile is produced by your liver, stored and released in your gall bladder and emulsifies fat globules into smaller droplets. This greatly increases the surface area that allows lipase, a fat-digesting pancreatic enzyme, to aid in digestion. After digestion, these broken-down fat particles called fatty acids combine with cholesterol and bile to move into your cells' mucosa where they are reconverted into large molecules, most passing into vessels -- called lymphatics -- near the intestine. These vessels transport fat to the veins of your chest, and the blood carries fat to be stored in adipose tissue throughout your body. Proteins Protein is found in meat, eggs, dairy products, fish, nuts and beans. Before your body can use protein to build and repair tissues, the large molecules of protein must be digested by enzymes into small molecules called amino acids. Digestion of protein begins in your stomach with the aid of gastric juices. Through the action of a group of potent enzymes from the intestinal lining and the pancreas, digestion continues in the small intestine. From there, amino acids are absorbed into the bloodstream and transported throughout your body.

11.Identify the areas of the digestive system where carbohydrates, proteins and lipids are digested

Carbohydrates The digestion of carbohydrates begins in the mouth. The salivary enzyme amylase begins the breakdown of food starches into maltose, a disaccharide. As the food travels through the esophagus to the stomach, no significant digestion of carbohydrates takes place. The acidic environment in the stomach stops the action of the amylase enzyme. The next step of carbohydrate digestion takes place in the duodenum. The chyme from the stomach enters the duodenum and mixes with the digestive secretions from the pancreas, liver, and gallbladder. Pancreatic juices also contain amylase, which continues the breakdown of starch and glycogen into maltose and other disaccharides. These disaccharides are then broken down into monosaccharides by enzymes called maltases, sucrases, and lactases. The monosaccharides produced are absorbed so that they can be used in metabolic pathways to harness energy. They are absorbed across the intestinal epithelium into the bloodstream to be transported to the different cells in the body . Protein A large part of protein digestion takes place in the stomach. The enzyme pepsin plays an important role in the digestion of proteins by breaking them down into peptides (short chains of four to nine amino acids). In the duodenum, other enzymes, trypsin, elastase, and chymotrypsin, act on the peptides, reducing them to smaller peptides. These enzymes are produced by the pancreas and released into the duodenum where they also act on the chyme. Further breakdown of peptides to single amino acids is aided by enzymes called peptidases (those that break down peptides). The amino acids are absorbed into the bloodstream through the small intestine . Lipids Lipid (fat) digestion begins in the stomach with the aid of lingual lipase and gastric lipase. However, the bulk of lipid digestion occurs in the small intestine due to pancreatic lipase. When chyme enters the duodenum, the hormonal responses trigger the release of bile, which is produced in the liver and stored in the gallbladder. Bile aids in the digestion of lipids, primarily triglycerides, by emulsification. Emulsification is a process in which large lipid globules are broken down into several small lipid globules. These small globules are widely distributed in the chyme rather than forming large aggregates. Lipids are hydrophobic substances. Bile contains bile salts, which have hydrophobic and hydrophilic sides. The bile salts' hydrophilic side can interface with water, while the hydrophobic side interfaces with lipids, thereby emulsifying large lipid globules into small lipid globules. Emulsification is important for the digestion of lipids because lipases can only efficiently act on the lipids when they are broken into small aggregates. Lipases break down the lipids into fatty acids and glycerides. These molecules can pass through the plasma membrane of the cell, entering the epithelial cells of the intestinal lining. The bile salts surround long-chain fatty acids and monoglycerides, forming tiny spheres called micelles. The micelles move into the brush border of the small intestine absorptive cells where the long-chain fatty acids and monoglycerides diffuse out of the micelles into the absorptive cells, leaving the micelles behind in the chyme. The long-chain fatty acids and monoglycerides recombine in the absorptive cells to form triglycerides, which aggregate into globules, becoming coated with proteins. These large spheres are called chylomicrons. Chylomicrons contain triglycerides, cholesterol, and other lipids; they have proteins on their surface. The surface is also composed of the hydrophilic phosphate "heads" of phospholipids. Together, they enable the chylomicron to move in an aqueous environment without exposing the lipids to water. Chylomicrons leave the absorptive cells via exocytosis, entering the lymphatic vessels. From there, they enter the blood in the subclavian vein .

11.Define cardiac output. Describe the factors that affect cardiac out

Cardiac output is the amount of blood the heart pumps in 1 minute, and it is dependent on the heart rate, contractility, preload, and afterload.

10.Describe the process of clotting. Identify the enzymes and co-enzymes required.

Clotting factors are proteins in the blood that control bleeding. When a blood vessel is injured, the walls of the blood vessel contract to limit the flow of blood to the damaged area. Then, small blood cells called platelets stick to the site of injury and spread along the surface of the blood vessel to stop the bleeding. At the same time, chemical signals are released from small sacs inside the platelets that attract other cells to the area and make them clump together to form what is called a platelet plug. On the surface of these activated platelets, many different clotting factors work together in a series of complex chemical reactions (known as the coagulation cascade) to form a fibrin clot. The clot acts like a mesh to stop the bleeding. Coagulation factors circulate in the blood in an inactive form. When a blood vessel is injured, the coagulation cascade is initiated and each coagulation factor is activated in a specific order to lead to the formation of the blood clot. The production of factor X results in the cleavage of prothrombin (factor II) to thrombin (factor IIa). Thrombin, in turn, catalyzes the conversion of fibrinogen (factor I)—a soluble plasma protein—into long, sticky threads of insoluble fibrin (factor Ia). The fibrin threads form a mesh that traps platelets, blood cells, and plasma.

2.Describe Structures and functions of the Digestive Tract

Digestive organs fall into two main groups: the alimentary canal and the accessory organs. • The alimentary canal, or GI tract, is the continuous muscular digestive tube that winds through the body digesting and absorbing foodstuff; its organs include: the mouth, pharynx, esophagus, stomach, small intestine, and large intestine. • Accessory digestive organs or structures aid digestion physically and produce secretions that break down foodstuff in the GI tract; the organs involved are the teeth, tongue, gallbladder, salivary glands, liver and pancreas. List and define the major processes occurring digestive system activity. • Ingestion: the simple act of putting food into the mouth • Propulsion or Motility: moves food through the alimentary canal and includes both swallowing and peristalsis. • Mechanical Breakdown or Digestion: the physical process of preparing the food for chemical digestion and involves chewing, mixing, churning and segmentation. • Chemical Digestion: a series of catabolic steps in which complex food molecules are broken down to their chemical building blocks by the secretion of enzymes and various secretions (acid, bile, etc...) • Absorption: the passage of digested end products from the lumen of the GI tract through the mucosal cells into the blood or lymph. • Defecation or Elimination: eliminates indigestibles substances from the body via the anus as feces. ❊ Segmentation: rhythmic local constrictions of the small intestine. Segmentation mixes food with digestive juices and makes absorption more efficient by repeatedly moving different parts of the food mass over the intestinal wall.

4.Describe urine flow from the collecting duct to the ureter

Each distal convoluted tubule delivers its filtrate to a system of collecting ducts, the first segment of which is the connecting tubule. The collecting duct system begins in the renal cortex and extends deep into the medulla. As the urine travels down the collecting duct system, it passes by the medullary interstitium which has a high sodium concentration as a result of the loop of Henle's countercurrent multiplier system. Though the collecting duct is normally impermeable to water, it becomes permeable in the presence of antidiuretic hormone (ADH). As much as three-fourths of the water from urine can be reabsorbed as it leaves the collecting duct by osmosis. Thus the levels of ADH determine whether urine will be concentrated or dilute. Dehydration results in an increase in ADH, while water sufficiency results in low ADH allowing for diluted urine. Lower portions of the collecting duct are also permeable to urea, allowing some of it to enter the medulla of the kidney, thus maintaining its high ion concentration (which is very important for the nephron). Urine leaves the medullary collecting ducts through the renal papilla, emptying into the renal calyces, the renal pelvis, and finally into the bladder via the ureter. Because it has a different embryonic origin than the rest of the nephron (the collecting duct is from endoderm whereas the nephron is from mesoderm), the collecting duct is usually not considered a part of the nephron proper.

1.Identify the functions of the cardiovascular system

Knowing the functions of the cardiovascular system and the parts of the body that are part of it is critical in understanding the physiology of the human body. With its complex pathways of veins, arteries, and capillaries, the cardiovascular system keeps life pumping through you. The heart, blood vessels, and blood help to transport vital nutrients throughout the body as well as remove metabolic waste. They also help to protect the body and regulate body temperature. The cardiovascular system consists of the heart, blood vessels, and blood. This system has three main functions: Transport of nutrients, oxygen, and hormones to cells throughout the body and removal of metabolic wastes (carbon dioxide, nitrogenous wastes). Protection of the body by white blood cells, antibodies, and complement proteins that circulate in the blood and defend the body against foreign microbes and toxins. Clotting mechanisms are also present that protect the body from blood loss after injuries. Regulation of body temperature, fluid pH, and water content of cells.

4.Identify and describe the phases of the female reproductive cycle. Include the hormones and structures involved with this process

Menstruation is the shedding of the lining of the uterus (endometrium) accompanied by bleeding. It occurs in approximately monthly cycles throughout a woman's reproductive life, except during pregnancy. Menstruation starts during puberty (at menarche) and stops permanently at menopause (see Menopause). By definition, the menstrual cycle begins with the first day of bleeding, which is counted as day 1. The cycle ends just before the next menstrual period. Menstrual cycles normally range from about 25 to 36 days. Only 10 to 15% of women have cycles that are exactly 28 days. Also, in at least 20% of women, cycles are irregular. That is, they are longer or shorter than the normal range. Usually, the cycles vary the most and the intervals between periods are longest in the years immediately after menarche and before menopause. Menstrual bleeding lasts 3 to 7 days, averaging 5 days. Blood loss during a cycle usually ranges from 1/2 to 2 1/2 ounces. A sanitary pad or tampon, depending on the type, can hold up to an ounce of blood. Menstrual blood, unlike blood resulting from an injury, usually does not clot unless the bleeding is very heavy. The menstrual cycle is regulated by hormones. Luteinizing hormone and follicle-stimulating hormone, which are produced by the pituitary gland, promote ovulation and stimulate the ovaries to produce estrogen and progesterone . Estrogen and progesterone stimulate the uterus and breasts to prepare for possible fertilization. The cycle has three phases: follicular (before release of the egg), ovulatory (egg release), and luteal (after egg release). Follicular phase This phase begins on the first day of menstrual bleeding (day 1). But the main event in this phase is the development of follicles in the ovaries. At the beginning of the follicular phase, the lining of the uterus (endometrium) is thick with fluids and nutrients designed to nourish an embryo. If no egg has been fertilized, estrogen and progesterone levels are low. As a result, the top layers of the endometrium are shed, and menstrual bleeding occurs. About this time, the pituitary gland slightly increases its production of follicle-stimulating hormone. This hormone then stimulates the growth of 3 to 30 follicles. Each follicle contains an egg. Later in the phase, as the level of this hormone decreases, only one of these follicles (called the dominant follicle) continues to grow. It soon begins to produce estrogen , and the other stimulated follicles begin to break down. The increasing estrogen also begins to prepare the uterus and stimulates the luteinizing hormone surge. On average, the follicular phase lasts about 13 or 14 days. Of the three phases, this phase varies the most in length. It tends to become shorter near menopause. This phase ends when the level of luteinizing hormone increases dramatically (surges). The surge results in release of the egg (ovulation). Ovulatory phase This phase begins when the level of luteinizing hormone surges. Luteinizing hormone stimulates the dominant follicle to bulge from the surface of the ovary and finally rupture, releasing the egg. The level of follicle-stimulating hormone increases to a lesser degree. The function of the increase in follicle-stimulating hormone is not understood. The ovulatory phase usually lasts 16 to 32 hours. It ends when the egg is released, about 10 to 12 hours after the surge in the level of luteinizing hormone. The egg can be fertilized for only up to about 12 hours after its release. The surge in luteinizing hormone can be detected by measuring the level of this hormone in urine. This measurement can be used to determine when women are fertile. Fertilization is more likely when sperm are present in the reproductive tract before the egg is released. Most pregnancies occur when intercourse occurs within 3 days before ovulation. Around the time of ovulation, some women feel a dull pain on one side of the lower abdomen. This pain is known as mittelschmerz (literally, middle pain). The pain may last for a few minutes to a few hours. The pain is usually felt on the same side as the ovary that released the egg, but the precise cause of the pain is unknown. The pain may precede or follow the rupture of the follicle and may not occur in all cycles. Egg release does not alternate between the two ovaries and appears to be random. If one ovary is removed, the remaining ovary releases an egg every month. Luteal phase This phase begins after ovulation. It lasts about 14 days (unless fertilization occurs) and ends just before a menstrual period. In this phase, the ruptured follicle closes after releasing the egg and forms a structure called a corpus luteum, which produces increasing quantities of progesterone . The progesterone produced by the corpus luteum prepares the uterus in case an embryo is implanted. The progesterone causes the endometrium to thicken, filling with fluids and nutrients to nourish a potential embryo. Progesterone causes the mucus in the cervix to thicken, so that sperm or bacteria are less likely to enter the uterus. Progesterone also causes body temperature to increase slightly during the luteal phase and remain elevated until a menstrual period begins. This increase in temperature can be used to estimate whether ovulation has occurred (see Problems With Ovulation). During most of the luteal phase, the estrogen level is high. Estrogen also stimulates the endometrium to thicken. The increase in estrogen and progesterone levels causes milk ducts in the breasts to widen (dilate). As a result, the breasts may swell and become tender. If the egg is not fertilized or if the fertilized egg does not implant, the corpus luteum degenerates after 14 days, levels of estrogen and progesterone decrease, and a new menstrual cycle begins. If the embryo is implanted, the cells around the developing embryo begin to produce a hormone called human chorionic gonadotropin. This hormone maintains the corpus luteum, which continues to produce progesterone , until the growing fetus can produce its own hormones. Pregnancy tests are based on detecting an increase in the human chorionic gonadotropin level.

6.Identify the factors that affect respiratory rate

Non-neural factors influencing respiratory rate and depth (physical) increased body temperature - exercise - talking - coughing Non-neural factors influencing respiratory rate and depth (chemical factors: carbon dioxide levels) - the body's need to rid itself of carbon dioxide is the most important stimulus - increased levels of carbon dioxide in the blood increases the rate and depth of breathing - changes in carbon dioxide act directly on the medulla oblongata through pH change in the cerebrospinal fluid Non-neural factors influencing respiratory rate and depth (chemical factors: oxygen levels) - Changes in oxygen concentration in the blood are detected by chemoreceptors in the aorta and common carotid artery - information is sent to the medulla

5.Describe the functions of Antidiuretic Hormone

One of the most important roles of AVP is to regulate the body's retention of water; it is released when the body is dehydrated and causes the kidneys to conserve water, thus concentrating the urine and reducing urine volume. At high concentrations, it also raises blood pressure by inducing moderate vasoconstriction. In addition, it has a variety of neurological effects on the brain, having been found, for example, to influence pair-bonding in voles. The high-density distributions of vasopressin receptor AVPr1a in prairie vole ventral forebrain regions have been shown to facilitate and coordinate reward circuits during partner preference formation, critical for pair bond formation. Vasopressin has two main effects by which it contributes to increased urine osmolarity (increased concentration) and decreased water excretion: Increasing the water permeability of distal convoluted tubule and collecting duct cells in the kidney, thus allowing water reabsorption and excretion of more concentrated urine, i.e., antidiuresis. This occurs through insertion of water channels (Aquaporin-2) into the apical membrane of distal convoluted tubule and collecting duct epithelial cells. Aquaporins allow water to move down their osmotic gradient and out of the nephron, increasing the amount of water re-absorbed from the filtrate (forming urine) back into the bloodstream. V2 receptors, which are G protein-coupled receptors on the basolateral plasma membrane of the epithelial cells, couple to the heterotrimeric G-protein Gs, which activates adenylyl cyclases III and VI to convert ATP into cAMP, plus 2 inorganic phosphates. The rise in cAMP then triggers the insertion of aquaporin-2 water channels by exocytosis of intracellular vesicles containing AQP channels, recycling endosomes. Vasopressin also increases the concentration of calcium in the collecting duct cells, by episodic release from intracellular stores. Vasopressin, acting through cAMP, also increases transcription of the aquaporin-2 gene, thus increasing the total number of aquaporin-2 molecules in collecting duct cells. Cyclic-AMP activates protein kinase A (PKA) by binding to its regulatory subunits and allowing them to detach from the catalytic subunits. Detachment exposes the catalytic site in the enzyme, allowing it to add phosphate groups to proteins (including the aquaporin-2 protein), which alters their functions. Increasing permeability of the inner medullary portion of the collecting duct to urea by regulating the cell surface expression of urea transporters,[7] which facilitates its reabsorption into the medullary interstitium as it travels down the concentration gradient created by removing water from the connecting tubule, cortical collecting duct, and outer medullary collecting duct. Acute increase of sodium absorption across the ascending loop of henle. This adds to the countercurrent multiplication which aids in proper water reabsorption later in the distal tubule and collecting duct. Serum osmolarity/osmolality is also effected by vasopressin due to its role in keeping proper electrolytic balance in the blood stream. Improper balance can lead to dehydration, alkalosis, acidosis or other life-threatening changes. The hormone ADH is partly responsible for this process by controlling the amount of water the body retains from the kidney when filtering the blood stream.

7.Describe the factors that affect hemoglobin saturation

PO2,PC02, temperature, blood pH, and concentration of BPG -ensure adequate delivery of oxygen to tissue cells temperature, H+, PCO2, and BPG -alter hemoglobin's affinity for oxygen -if these increase, it will: 1.decrease hemoglobin's affinity for oxygen 2.enhance oxygen unloading from the blood

1.Identify and discuss the parts of the male reproductive system

Penis: This is the male organ used in sexual intercourse. It has three parts: the root, which attaches to the wall of the abdomen; the body, or shaft; and the glans, which is the cone-shaped part at the end of the penis. The glans, also called the head of the penis, is covered with a loose layer of skin called foreskin. This skin is sometimes removed in a procedure called circumcision. The opening of the urethra, the tube that transports semen and urine, is at the tip of the penis. The glans of the penis also contains a number of sensitive nerve endings. The body of the penis is cylindrical in shape and consists of three circular shaped chambers. These chambers are made up of special, sponge-like tissue. This tissue contains thousands of large spaces that fill with blood when the man is sexually aroused. As the penis fills with blood, it becomes rigid and erect, which allows for penetration during sexual intercourse. The skin of the penis is loose and elastic to accommodate changes in penis size during an erection. Semen, which contains sperm (reproductive cells), is expelled (ejaculated) through the end of the penis when the man reaches sexual climax (orgasm). When the penis is erect, the flow of urine is blocked from the urethra, allowing only semen to be ejaculated at orgasm. Scrotum: This is the loose pouch-like sac of skin that hangs behind and below the penis. It contains the testicles (also called testes), as well as many nerves and blood vessels. The scrotum acts as a "climate control system" for the testes. For normal sperm development, the testes must be at a temperature slightly cooler than body temperature. Special muscles in the wall of the scrotum allow it to contract and relax, moving the testicles closer to the body for warmth or farther away from the body to cool the temperature. Testicles (testes): These are oval organs about the size of large olives that lie in the scrotum, secured at either end by a structure called the spermatic cord. Most men have two testes. The testes are responsible for making testosterone, the primary male sex hormone, and for generating sperm. Within the testes are coiled masses of tubes called seminiferous tubules. These tubes are responsible for producing sperm cells. Epididymis: The epididymis is a long, coiled tube that rests on the backside of each testicle. It transports and stores sperm cells that are produced in the testes. It also is the job of the epididymis to bring the sperm to maturity, since the sperm that emerge from the testes are immature and incapable of fertilization. During sexual arousal, contractions force the sperm into the vas deferens. Vas deferens: The vas deferens is a long, muscular tube that travels from the epididymis into the pelvic cavity, to just behind the bladder. The vas deferens transports mature sperm to the urethra, the tube that carries urine or sperm to outside of the body, in preparation for ejaculation. Ejaculatory ducts: These are formed by the fusion of the vas deferens and the seminal vesicles (see below). The ejaculatory ducts empty into the urethra. Urethra: The urethra is the tube that carries urine from the bladder to outside of the body. In males, it has the additional function of ejaculating semen when the man reaches orgasm. When the penis is erect during sex, the flow of urine is blocked from the urethra, allowing only semen to be ejaculated at orgasm. Seminal vesicles: The seminal vesicles are sac-like pouches that attach to the vas deferens near the base of the bladder. The seminal vesicles produce a sugar-rich fluid (fructose) that provides sperm with a source of energy to help them move. The fluid of the seminal vesicles makes up most of the volume of a man's ejaculatory fluid, or ejaculate. Prostate gland: The prostate gland is a walnut-sized structure that is located below the urinary bladder in front of the rectum. The prostate gland contributes additional fluid to the ejaculate. Prostate fluids also help to nourish the sperm. The urethra, which carries the ejaculate to be expelled during orgasm, runs through the center of the prostate gland. Bulbourethral glands: Also called Cowper's glands, these are pea-sized structures located on the sides of the urethra just below the prostate gland. These glands produce a clear, slippery fluid that empties directly into the urethra. This fluid serves to lubricate the urethra and to neutralize any acidity that may be present due to residual drops of urine in the urethra.

8.Define peristalsis, segmentation, deglutition and mastication

Peristalsis is a series of wave-like muscle contractions that moves food to different processing stations in the digestive tract. The process of peristalsis begins in the esophagus when a bolus of food is swallowed. The strong wave-like motions of the smooth muscle in the esophagus carry the food to the stomach, where it is churned into a liquid mixture called chyme. Next, peristalsis continues in the small intestine where it mixes and shifts the chyme back and forth, allowing nutrients to be absorbed into the bloodstream through the small intestine walls. Peristalsis concludes in the large intestine where water from the undigested food material is absorbed into the bloodstream. Finally, the remaining waste products are excreted from the body through the rectum and anus. Segmentation Peristalsis moves food along the small intestine, but we also see two other movements within the organ. While these two movements do not push the food along the tract like peristalsis, they do mix the chyme with the digestive juices and bring particles of food into contact with the wall where they can be absorbed. Segmentation is one of these movements. It is a localized contraction of circular smooth muscles that constricts the intestine into segments. This is a rhythmic movement that involves the contraction and relaxation of adjacent segments of muscles as if the small intestine is being momentarily pinched closed along its path. Segmentation acts to slosh the chyme back and forth almost like it is being tossed around in a washing machine. This fully mixes the chyme and allows it to come in contact with the wall. Swallowing, sometimes called deglutition in scientific contexts, is the process in the human or animal body that makes something pass from the mouth, to the pharynx, and into the esophagus, while shutting the epiglottis. Swallowing is an important part of eating and drinking. If the process fails and the material (such as food, drink, or medicine) goes through the trachea, then choking or pulmonary aspiration can occur. In the human body the automatic temporary closing of the epiglottis is controlled by the swallowing reflex. The portion of food, drink, or other material that will move through the neck in one swallow is called a bolus. Mastication or chewing is the process by which food is crushed and ground by teeth. It is the first step of digestion, and it increases the surface area of foods to allow more efficient break down by enzymes. During the mastication process, the food is positioned by the cheek and tongue between the teeth for grinding. The muscles of mastication move the jaws to bring the teeth into intermittent contact, repeatedly occluding and opening. As chewing continues, the food is made softer and warmer, and the enzymes in saliva begin to break down carbohydrates in the food. After chewing, the food (now called a bolus) is swallowed. It enters the esophagus and via peristalsis continues on to the stomach, where the next step of digestion occurs. Premastication is sometimes performed by human parents for infants who are unable to do so for themselves. The food is masticated in the mouth of the parent into a bolus and then transferred to the infant for consumption.(Some other animals also premasticate.) Cattle and some other animals, called ruminants, chew food more than once to extract more nutrients. After the first round of chewing, this food is called cud.

3.Describe the process of erythropoiesis (red blood cell production)

Red blood cell (RBC) production (erythropoiesis) takes place in the bone marrow under the control of the hormone erythropoietin (EPO). Juxtaglomerular cells in the kidney produce EPO in response to decreased O 2 delivery (as in anemia and hypoxia) and increased levels of androgens. In addition to EPO, RBC production requires adequate supplies of substrates, mainly iron, vitamin B 12 , and folate. RBCs survive about 120 days. They then lose their cell membranes and are largely cleared from the circulation by the phagocytic cells of the spleen, liver, and bone marrow. Hb is broken down in these cells and in hepatocytes primarily by the heme oxygenase system with conservation (and subsequent reutilization) of iron, degradation of heme to bilirubin through a series of enzymatic steps, and reutilization of protein. Maintenance of a steady number of RBCs requires daily renewal of 1/120 of the cells; immature RBCs (reticulocytes) are continually released and constitute 0.5 to 1.5% of the peripheral RBC population. Low levels of androgens are associated with decreased EPO levels in women and girls and in elderly patients can predispose to anemia, as does the decline in the capacity of bone marrow to produce RBCs. With aging, Hb and Hct decrease slightly, but not below normal values. In women, other factors that frequently contribute to lower levels of RBCs include cumulative menstrual blood loss and increased demand for iron due to multiple pregnancies.

2.Describe the process of sperm production (spermatogenesis)

Spermatogenesis is the process in which spermatozoa are produced from male primordial sperm cells by way of mitosis and meiosis. The initial cells in this pathway are called spermatogonia, which yield primary spermatocytes by mitosis. The primary spermatocyte divides meiotically (Meiosis I) into two secondary spermatocytes; each secondary spermatocyte divides into two spermatids by Meiosis II. These develop into mature spermatozoa, also known as sperm cells. Thus, the primary spermatocyte gives rise to two cells, the secondary spermatocytes, and the two secondary spermatocytes by their subdivision produce four spermatozoa. Spermatozoa are the mature male gametes in many sexually reproducing organisms. Thus, spermatogenesis is the male version of gametogenesis, of which the female equivalent is oogenesis. In mammals it occurs in the seminiferous tubules of the male testes in a stepwise fashion. Spermatogenesis is highly dependent upon optimal conditions for the process to occur correctly, and is essential for sexual reproduction. DNA methylation and histone modification have been implicated in the regulation of this process. It starts at puberty and usually continues uninterrupted until death, although a slight decrease can be discerned in the quantity of produced sperm with increase in age .

8.Define systole and diastole

Systole is the contraction phase of the cardiac cycle (contrast with diastole) that results in the ejection of blood into an adjacent chamber or vessel. Electrical systole can be recorded on an electrocardiogram (ECG) and precedes mechanical systole (the actual contraction). Diastole is the part of the cardiac cycle when the heart refills with blood following systole (contraction). Ventricular diastole is the period during which the ventricles are filling and relaxing, while atrial diastole is the period during which the atria are relaxing.

2.Describe the hormones produced by the thyroid. Include the functions of those hormones.

The 2 main thyroid hormones are T3 (triiodothyronine) and T4 (thyroxine). The amount of thyroid hormones secreted is controlled by another hormone, called thyroid stimulating hormone (TSH), which is released from the pituitary gland in your head. Triiodothyronine-Triiodothyronine is the active form of the thyroid hormone, thyroxine. Approximately 20% of triiodothyronine is secreted into the bloodstream directly by the thyroid gland. The remaining 80% is produced from conversion of thyroxine by organs such as the liver and kidneys. Thyroid hormones play vital roles in regulating the body's metabolic rate, heart and digestive functions, muscle control, brain development and the maintenance of bones. Thyroxine-Thyroxine is the main hormone secreted into the bloodstream by the thyroid gland. It is the inactive form and most of it is converted to an active form called triiodothyronine by organs such as the liver and kidneys. Thyroid hormones play vital roles in regulating the body's metabolic rate, heart and digestive functions, muscle control, brain development and maintenance of bones.

4.Describe the hormones produced by the adrenal gland. Include the functions of those hormones.

The adrenal cortex produces three hormones: Mineralocorticoids: the most important of which is aldosterone. This hormone helps to maintain the body's salt and water levels which, in turn, regulates blood pressure. Without aldosterone, the kidney loses excessive amounts of salt (sodium) and, consequently, water, leading to severe dehydration. Glucocorticoids: predominantly cortisol. This hormone is involved in the stress response and also helps to regulate body metabolism. Cortisol stimulates glucose production by mobilising amino acids and free fatty acids. Cortisol also has significant anti-inflammatory effects. Adrenal androgens: male sex hormones mainly dehydroepiandrosterone (DHEA) and testosterone. All have weak effects, but play a role in early development of the male sex organs in childhood, and in women during puberty. These are involved in creating and maintaining the differences between men and women. Adrenocorticotropic hormone (ACTH) secreted by the anterior pituitary primarily affects release of glucocorticoids and adrenal androgens by the adrenal and to a lesser extent, also stimulates aldosterone release. The adrenal medulla produces catecholamines: Catecholamines include adrenaline, noradrenaline and small amounts of dopamine - these hormones are responsible for all the physiological characteristics of the stress response, the so called 'fight or flight' response. Adrenal glands produce hormones such as estrogen, progesterone, steroids, cortisol, and cortisone, and chemicals such as adrenalin (epinephrine), norepinephrine, and dopamine.

9.Identify the components of the heart conducting system. Describe how an electric charge spreads along the structures of this conducting system

The cardiac conduction system is a group of specialized cardiac muscle cells in the walls of the heart that send signals to the heart muscle causing it to contract. The main components of the cardiac conduction system are the SA node, AV node, bundle of His, bundle branches, and Purkinje fibers. The SA node is the heart's natural pacemaker. The SA node consists of a cluster of cells that are situated in the upper part of the wall of the right atrium (the right upper chamber of the heart). The electrical impulses are generated there. The SA node is also called the sinus node. The atrioventricular (AV) node is a part of the electrical conduction system of the heart that coordinates the top of the heart. It electrically connects atrial and ventricular chambers. The AV node is an area of specialized tissue between the atria and the ventricles of the heart, specifically in the posteroinferior region of the interatrial septum near the opening of the coronary sinus, which conducts the normal electrical impulse from the atria to the ventricles. The AV node is quite compact (~1 x 3 x 5 mm).It is located at the center of koch's triangle—a triangle enclosed by the septal leaflet of the tricuspid valve, the coronary sinus, and the membraneous part of the interatrial septum. The bundle of His is a collection of heart muscle cells specialized for electrical conduction that transmits the electrical impulses from the AV node (located between the atria and the ventricles) to the point of the apex of the fascicular branches via the bundle branches. The bundle branches, or Tawara branches, are offshoots of the bundle of His in the heart's ventricle. They play an integral role in the electrical conduction system of the heart by transmitting cardiac action potentials from the bundle of His to the Purkinje fibres. Purkinje fibers are a unique cardiac end-organ. Further histologic examination reveals that these fibers are split in atria and ventricles walls. The electrical origin of atrial Purkinje fibers arrives from the sinoatrial node.

3.Describe the structure, function and location of the follicles

The follicle plays a major role in the dual function of the ovary--oocyte maturation and release and steroidogenesis required for regulating its own growth and providing the proper environment in reproductive organs for the transport of gametes and nidation. Some aspects of how follicles attain their functional competence following a series of developmental changes are discussed. The presentation is based on data obtained mainly in rodents in which follicular development occurs postnatally. The peak activity of follicular growth occurs during the 1st week of life, but not until the 5th day is follicular development clearly dependent upon gonadotrophin stimulation. The formation of the theca layer and zona pellucida, differentiation of the vascular system and competence to respond to gonadotrophins are acquired during the 2nd week. FSH alone is primarily responsible for granulosa cell proliferation and the integrity of the granulosa cell membrane, but has little differential effect on steroidogenic enzymes. Synergism of FSH and LH promotes an enrichment of the theca layer, enhancement of vascular development and antrum formation, and induces a marked differential stimulation of 20alpha-hydroxysteroid dehydrogenase, aromatizing and cholesterol side-chain cleavage systems. The number of gonadotrophin receptors on granulosa and theca cells increases with follicular development. Steroids secreted by the ovary seem to modulate follicular growth, not only by effects upon FSH and LH release but also by a local influence within the ovary. A number of physiological events related to follicular function are explained according to these observations. Ovarian follicles are the basic units of female reproductive biology. Each of them contains a single oocyte (immature ovum or egg cell). These structures are periodically initiated to grow and develop, culminating in ovulation of usually a single competent oocyte in humans. They also consists of granulosa cells and theca of follicle. Oocyte[edit] Main article: Oocyte Once a month, one of the ovaries releases a mature egg (ovum), known as an oocyte. A follicle is an anatomical structure in which the primary oocyte develops. The nucleus of such an oocyte is called a germinal vesicle [4] (see picture). Cumulus oophorus Main article: Cumulus oophorus Cumulus oophorus is a cluster of cells (called cumulus cells) that surround the oocyte both in the ovarian follicle and after ovulation. Membrana granulosa Main article: Membrana granulosa It contains numerous granulosa cells. Granulosa cell Main article: Granulosa cell Granulosa cells or follicular cells are cells that surround the oocyte within the follicle; their numbers increase directly in response to heightened levels of circulating gonadotropins or decrease in response to testosterone. They also produce peptides involved in ovarian hormone synthesis regulation. Follicle-stimulating hormone (FSH) induces granulosa cells to express luteinizing hormone (LH) receptors on their surfaces; when circulating LH binds to these receptors, proliferation stops. Theca of follicle Main article: Theca of follicle The granulosa cells, in turn, are enclosed in a thin layer of extracellular matrix - the follicular basement membrane or basal lamina (fibro-vascular coat in picture). Outside the basal lamina, the layers theca interna and theca externa are found. In a larger perspective, the whole folliculogenesis from primordial to preovulatory follicle is located in the stage of meiosis I of ootidogenesis in oogenesis.

1.Describe the hormones produced by the pancreas. Include functions of those hormones.

The pancreas is a glandular organ in the digestive system and endocrine system of vertebrates. In humans, it is located in the abdominal cavity behind the stomach. It is an endocrine gland producing several important hormones, including insulin, glucagon, somatostatin, and pancreatic polypeptide which circulate in the blood. The pancreas is also a digestive organ, secreting pancreatic juice containing digestive enzymes that assist digestion and absorption of nutrients in the small intestine. These enzymes help to further break down the carbohydrates, proteins, and lipids in the chyme. Insulin-Insulin helps control blood glucose levels by signaling the liver and muscle and fat cells to take in glucose from the blood. Insulin therefore helps cells to take in glucose to be used for energy. If the body has sufficient energy, insulin signals the liver to take up glucose and store it as glycogen. Glucagon-The pancreas releases glucagon when the concentration of glucose in the bloodstream falls too low. Glucagon causes the liver to convert stored glycogen into glucose, which is released into the bloodstream. High blood-glucose levels stimulate the release of insulin. Somatostatin-Somatostatin is a hormone produced by many tissues in the body, principally in the nervous and digestive systems. It regulates a wide variety of physiological functions and inhibits the secretion of other hormones, the activity of the gastrointestinal tract and the rapid reproduction of normal and tumour cells.

9.Describe the absorption process of the colon

The small intestine must absorb massive quantities of water. A normal person or animal of similar size takes in roughly 1 to 2 liters of dietary fluid every day. On top of that, another 6 to 7 liters of fluid is received by the small intestine daily as secretions from salivary glands, stomach, pancreas, liver and the small intestine itself. By the time the ingesta enters the large intestine, approximately 80% of this fluid has been absorbed. Net movement of water across cell membranes always occurs by osmosis, and the fundamental concept needed to understand absorption in the small gut is that there is a tight coupling between water and solute absorption. Another way of saying this is that absorption of water is absolutely dependent on absorption of solutes, particularly sodium: Sodium is absorbed into the cell by several mechanisms, but chief among them is by cotransport with glucose and amino acids - this means that efficient sodium absorption is dependent on absorption of these organic solutes. Absorbed sodium is rapidly exported from the cell via sodium pumps - when a lot of sodium is entering the cell, a lot of sodium is pumped out of the cell, which establishes a high osmolarity in the small intercellular spaces between adjacent enterocytes. Water diffuses in response to the osmotic gradient established by sodium - in this case into the intercellular space. It seems that the bulk of the water absorption is transcellular, but some also diffuses through the tight junctions. Water, as well as sodium, then diffuses into capillary blood within the villus. Examine the animation above and consider the osmotic gradient between the lumen and the intercellular space (inside the villus). As sodium (green balls) is rapidly pumped out of the cell, it achieves very high concentration in the narrow space between enterocytes. The osmotic gradient is thus formed across apical cell membranes and their connecting junctional complexes. The arrow that appears denotes movement of water across the epithelium. Water is thus absorbed into the intercellular space by diffusion down an osmotic gradient. However, looking at the process as a whole, transport of water from lumen to blood is often against an osmotic gradient - this is important because it means that the intestine can absorb water into blood even when the osmolarity in the lumen is higher than osmolarity of blood. This ability is best explained by the "three compartment model" for absorption of water and, like many aspects of gut permeability, varies along the length of the gut. The proximal small intestine functions as a highly permeable mixing segment, and absorption of water is basically isotonic. That is, water is not absorbed until the ingesta has been diluted out to just above the osmolarity of blood. The ileum and especially the colon are able to absorb water against an osmotic gradient of several hundred milliosmols. General description of Na+ absorptive processes The human colon has a nominal mucosal surface area of about 2000 cm2,3 but in reality the total absorptive area is even greater because colonic crypt cells are capable of absorption as well as secretion. Although it is well established that the rates of colonic salt (Na+ plus Cl−) and water absorption are directly related,5 it is only recently that we have begun to appreciate the array of Na+absorptive processes present in human colon. These show considerable intrinsic segmental heterogeneity. This explains, at least in part, why the colon's capacity for sodium and water absorption in vivo is greater in the proximal (ascending) segment than in the distal (descending and sigmoid colon/rectum) segment.Several different active (transcellular) Na+ absorptive processes exist in human colon. It will become clear that segmental differences in the distribution and regulation of these processes play an important role in colonic Na+ salvage during periods of salt deprivation, in the presence of mucosal inflammation, and after surgical resection. ELECTROGENIC Na+ ABSORPTION Electrogenic Na+ absorption is present throughout the human colon.he hallmark of this process is the presence of Na+ channels located predominantly in the apical membrane of surface colonocytes, through which Na+ ions diffuse into the cell along a favourable electrochemical gradient. This gradient reflects the low intracellular Na+ concentration (<15 mM) and the negative intracellular electrical potential difference.Active extrusion of Na+ ions across the basolateral membrane is mediated by the ouabain sensitive electrogenic Na+ pump (Na+,K+-ATPase). Each pump cycle results in the extrusion of three Na+ ions in exchange for the basolateral uptake of two K+ ions, resulting in the net transfer of one positively charged (Na+) ion across the basolateral membrane (fig 1). As the potential difference across the basolateral membrane (negatively charged with respect to the serosal surface) exceeds that across the apical membrane (negatively charged with respect to the luminal surface), a substantial lumen negative transmucosal potential difference is normally present in healthy human colon in vivo and in vitro, which largely reflects electrogenic Na+transport.

6.Describe the major blood vessels of the cardiovascular system

The three types of blood vessels are the arteries, veins, and capillaries. *Arteries are the vessels that carry blood away from your heart to the different parts of your body *Veins carries non-oxygenated blood to the heart *Capillary tubes with very thin walls which join arteries to veins.

1.Identify the functions of the lymphatic system

To transport fluids back to blood and act as the bodies defense and resistance to disease.

2.Describe airflow from the atmosphere into the alveoli

Trace the flow of air from the nose to the pulmonary alveoli Nose-Nasal cavity-pharynx-larynx-trachea-carina-primary bronchus-secondary-bronchus-terminal-bronchus-respiratory bronchioles-alveoli

3.Describe Dalton's law, Boyle's law and Henry's Law

What is Boyle's law as the size of a closed container decreases, pressure inside is increased, and vice versa What is Dalton's Law Dalton's law of partial pressure: in a mixture of gasses, the total pressure is equal to the sum of pressures contributed by each individual gas What is Henry's law The amount of gas that will dissolve in a liquid (at a given temperature) is proportional to the partial pressure of the gas (in other words, more pressure = more dissolving into a liquid)

10.Identify the enzymes that digest carbohydrates, proteins, and lipids.

he small intestine is where most chemical digestion takes place. Most of the digestive enzymes in the small intestine are secreted by the pancreas and enter the small intestine via the pancreatic duct. These enzymes enter the small intestine in response to the hormone cholecystokinin, which is produced in response to the presence of nutrients. The hormone secretin also causes bicarbonate to be released into the small intestine from the pancreas, neutralizing the potentially harmful acid coming from the stomach. The three major classes of nutrients that undergo digestion are proteins, lipids (fats), and carbohydrates. Proteins Proteins are degraded into small peptides and amino acids before absorption. Chemical breakdown begins in the stomach and continues through the large intestine. Proteolytic enzymes, including trypsin and chymotrypsin, secreted by the pancreas, cleave proteins into smaller peptides. Carboxypeptidase, a pancreatic brush border enzyme, splits one amino acid at a time. Aminopeptidase and dipeptidase free the end amino acid products. Lipids Lipids (fats) are degraded into fatty acids and glycerol. Pancreatic lipase breaks down triglycerides into free fatty acids and monoglycerides. Pancreatic lipase works with the help of the salts from bile secreted by the liver and the gall bladder. Bile salts attach to triglycerides, helping emulsify them, which aids access by pancreatic lipase; the lipase is water-soluble, but the fatty triglycerides are hydrophobic, tending to orient toward each other and away from the watery intestinal surroundings. The bile salts act as the "main man" that holds the triglycerides in the watery surroundings until the lipase can break them into the smaller components that are able to enter the villi for absorption. Carbohydrates Some carbohydrates are degraded into simple sugars, or monosaccharides (e.g., glucose, galactose) and absorbed by the small intestine. Pancreatic amylase breaks down some carbohydrates (notably starch) into oligosaccharides. Other carbohydrates pass undigested into the large intestine, where they are digested by intestinal bacteria. Brush border enzymes take over from there. The most important brush border enzymes are dextrinase and glucoamylase, which further break down oligosaccharides. Other brush border enzymes are maltase, sucrase, and lactase. Lactase is absent in most adult humans and for them lactose, like most poly-saccharides, is not digested in the small intestine. Some carbohydrates, such as cellulose, are not digested at all, despite being made of multiple glucose units. This is because the cellulose is made out of beta-glucose, making the inter-monosaccharidal bindings different from the ones present in starch, which consists of alpha-glucose. Humans lack the enzyme for splitting the beta-glucose-bonds—reserved for herbivores and bacteria in the large intestine.

4.Define metabolism, anabolism, and catabolism

metabolism All chemical reactions in an organism anabolism builds up reactions requiring energy and building blocks catabolism breaks down reactions gaining energy and building blocks

1.Identify the functions of the respiratory system

to supply the body with oxygen and dispose of carbon dioxide

3.Differentiate between the structures of the digestive tract and the accessory structures

• The alimentary canal, or GI tract, is the continuous muscular digestive tube that winds through the body digesting and absorbing foodstuff; its organs include: the mouth, pharynx, esophagus, stomach, small intestine, and large intestine. • Accessory digestive organs or structures aid digestion physically and produce secretions that break down foodstuff in the GI tract; the organs involved are the teeth, tongue, gallbladder, salivary glands, liver and pancreas.

7.Identify the factors that affect blood pressure

• peripheral resistance • vessel elasticity • blood volume • cardiac output Peripheral resistance-Peripheral resistance is the resistance of the arteries to blood flow. As the arteries constrict, the resistance increases and as they dilate, resistance decreases. Peripheral resistance is determined by three factors: Autonomic activity: sympathetic activity constricts peripheral arteries. Vessel elasticity-The condition or property of being elastic; flexibility Blood volume-is the volume of blood (both red blood cells and plasma) in the circulatory system of any individual. Cardiac output-Cardiac output is the volume of blood pumped by the heart per minute (mL blood/min). Cardiac output is a function of heart rate and stroke volume. The heart rate is simply the number of heart beats per minute. The stroke volume is the volume of blood, in milliliters (mL), pumped out of the heart with each beat. Increases in peripheral resistance, blood volume, and cardiac output result in higher blood pressure. Conversely decreases in any of these factors lead to lower blood pressure. Three main sources of peripheral resistance: Blood vessel diameter, blood viscosity, and total vessel length.