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DEPARTMENT OF CHEMISTRY AND LIFE SCIENCE CH387, Human Physiology, AY07-2 Written Partial Review 3 (E hour) 23 April 2007 Available time: 55 minutes Resources Permitted: None TEXT: Germann & Stansfield, Principles of Human Physiology, 2nd Edition SCOPE: Lessons 24-33
CHECK THIS EXAMINATION TO SEE THAT THERE ARE 7 PAGES. INFORM THE INSTRUCTOR OF ANY INCOMPLETE OR MISSING PAGES. WRITE YOUR NAME ON THE TOP OF EACH SHEET. ANSWER ALL QUESTIONS.
TOTAL WEIGHT 200 POINTS
DO NOT WRITE IN THIS SPACE:
PART 1 2 TOTAL
MAX VALUE 120 80 200
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PART 1 (120 Points) MULTIPLE CHOICE: (4 points each) 1. (1) The ________ functions primarily as the region of the lungs where the majority of gas exchange occurs. a. b. c. d. respiratory bronchiole alveolar duct alveolus terminal bronchiole
2. (1) An increase in renal reabsorption of a substance will _______ its excretion. a. increase b. decrease c. not change 3. (2) What type of cells secrete mucus in the respiratory tract? a. b. c. d. e. goblet cells type I alveolar cells type II alveolar cells ciliated cells macrophages
4. (3) When air is no longer moving through the respiratory tract and the airway is open to the environment, the pressure within the lung is equal to _______________. a. b. c. d. transpulmonary pressure atmospheric pressure intrapleural pressure systolic blood pressure
5. (1) A measure of the distending force across the lungs is the _________________. a. b. c. d. intrapleural pressure intra-alveolar pressure transpulmonary pressure atmospheric pressure
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6. (3) As the lungs expand, intra-alveolar pressure _______ and air moves ________ the lungs. a. b. c. d. decreases : into decreases : out of increases : into increases : out of
7. (3) As the resistance of the airway increases, __________ would be required to move the same volume of air into the lung. a. b. c. d. an enhanced lung compliance a greater transpulmonary pressure a reduction in lung compliance a reduction in surface tension
8. (3) The compensation for metabolic acidosis is a. b. c. d. decreased ventilation, increased HCO3 reabsorption, and decreased H+ secretion. increased ventilation, decreased HCO3 reabsorption, and decreased H+ secretion. decreased ventilation, decreased HCO3 reabsorption, and increased H+ secretion. increased ventilation, increased HCO3 reabsorption, and increased H+ secretion.
9. (2) The surface tension of the alveolus is reduced by surfactants produced by the ____ cells. a. b. c. d. ciliated goblet type I alveolar type II alveolar
10. (1) __________ cells function to secrete hydrogen ions into the lumen of the stomach. a. b. c. d. Parietal Neck Goblet Chief
11. (2) The volume of the respiratory pathway that is not able to exchange gases (conducting pathway) is referred to as ________________. a. b. c. d. dead volume anatomical dead space residual volume functional residual volume
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12. (2) Which of the following is NOT a normal function of the high acidity of the stomach? a. b. c. d. activate vitamin B12 activate pepsin denature proteins destroy foodborne bacteria
13. (2) Which of the following can increase the concentration of a particular gas in a solution? a. b. c. d. increase in partial pressure of that gas exposed to the solution increase the volume of the container containing the gas and solution increase the volume of the gas only increase the volume of the solution only
14. (1) The relationship between the concentration of a gas in solution and the partial pressure of that gas can be described by ________________. a. b. c. d. Boyle's Law Fick's Law Dalton's Law Henry's Law
15. (1) Hypoventilation would lead to a(n) _____________ within the systemic arteries. a. b. c. d. decrease in PO2 and increase in PCO2 increase in PO2 and decrease in PCO2 increase in both PO2 and PCO2 decrease in both PO2 and PCO2
16. (1) The majority of oxygen present within the blood is ________. a. b. c. d. in the plasma as HCO3dissolved within the plasma bound to hemoglobin within the plasma bound to hemoglobin in red blood cells
17. (3) The buffering capacity of hemoglobin is directly related to its ability to bind with _____. a. b. c. d. carbon monoxide carbon dioxide oxygen hydrogen ions
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18. (1) Severe vomiting can cause a metabolic alkalosis by an increased _____________. a. b. c. d. production of bicarbonate loss of hydrogen ions loss of phosphate production of hydrogen ions
19. (1) In the passive reabsorption of urea, its concentration gradient across the tubule is maintained by coupling its movement to the movement of ____________. a. b. c. d. chloride potassium water bicarbonate
20. (2) The cellular changes induced by aldosterone will result in a(n) ____________. a. b. c. d. e. decreased plasma osmolarity decreased blood pressure increased sodium secretion increased potassium secretion all of the above
21. (3) During what process are molecules selectively removed from the tubule lumen, moved into the interstitial space, and removed from the kidneys by the peritubular capillaries and the vasa recta? a. b. c. d. reabsorption absorption excretion filtration
22. (1) Antidiuretic hormone (ADH) is released from the ___________. a. b. c. d. collecting duct pancreas distal tubule posterior pituitary
23. (2) The primary function of the kidneys involves regulating the _________ and the ________ of plasma and interstitial fluid. a. b. c. d. volume : temperature volume : composition temperature : composition pressure : volume
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24. (1) When free of the gravitational effect, astronauts experience "fluid shift" which can cause _______________. a. b. c. d. motion sickness muscular atrophy bone loss water loss
25. (1) Which of the following secretes lipase? a. b. c. d. pancreas salivary glands liver both A and B
26. (3) The digestion of proteins begins in the ____________ with the activation of the zymogen ___________. a. b. d. c. e. small intestine : trypsinogen stomach : pepsinogen mouth : pepsinogen small intestine : chymotrypsinogen stomach : procarboxypeptidase
27. (2) Once the chyme begins to enter the duodenum, it must first be ________ before any of the enzymes in the pancreatic juice can be activated. a. b. c. d. acidified dehydrated neutralized phosphorylated
28. (2) As food is broken down into smaller pieces in the mouth, it is combined with _________ that facilitates its movement down the esophagus. a. b. c. d. saliva gastric juices chyme amylase
29. (1) _______ are enzymes secreted by the pancreas to digest fats. a. b. c. d. Amylases Nucleases Proteases Lipases
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30. (1) Which of the following secretes a bicarbonate-rich fluid? a. b. c. d. e. salivary glands pancreas liver both A and B all of the above
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PART 2 (80 Points) (20 points) Describe what causes metabolic acidosis and metabolic alkalosis and the renal compensation for these conditions. Metabolic acidosis caused by an increase in acids in the plasma from sources other than carbon dioxide (diarrhea causes loss of bicarbonate ion; diabetes causes buildup of keto acids; strenuous exercise causes lactic acid buildup; and renal failure). Renal compensation involves production of new bicarbonate ions. Metabolic alkalosis caused by a decrease in acids in the plasma from sources other than carbon dioxide (vomiting results in loss of stomach acid; or ingestion of alkaline drugs such as antacids). Renal compensation involves the kidneys excreting more bicarbonate ions and fewer hydrogen ions. (12 points each) Answer five of the following questions. Each can be answered in 4-8 wellworded sentences. 1. Describe the events of expiration during quiet breathing. 2. List and describe the three "lines of defense" to protect against pH changes in arterial blood and how quickly they act. 3. Describe the location and stimuli for central chemoreceptors and peripheral chemoreceptors involved in the control of breathing. 4. List and describe the four basic digestive processes. 5. Describe the countercurrent multiplier system of the kidney. 6. Describe the hormonal control of water balance. 7. List and describe three physiological changes that occur during space flight.
1. Describe the events of expiration during quiet breathing. Be sure to discuss the changes in various pressures. Quiet expiration is a passive process and does not require muscle contraction. The muscles in the chest wall relax causing the elastic chest wall and lungs to recoil to their resting position. As the chest wall and lungs recoil to their resting position, the volume of the lungs decreases, causing alveolar pressure to increase to greater than atmospheric pressure. Thus, air flows out of the lungs due to the pressure gradient until the volume in the lungs equals the functional residual capacity. 2. List and describe the three "lines of defense" to protect against pH changes in arterial blood and how quickly they act. a. Buffering of hydrogen ions acts immediately; important buffers (bicarbonate, proteins, and phosphates) to release or bind hydrogen ions to regulate pH.
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b. Respiratory compensation Usually acts within minutes; regulates arterial pH by increasing or decreasing alveolar ventilation, thus regulating bicarbonate and hydrogen ions. c. Renal compensation Takes hours to days to act; kidneys regulate arterial pH by regulating the renal excretion of hydrogen and bicarbonate ions and by producing new bicarbonate.
3. Describe the location and stimuli for central chemoreceptors and peripheral chemoreceptors involved in the control of breathing. . Central chemoreceptors Located in the medulla of the brain. They respond to changes in hydrogen ion concentration in the cerebrospinal fluid. Peripheral chemoreceptors Located in the carotid bodies near the carotid sinus. They respond to changes in arterial PO2, PCO2, and pH. 4. List and describe the four basic digestive processes. a. Digestion mechanical and chemical breakdown of food into smaller molecules. b. Absorption transport of small digestive end-products into the bloodstream. c. Secretion transport of fluids containing enzymes and other substances into the lumen of the GI tract. d. Motility GI contents are mixed and slowly propelled from one end of the tract to the other by contractile muscular activity. 5. Describe the countercurrent multiplier system of the kidney. The countercurrent multiplier system establishes the osmotic gradient in the renal medulla. The descending limb of the loop of Henle is permeable to water, so water diffuses out of the tubule under the influence of the osmotic gradient. The thick ascending limb is impermeable to water and has sodium, potassium, and chloride cotransporters. The term countercurrent refers to the fact that fluid flowing through the descending and ascending limbs moves in opposite directions. 6. Describe the hormonal control of water balance. Changes in the osmolarity of extracellular fluid are the strongest stimuli for antidiuretic hormone (ADH) release. If the osmolarity increases, the ADH secretion is stimulated and increases water reabsorption, thus decreases water excretion. Conversely, if the osmolarity of extracellular fluid decreases, ADH secretion is inhibited, which decreases water reabsorption and increases water excretion? 7. List and describe three physiological changes that occur during space flight. a. Cardiovascular system increasing in blood volume (fluid shift causing edema) b. Bone loss calcium and phosphorus are excessively excreted in urine and feces c. Muscles rapidly atrophy do to lack of use d. Space motion sickness rearrangement of the relationship of signals among signals from the vestibular system
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e. Hematologic effect RBCs decrease up to 15%; some RBCs transform into "mulberry" (round) shapes f. Immunologic effect Lymphocyte activity decreases
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