Course Grades

Course Materials

NOTE: Answers are located on the bottom of each page

There are various organs of excretion in the body; the two main excretory organs of the urinary system are known as the 1 . Two functions of the kidneys are to 2 and to 3 .

4 liters of blood flow through the renal artery per minute,

5 liter of which enters each kidney. The 6 are tubes leading from the kidneys to the bladder. These tubes are wrapped in 7 which cause 8 waves; these waves sweep the urine downward into the urinary bladder. The urinary bladder stores urine. Periodically, the muscular walls of the urinary bladder contract and expel the urine from the body through a duct called the 9 .

Each kidney consists of three large structural parts: the 10 comprises the outer area, the 11 is the hollow area into which the nephrons dump waste fluids, and the 12 comprises the total area between the outer layer and the hollow area. The kidneys are covered at their surface by a thick layer of connective tissue called the 13 . The kidneys receive systemic blood from branches of the aorta called 14 , and blood leaving the kidneys enters the inferior vena cava through the 15 .

Each kidney has about 1 million microscopic structures called 16 which are the sites where blood filtration occurs. The nephron is composed of many parts. The nephron's capillary bed is called the 17 . Each nephron has its own blood supply: systemic blood from the renal artery leads into the glomerulus through a(n) 18 arteriole and exits out of the glomerulus through a(n) 19 arteriole. A cup-shaped structure called 20 surrounds the glomerulus. Extending out from this capsule is a long tube, the different parts of which have different names according to their location and shape. The part nearest to the Bowman's capsule is known as the 21 tubule. Toward the end of the proximal convoluted tubule, the tube straightens out, dips down, makes a U-turn, and heads back up again, forming a loop-like shape referred to as the 22 . The part of the loop that heads downward is known as the 23 loop; the part that goes upward is known as the 24 loop. The tube then begins to twist and wind again; this part is called the 25 tubule. The distal convoluted tubule of the nephron merges with an end site known as a 26 which is shared by a few neighboring nephrons.


1. kidneys 2. regulate fluid balance 3. rid body of wastes

4. 5-6 5. 1/2 6. ureters 7. smooth muscles 8. peristaltic

9. urethra 10. renal cortex 11. renal pelvis 12. renal medulla 13.renal capsule 14.renal arteries 15.renal veins 16.nephrons 17. glomerulus 18. afferent 19. efferent 20. Bowman's capsule 21. proximal convoluted (PCT) 22. loop of Henle 23. descending 24. ascending 25. distal convoluted (DCT) 26. collecting duct


The efferent arteriole that exits the glomerulus of the nephron gives rise to a second capillary network called the 1 that weaves around the proximal convoluted tubule, loop of Henle, and the distal convoluted tubule. This capillary network, also known as the vasa recta, forms into the 2 which takes blood away from the kidneys.

Inside the capillary walls of the glomeruli (plural of glomerulus), there is a net pressure gradient of 20 hydrostatic (blood) pressure forcing fluid through the capillary walls; this is called the 3 and it is uniform over the entire length of the glomerular capillary network. The maintenance of high blood pressure in the glomerular capillaries is due in part to the differential sizes of 4 . The afferent arterioles which conduct blood into the glomeruli are relatively 5 in comparison to the efferent arterioles, which conduct the blood away from the glomeruli. This is an important point, and the reason for having two arterioles: to keep blood pressure up and thus force the filtration of fluids. (Inside the Bowman's capsule there is hydrostatic pressure which opposes the glomerular filtration pressure; however, because the glomerular filtration pressure is greater, the fluid moves from the glomerulus into the Bowman's capsule.)

The capillary walls and the walls of the Bowman's capsule are highly porous; each is formed by a single, thin layer of 6 cells. Most small molecules in the blood are filtered; 7 and 8 , however, are not. The glomerular filtration rate (GFR) for all the glomeruli in both kidneys is approximately 9 ml/min., or 10 liters/day. All the fluid that gets filtered through the glomerulus is called 11 ; this filtrate passes from the Bowman's capsule to the 12 . The blood leaving the glomerulus (not filtered) goes through the efferent arteriole and enters the 13 . The filtrate and the blood here are therefore separated by two layers of cells only: the epithelial wall of the PCT and the lining of the capillaries. REMEMBER: everything gets filtered through the glomerulus except for blood cells and plasma proteins; therefore, all the plasma in the blood (minus the plasma proteins) eventually gets filtered. The term tubular reabsorption is used to refer to the filtrate that goes into the 14 ; the term tubular secretion is used to refer to the filtrate that goes into the 15 .

1. peritubular capillary network 2. renal vein 3. glomerular filtration pressure 4. the arteriole that enters the glomerulus and the arteriole that exits it 5. wide 6.epithelial 7. plasma proteins 8. red and white blood cells 9. 125 10. 180

11. ultrafiltrate 12.proximal convoluted tubule 13. peritubular capillary network 14. body 15. collecting duct


OSMOLARITY - When fluid contains 300 particles per liter, it is said to be 1 . Anything containing fewer than 300 particles per liter is called 2 , and anything containing more than 300 particles per liter is called 3 . There are two ways in which the osmolarity of a fluid can change: the addition or removal of 4 or the addition or removal of 5 .

The concentration of filtrate going into and coming out of the glomerulus is about 6 mOsm/L; therefore, it is said to be 7 . In the proximal convoluted tubule (PCT), sodium and glucose are pumped 8 ; therefore, the osmolarity in the PCT goes 9 . This process is known as 10 transport. (These pumps are the reason normal people do not lose sugars and amino acids through their urine.) Because of the 11 outside, water from inside the PCT flows passively into the blood of the peritubular capillaries. There is a steadily increasing osmotic pressure that exists outside the loop of Henle; this pressure starts at about 12 mOsm/L at the end of the PCT and the beginning of the descending loop, increasing in concentration to approximately 13 mOsm/L. This steadily increasing rise in osmolarity causes water to flow out of the loop of Henle and be reabsorbed. Approximately 14 percent of the filtrate (144 liters) is reabsorbed into the body this way, a mechanism known as 15 reabsorption because it is in response to pressure gradients over which the body does not exercise much control. Of this percentage, approximately 60% is reabsorbed from the PCT and 20% is reabsorbed from the descending loop.

In the ascending loop of Henle there are many ion pumps. The walls of this part of the loop are very thick and they do not allow 16 to pass through. Because the water remains trapped inside the ascending loop of Henle while the ions are being pumped out, the osmolarity of the filtrate inside becomes increasingly 17 as you ascend further and further up the loop. At the top of the ascending loop of Henle about 18 liters of very dilute fluid remain with an osmolarity of approximately 19 .


1. iso-osmotic 2. hypo-osmotic 3. hyper-osmotic 4. water

5. particles 6. 300 7. iso-osmotic 8. out 9. down 10. active 11. osmotic gradient 12. 300 13. 1200 14. 80 15. mandatory reabsorption 16. water 17. lower 18. 36 19. 100


The walls of the distal convoluted tubule (DCT) are 1 to water; thus, it is in the 2 that the rest of the water reabsorption occurs, this time via facilitated reabsorption. 3 is the hormone responsible for the regulation of water reabsorption from the collecting duct. It is produced in the 4 gland. When ADH hooks to the collecting duct, the collecting duct becomes 5 to water and water flows 6 the collecting duct via osmosis. The net effect of this is 7 water in the urine.

Humans don't feel thirsty until they are about 8 percent dehydrated. When we are drinking large amounts of water, the osmolarity of the blood will decrease. This is sensed by the hypothalamus, which causes the pituitary's ADH production to 9 ; when this happens, the walls of the collecting duct become 10 to water. Remember, the osmolarity of plasma goes 11 after drinking water, and does the opposite when we do not drink water. When ADH production goes down, the volume of water in the urine goes 12 , causing the urine to be 13 -colored. When the osmolarity of urine is at its maximum, approximately 1200, the color of the urine is 14 because it is highly concentrated.

Only 15 cc. of filtrate are produced for each liter of blood that passes through the kidneys. Most of the waste products in the blood aren't filtered into the Bowman's capsule; rather, they pass with the blood from the glomerular capillaries into the peritubular capillaries. These wastes are put into the tubules directly via active transport, a process known as 16 .

A human's normal urine flow is about 17 liters per day. A product that is a constant component of urine is 18 , a waste product from the breakdown of protein. 19 is a condition characterized by protein in the urine. The bladder can typically expand up to 400 ml before a person feels the need to urinate. The expansion of the bladder causes the 20 to relax, but urine is not expelled until a person consciously relaxes the 21 .

REGULATION OF BLOOD PH - The optimal Ph level for blood is 22 . The Ph of urine can range from 23 to 24 . In each cell, there is a substance called 25 that hydrates carbon (CO2 + H2O = H2CO3). 26 is an acid and 27 is a base. If the blood is acidic, acid (hydrogen) goes to the collecting duct and out of the kidney into the urine, and the base (HCO3) gets added to the blood, via the vasa recta. If the blood is alkaline (basic), the opposite occurs.


1.impermeable 2. collecting duct 3. anti-diuretic hormone (ADH) 4. pituitary 5. permeable 6. out of 7. less 8. two 9. slow down 10. impermeable 11. down 12. up 13. clear 14. orange 15. 100 16.tubular secretion 17. 1.5 18. urea 19. Proteinuria 20.internal sphincter muscle 21.external sphincter muscle 22.7.4 23. 3 24. 10 25. carbonic anhydrase 26. Hydrogen 27. HCO3


The kidneys also regulate blood pressure. The 1 , located where the DCT fuses with the wall of the afferent arteriole, senses the amount of flow going through the nephron. A reduction in filtration rate is caused by, and is an indicator of, lowered 2 . When the juxtaglomerular apparatus senses this decrease in flow, the kidneys release 3 into the bloodstream. Through a series of chemical changes, renin causes 4 to be made, and this causes blood vessels to 5 . In addition to causing vasoconstriction, angiotensin II hooks onto the 6 , causing them to secrete a hormone called 7 . This hormone causes a higher 8 reabsorption. Water and Cl- follow sodium passively, thus causing an increase of fluid in the blood. The actual mechanism is as follows: sodium, water and chloride are taken up by the 9 , which then put them back into the bloodstream via the 10 which dumps into the 11 . Note that the sodium is reabsorbed through active transport; angiotensin II causes sodium pumps to pump faster. Water follows passively behind due to osmosis. To summarize, angiotensin II causes an increase in blood pressure in two ways. It causes constriction of blood vessels, and it stimulates sodium pumps indirectly; this increases blood flow, and therefore, blood pressure.

The cells of the glomerulus sense two things in arterial blood: 12 and 13 . If either of these is detected, a hormone called 14 is released which goes to the bone marrow and causes two things to happen: 15 and 16 . In summary, in addition to ridding the body of wastes and filtering the blood, the kidneys regulate 17 , cause an increase in the production of 18 , and control the 19 level of the blood.

In the procedure known as 20 , used with people whose kidneys don't function properly, blood passes through a series of cellophane sheets that are permeable to everything but plasma proteins and blood cells.


1. juxtaglomerular apparatus (JGA) 2. blood pressure 3. renin

4. angiotensin II 5. vasoconstrict 6. adrenal glands

7. aldosterone 8. sodium 9. vasa recta, a.k.a. peritubular capillaries 10. renal vein 11. inferior vena cava 12. hypoxia (or low blood oxygen) 13. hypovolemia (or low blood volume)

14. erythropoietin 15. more red blood cells to be produced

16. the release of any newly-formed red blood cells from the bone marrow 17. blood pressure 18. red blood cells 19. Ph

20. hemodialysis

1 is the study of hormones, substances produced in one area that affect another area. An example is ADH that is produced in the 2 gland of the central nervous system and works on the 3 of the kidneys.

Glucagon, produced by 4 cells, and insulin, produced by

5 cells are examples of 6 hormones, that is, their actions oppose each other. These hormones are released by the 7 .

Glucose is the major source of fuel for cells in the 8 . (Muscles have three different fuel sources: fats, glucose, and protein.) Glucose can be made into energy immediately or can be stored as 9 , a compound of 2,000-10,000 glucose units hooked together. Muscles store carbohydrates (glucose), but by far the largest store of glucose (in the form of glycogen) is found in the 10 . Under resting conditions, most human cells other than cells of the CNS (nerve cells) are impermeable to glucose. 11 makes cells permeable to glucose. When the cells are permeable to glucose, the blood glucose level 12 . The hormone 13 makes the blood glucose level go up by breaking down liver glycogen; the resulting glucose goes into the bloodstream. After we eat, blood glucose begins to go up. This causes 14 to be released and hook onto cell membranes, thus allowing entry of 15 into the cells. This causes blood glucose levels to decline. The major stimulus for insulin to be released is 16 . After glucose enters the cells and the blood glucose level drops, the blood glucose levels off again because the drop causes the release of 17 , which, as mentioned earlier, targets the liver, cleaving off liver glycogen to be released into the bloodstream as glucose.

Resting glucose levels are 80-100 mg. per deciliter. A condition in which the blood glucose level drops to 50-60 mg/dl is known as 18 ; a condition in which the blood glucose level is higher than normal (110-130 mg/dl) is called 19 . Symptoms of hypoglycemia (commonly known as low blood sugar) include headaches, blurred vision, fatigue, and shaking. 20 can occur very rapidly with immediate dangerous effects whereas the effects of 21 occur more slowly, accumulating over time.

Juvenile onset, or 22 diabetes, has an onset early in life and accounts for about 10% of the total cases of diabetes in our country. The other 90% of diabetics are 23 diabetics, also known as adult onset diabetes because it usually emerges after 18 years of age.


1. Endocrinology 2. pituitary 3. collecting ducts 4. alpha

5. beta 6. antagonistic 7. pancreas 8. central nervous system (CNS) 9. glycogen 10. liver 11.Insulin 12. drops 13. glucagon 14. insulin 15. glucose 16. an increase in the blood glucose level 17. glucagon 18. hypoglycemia 19. hyperglycemia

20. Hypoglycemia 21. hyperglycemia 22. Type I 23. Type II


With Type I diabetes, 1 is not being produced; therefore, no glucose gets into cells. Blood glucose levels are 3-6 times higher. One of the problems is with the kidneys: glucose is freely filtered and reabsorbed, but the glomeruli can only handle about 250 ml/dl. This is the reason why diabetics have a high glucose level in their urine. These high levels of blood glucose destroy organs over time and the life expectancy of juvenile diabetics is 2 that of a normal life expectancy. The treatment of Type I diabetes is 3 replacement, injected subcutaneously about 2 times per day. When too much insulin is taken, the person goes into 4 caused by the resulting sudden drop in blood glucose. To counteract this drop, the person must immediately ingest sugar (candy, orange juice, etc.). Currently, human insulin is synthetically produced, but research is directed at transplanting 5 cells into the pancreas. With Type II diabetes, the 6 do not respond well to insulin. One of the main factors associated with this condition is 7 ; therefore, one of the recommended treatments is to 8 . Another treatment includes 9 because this causes more glucose to be put into cells.

METABOLISM - The only biological energy source that we can use is 10 . We need this energy for contraction of muscles for movement, to work sodium potassium pumps, and to contract the diaphragm and heart muscles, among many other things. Humans have very little of this energy source inside individual cells. When one of the bonds of ATP breaks, ATP becomes ADP (adenosine diphosphate) plus energy. The bond of ATP gets broken and remade into ATP again every six seconds. A ten-step process known as 11 takes C6 H12 O6 (carbohydrate) and converts it into 12 , which is made up of two three-carbon bonds. This is a very rapid process which can be done 13 , producing 2 ATP. Pyruvic acid can be used in two ways: it can be converted into 14 (when blood flow is cut off and no oxygen is present), or it can be used in the sub-cellular, two-membrane structures known as 15 (when oxygen is available) to produce more energy. Inside the mitochondria, pyruvic acid and fats are broken down into energy aerobically via a process known as the 16 , the first step of which is called 17 . During this cycle, 18 ions get passed over cytochromes via a mechanism known as the 19 . The free hydrogen ions hook up with 20 molecules and exit the cell as 21 . The free carbon molecules hook up to oxygen and leave the cell as 22 . The 23 and 24 muscles have large amounts of mitochondria. 25 is a substance that shuts off the aerobic production of energy.


1. insulin 2. two-thirds 3. insulin 4. insulin shock 5. beta 6. insulin receptors on cell membranes 7. obesity 8. lose weight 9. exercise 10. adenosine triphosphate (ATP)

11. glycolysis 12. pyruvic acid 13. anaerobically 14. lactic acid 15. mitochondria 16. citric acid cycle 17.acetyl-Co-A 18. hydrogen 19. electron transport system (ETS) 20. oxygen 21. water (H2O) 22. carbon dioxide (C02) 23.heart 24.diaphragm 25. Cyanide


The chemical compound of fats is C16 H32 O2. An example of fat is palmitic acid. In the mitochondria, the body breaks fats into 1 units, making a total of eight C2 units. These units are called 2 . We get about 3 of our energy from fats and 4 from carbohydrates. Neurons get their energy from 5 , whereas other cells use 6 first, reserving 7 for when energy is needed fast. 8 tissues are tissues that store a lot of fat. The role of fat is to supply an extra energy source aerobically. The process of fats being used for energy is called 9 . Fats go directly into the 10 as acetyl-Co-A. The advantage of fats is that they yield a great amount of energy per gram. The disadvantages of fats are that they cannot be used without 11 and cannot be converted into 12 . One 13 represents the energy needed to heat one liter of water to 1 degree Celsius. There are 14 Kcal in 1 gram of protein, 15 Kcal in 1 gram of carbohydrate, and 16 Kcal in 1 gram of fat. The energy balance is equal to Kcal in minus Kcal out. (+/- 3500 Kcal = +/- one pound). We have a limited capacity to store carbohydrates and proteins; therefore, when we're in a positive caloric balance (i.e. we eat more than we use) food gets converted to 17 and then gets backtracked and made into fat. This process is called 18 .

New glucose can be made from proteins, a process known as 19 . In this process, proteins get broken down into pyruvic acid, which can then be made into 20 , by a reversal of the glycolysis process. Sixty percent of our carbohydrates are stored in the liver as liver glycogen, giving the human body a 21 hour supply. When the liver glycogen supply starts to run out, the 22 process kicks in, converting protein into pyruvic acid and then into carbohydrates. The price a person would pay after getting energy in this way for a prolonged period of time would be 23 . That's why when people starve themselves, the cause of death is often either 24 failure or 25 failure--the muscles can no longer do their job. When a person wants to lose weight, it is important to 26 more in addition to eating less in order to lose 27 rather than 28 .


1. 2-carbon units 2.acetyl-Co-A 3. 2/3 4. 1/3 5. glucose (carbohydrates) 6.fats 7.carbohydrates 8. Adipose 9. beta oxidation 10. mitochondria 11. oxygen 12.carbohydrates

13. calorie 14. 4 15. 4 16. 9 17. acetyl-Co-A 18. lipogenesis 19.gluconeogenesis 20.carbohydrates 21. 24-48 22.gluconeogenesis 23. muscular atrophy 24. respiratory 25. heart 26. exercise 27. fat 28. muscle


1 fats are solid at room temperature; these fats have hydrogen ions on all their bonding sites. When a fat is 2 , there are some bonding sites that are empty. The process known as 3 adds hydrogen to fats that are not saturated. The American Heart Association recommends that 4 percent or less of an individual's caloric intake be fat; of this, only 5 percent should be saturated and the remaining 6 percent should be unsaturated. Saturated fats are worse than cholesterol because they are three times more likely to cause 7 .

8 percent of the calories we consume is used as energy; the remaining 9 percent is given off as heat. The core temperature (or inside temperature) of humans is about 10 degrees C. This temperature can fluctuate within a range of approximately nine degrees: 32 degrees C.(low end) to 37 degrees C.(normal) to 41 degrees C.(high end). Factors that impact on our core temperature are 11 and 12 .

Human beings are 13 , that is, they control their core temperature physiologically. Conversely, 14 must lower or raise their core temperature using behavioral means. There are two ways that humans lose heat (i.e. cool off). 15 , in which high heat moves to low heat, is temperature dependent. We cool off this way about 16 percent of the time. The other method that we use to cool off (90% of the time) is 17 ; this method is 18 dependent, and is one of the reasons why water is so important to humans.

Humans have 2-4 million sweat glands composed of two parts: the 19 and the 20 . Relative humidity in the atmosphere can range from 0 to 100 percent. At 100%, the air is completely saturated with 21 . The evaporation of water--water changing from a liquid into a gas--takes energy. The coil of a sweat gland is really a 22 . At this site, Na+ and Cl- are actively pumped in and 23 follows passively. The duct is double-layered and lined with 24 that pump a large amount of these ions back into the body rather than allowing them to be lost in perspiration.


1. Saturated 2. unsaturated 3. hydrogenation 4. 30 5. 10

6. 20 7. plaque buildup 8. Twenty-five 9. 75 10. 37

11. eating 12. the environment 13. homeotherms 14. heterotherms 15. Convection 16. 10% 17. evaporation 18. humidity 19. coil 20. duct 21. water vapor 22. capillary bed 23. water

24. sodium chloride pumps


Water cannot passively follow the ions that are actively being pumped out of the ducts of the sweat glands because 1 ; therefore, water molecules go to the skin's surface. (Note: Some of the ions leak out with the perspiration, but the osmolarity is reduced from 300 in the capillary bed to between 50-150 in perspiration.) Sweating is controlled by the temperature regulation system in the 2 which sends messages to the coils of the sweat glands via the release of the neurotransmitter 3 , which innervates the pumps.

There are a few ways in which humans can heat their core temperature: 4 (when body hairs stand up), 5 at the periphery of the body and 6 . Shivering generates heat because 75% of the energy used in this muscle movement comes off as heat. Shivering requires great amounts of 7 . These mechanisms work on a 8 . If our core temperature goes over 37 degrees C, we 9 and 10 until we cool off. If it goes under 37, we 11 and 12 until we warm up. When we have a fever, substances known as 13 alter the set point to a higher level. When a fever breaks, the body sweats and the vessels vasodilate in an attempt to cool down because the pyrogens are gone and the set point has readjusted to normal (back down to 37). The reason aspirin brings down a fever is because it alters the 14 back down toward normal. Becoming overheated can be dangerous; for example, 15 is the biggest killer of high school athletes.

THE GASTROINTESTINAL TRACT - The G.I. tract has two functions: 16 and 17 . Different enzymes work to break down different substances in our bodies: 18 works to break carbohydrates down into glucose, 19 works to break fats down into free fatty acids, and 20 works to break proteins down into amino acids. Approximately 2 liters of saliva go into the mouth every day. In addition to water, saliva contains 21 , which immediately begins to break down carbohydrates, 22 , which coats the food that is broken down, and 23 , a buffer, which modifies the acidity of food and thus protects calcium on teeth. Swallowing results from the tongue contracting and closing up the mouth, squeezing the food back. During swallowing, the 24 rises up and hits the cartilage tissue known as the 25 , thus closing off the air passage. The smooth muscle of the 26 then relaxes, causing food to enter into it. The smooth muscles of the esophagus push the food down toward the stomach in 27 waves.


1. the duct walls are not permeable to H2O molecules

2. hypothalamus 3. acetylcholine (ACh) 4. piloerection

5.vasoconstriction 6.shivering 7.carbohydrates 8.hypothalamic set-point 9.sweat 10. vasodilate 11. shiver 12. vasoconstrict 13. pyrogens 14.set-point 15. heat injury 16. to enzymatically break foodstuffs down into units 17. to put these units into the blood to go to the cells 18. amylase 19. lipase 20. peptidase 21. amylase 22. mucus 23. HCO3 24. larynx 25. epiglottis

26. esophagus 27. peristaltic


At the beginning of the stomach is the 1 sphincter; at the end point of the stomach just before the small intestine begins is the 2 sphincter. The stomach's Ph level is about 3 , which is a very hostile environment, thus killing many microorganisms. The stomach is lined with 4 to protect it from its own acidic environment. Ulcers occur in the stomach when the stomach is not properly lined. Ulcers also occur in the esophagus, but by far the largest number of ulcers occurs in the 5 . Three solutions are secreted into the stomach. They are 6 . Pepsin is stored in cells as 7 . 8 activates pepsinogen and turns it into pepsin, which breaks down proteins. The stomach churns and mixes food with pepsin, turning it into 9 . Note: People who suffer from chronic acid indigestion often take alkaline solutions (buffers) that neutralize stomach acid. However, too much neutralization of the stomach environment will interfere with pepsinogen activation (too little HCl) thus causing a deficit in pepsin and an inability to break down proteins.

The small intestine is bigger in 10 but smaller in 11 than the large intestine. The small intestine is between 12 feet long and 13 inch(es) in diameter. The large intestine is about 14 feet long and 15 inch(es) in diameter. The first 12 inches of the small intestine is known as the 16 . Approximately 17 liters of fluid are secreted into the duodenum per day by the liver, pancreas and gall bladder via the 18 . The pancreas produces 19 , 20 , and 21 , and secretes them into the duodenum. The liver produces 22 constantly and stores it in the 23 . 24 are caused by bile that is too concentrated. Bile emulsifies 25 (breaks them down into smaller pieces); the gall bladder secretes the bile into the duodenum when it is needed. After the fats are emulsified, thus increasing their surface area, the enzyme 26 can break them down into free fatty acids.


1. cardiac 2. pyloric 3. 1-2 4. thick mucus 5. duodenum

6. HCl (hydrochloric acid), mucus, and enzymes (pepsin)

7. pepsinogen 8. HCl 9. chyme 10. length 11. diameter

12. 10-15 13. 1/2 14. 2-3 15. 2-3 16. duodenum 17. 10

18. common bile duct 19. HCO3 (bicarbonate) 20. amylase

21. lipase 22. bile 23. gall bladder 24. Gall stones

25. fats 26. lipase


The small intestine is lined with finger-like projections called 1 which increase its surface area by 600. Surrounding the villi are 2 and 3 . The broken down proteins (amino acids) and carbohydrates (simple sugars, i.e., glucose) are pumped into the 4 by pumps along the villi. The broken down fats (free fatty acids) are taken up by the 5 whose vessels dump them into the 6 . This is the reason why the heart takes the brunt of a high fat diet; it's the first organ of the body to see fats. Blood leaving the small intestine (containing the newly-absorbed amino acids and glucose) goes first to the 7 via the 8 . This gives the liver priority for maintaining its glycogen supply. The liver dumps blood into the hepatic vein which then gets dumped into the 9 . The 10 supplies the liver with oxygenated blood.

11 percent (approximately 10 L) of water reabsorption occurs in the small intestine. Pumps in the villi of the small intestine pump 12 out and water molecules follow passively via osmosis. The 13 is located close to where the small and large intestines meet.

The biggest role of the large intestine is to reabsorb 14 and 15 . 16 is a disease that causes much greater amounts of water to accumulate in the large intestine; this causes diarrhea and the loss of large amounts of sodium.

EXERCISE PHYSIOLOGY - Athletes typically have larger 17 ; therefore, they have greater 18 and greater 19 intake per minute. Athletes also have more 20 in their cells, gained through extensive training.


1. villi 2. lymph ducts 3. capillaries 4. capillary network 5. lymph ducts 6. superior vena cava 7. liver 8. hepatic portal vein 9. superior vena cava 10. hepatic artery

11. Eighty 12. sodium 13. appendix 14. sodium 15. water

16. Cholera 17. hearts 18. cardiac output 19. oxygen (VO2) 20. mitochondria