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Name:
EXAM III
Animal Physiology
ZOO 428
Winter 2012
Total: 300 Points
 B  NSB 
  100
% Bound  
B

NSB
 0

TH2O = GFR – UF
TX = (GFR)(PX) – (UF)(UX)
U 
C X  UF   X 
 PX 
 GFR – UF 
%TH2O  
  100
 GFR 
 (GFR)(PX ) – (UF)(UX ) 
  100
%TX  
(GFR)(PX )


1. (80 points) Ingestion of a carbohydrate-rich meal causes an acute rise in the plasma glucose
concentration. This increase in plasma glucose concentration initiates a series of cellular and
molecular events that ultimately brings the plasma glucose concentration back to the resting
level. Please provide detailed responses to the following, and please be sure to use diagrams:
a. (10 points) Prepare a plot of the plasma glucose concentration after a carbohydrate-rich meal.
Your plot should report average values for plasma glucose concentration immediately before and
up to five hours after ingestion of the glucose-rich meal. Assume a normal physiological
response (i.e., the response is not pathological).
b. (20 points) Describe the cellular and molecular processes that are responsible for the rise in
plasma glucose concentration after a carbohydrate-rich meal is ingested.
c. (25 points) Fully describe the molecular events that are induced by the rise in plasma glucose
concentration. Your response should focus on the endocrine pancreas.
d. (25 points) Fully describe the molecular events that bring the plasma glucose concentration
back to the resting level. Your response should focus on pancreatic hormone action in target
tissues.
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2. (60 points) In humans, the urine osmolality can range from 50 mOsm/L during well-hydrated
conditions (diuresis), to about 1200 mOsm/L under dehydrated conditions (antidiuresis). Explain
in detail the mechanisms responsible for the ability of the kidney to produce urine that is either
hypo-osmotic or hyper-osmotic to plasma. Please be sure to use diagrams.
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3. (60 points) Explain in detail the role of the renin-angiotensin-aldosterone system in Na+, K+,
and fluid balance in the body. Be sure to discuss both systemic and molecular events. Please be
sure to use diagrams.
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4–13. (2 points each) For questions 4 through 13, complete each row in the table by entering
the appropriate information in the blank cell. Be sure to be as specific as possible.
Cells, Tissue, or
Gland Responsible
Target Cell,
Question Hormone Name
Hormone Action
for Synthesis and
Tissue, or Organ
Release
Synthesis and
release of
Hypothalamus
Anterior pituitary
4
adrenocorticotropic
hormone
5
Anterior pituitary
Myoepithelial cells
in breast
Milk production
6
Hypothalamus /
posterior pituitary
Myoepithelial cells
in breast
Milk ejection
7
Pancreatic alpha
cells
Primarily liver
Increase plasma
glucose
concentration
Many tissues
Development of
secondary sexual
characteristics
8
Androgens
9
Insulin
Pancreatic beta
cells
10
Thyrotropin
releasing
hormone
Hypothalamus
Anterior pituitary
Hypothalamus /
Posterior pituitary
Collecting duct of
kidney nephrons
11
Decrease plasma
glucose
concentration
12
Parathyroid
hormone
Parathyroid Glands
Kidney, Bone,
Intestine
13
Growth hormone
releasing
hormone
Hypothalamus
Anterior pituitary
Water reabsorption
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Questions Requiring VERY Short Answers
14. (2 points) In most target tissues, the physiologically active form of the thyroid hormone is:
15.
(2 points) In humans, this hormone is the most important hormone product of the zona
fasciculata of the adrenal cortex.
16. (2 points) The parafollicular cells of the thyroid gland secrete this hormone.
(2 points) Binding of Ca2+ to this regulatory protein is important in smooth muscle
excitation-contraction coupling.
17.
18.
(2 points) In the endocrine pancreas, clusters of endocrine cells are responsible for the
synthesis and production of various hormones. What are these cell clusters called?
19. (2 points) Approximately how many nephrons are present in each human kidney?
20. (2 points) The pores within the slit diaphragms of the glomerular filtration barriers have
these dimensions: __________ nm × __________ nm.
21. (2 points) This amount of water (in liters) is reabsorbed every day in the proximal tubules of
both kidneys combined.
22. (2 points) What is the glomerular filtration rate (GFR) in an average-sized adult individual?
Your response should be a number and its associated unit(s).
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23. (2 points) In the presence of the antidiuretic hormone, the water that is reabsorbed from the
lumen of the collecting duct is returned to the circulation via these capillaries:
24. (2 points) Molecules reabsorbed from the lumen of the proximal tubule are returned to the
circulation via the these capillaries:
25.
(2 points) In the thyroid gland, this enzyme is responsible for organification of iodide,
which involves incorporation of elemental iodine into the thyroglobulin molecule (i.e., iodination
of thyroglobulin).
26. (2 points) This cytoplasmic enzyme converts T4 to T3.
27. (2 points) This enzyme is responsible for iodination of thyroglobulin.
28. (2 points) Macula densa cells of the distal tubule release this paracrine factor that plays a
role in tubuloglomerular feedback.
29. (2 points) Hydrostatic blood pressure in the glomerular capillaries is approximately:
30. (2 points) Plasma membrane invaginations of the basal domain are referred to as:
31. (2 points) These epithelial junctions are responsible for regulating the permeability of the
paracellular pathway.
32. (2 points) These epithelial junctions are responsible for intercellular communication.
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33. (2 points) These epithelial junctions are responsible for cell attachment to the basal lamina.
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Multiple-Choice Questions
34. (2 points)
The function of the gastrointestinal tract can be summarized by the following
mechanism(s): (A) Motility; (B) Secretion; (C) Digestion; (D) Absorption; (E) All of the
above.
35. (2 points) Which one of the following is consistent with absorption of glucose molecules
across the intestinal epithelium? (A) Glucose enters the intestinal epithelial cell through glucose
channels in the apical membrane and leaves the cell through the basal membrane by facilitated
diffusion; (B) Glucose enters through the apical membrane by facilitated diffusion and leaves
through the basal membrane by facilitated diffusion also; (C) Glucose enters the cell through the
apical membrane by co-transport with Na+ and leaves the cell through the basal membrane by
facilitated diffusion; (D) Glucose enters the cell through the apical membrane by facilitated
diffusion and leaves the cell through the basal membrane by co-transport with Na+; (E) None of
the above.
36. (2 points) Most of the chemical digestion in the GI tract occurs in the:
(A) Mouth; (B)
Stomach; (C) Small intestine; (D) Large intestine.
37. (2 points) Most of the water and electrolytes absorbed across the walls of the GI tract is
absorbed in this region: (A) Stomach; (B) Small intestine; (C) Large intestine.
38. (2 points) Fat digestion begins in this region of the gastrointestinal tract:
(A) Mouth; (B)
Stomach; (C) Duodenum of the small intestine; (D) Jejunum of the small intestine; (E) Large
intestine.
39. (2 points) Protein digestion begins in this region of the gastrointestinal tract:
(A) Mouth;
(B) Stomach; (C) Duodenum of the small intestine; (D) Jejunum of the small intestine; (E)
Large intestine.
40. (2 points)
Carbohydrate digestion begins in this region of the gastrointestinal tract: (A)
Mouth; (B) Stomach; (C) Duodenum of the small intestine; (D) Jejunum of the small intestine;
(E) Large intestine.
41.
(2 points) Nucleic acid digestion begins in this region of the gastrointestinal tract: (A)
Mouth; (B) Stomach; (C) Duodenum of the small intestine; (D) Jejunum of the small intestine;
(E) Large intestine.
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42. (2 points) Before fat molecules are eventually placed into micelles in the lumen of the GI
tract, they are digested by pancreatic lipase to form: (A) Free fatty acids; (B) Glycerol; (C)
Monoglycerides; (D) A and B; (E) A and C.
43. (2 points) The chemical digestion of this class of compounds begins in the small intestine.
(A) Proteins; (B) Lipids; (C) Nucleic acids; (D) A, B, and C; (E) B and C only.
44.
(2 points) Which of the following is true about the enteric nervous system? (A) It is
capable of responding independently to stimuli within the gastrointestinal tract; (B) Its function
is regulated by the autonomic nervous system; (C) It is sometimes referred to as the “little
brain”; (D) It uses serotonin as its main neurotransmitter; (E) All of the above.
45. (2 points) In the stomach, HCl is secreted by:
(A) HCl cells; (B) Neurons of the enteric
nervous system; (C) Parietal cells; (D) Goblet Cells; (E) Chief cells.
46. (2 points) All of the following are secreted by the pancreas into the duodenal region of the
small intestine EXCEPT: (A) Bicarbonate; (B) Amylase; (C) Nuclease; (D) Peptidase; (E)
Intrinsic factor.
47. (2 points) The interstitial cells of Cajal are responsible for:
(A) Regulating the osmolality
of the kidney interstitial fluid; (B) Secreting secretin into the interstitial fluid of the small
intestine; (C) Setting the contractile rhythm of the smooth muscle of the segments of the GI
tract; (D) Secreting cholecystokinin into the bloodstream; (E) Secreting the antidiuretic
hormone into the bloodstream.
48. (2 points) Parietal cells
are responsible for secreting: (A) HCl; (B) Pepsinogen; (C)
Intrinsic factor; (D) A and C; (E) A, B, and C.
49. (2 points) The main action of gastrin is to:
(A) Stimulate HCl secretion into the stomach;
(B) Stimulate pancreatic bicarbonate secretion; (C) Stimulate pancreatic enzyme secretion; (D)
Stimulate secretion of insulin.
50. (2 points) The main action of secretin is to:
(A) Stimulate HCl secretion into the stomach;
(B) Stimulate pancreatic bicarbonate secretion; (C) Stimulate pancreatic enzyme secretion; (D)
Stimulate secretion of insulin.
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51. (2 points) The main action of Cholecystokinin (CCK) is to:
(A) Stimulate HCl secretion
into the stomach; (B) Stimulate pancreatic bicarbonate secretion; (C) Stimulate pancreatic
enzyme secretion; (D) Stimulate secretion of insulin.
52. (2 points) The main action of gastric inhibitory peptide (GIP) is to:
(A) Stimulate HCl
secretion into the stomach; (B) Stimulate pancreatic bicarbonate secretion; (C) Stimulate
pancreatic enzyme secretion; (D) Stimulate secretion of insulin.
53. (2 points) pH of the gastric fluid is about:
(A) 1.5; (B) 3.5; (C) 5.5; (D) 7.5; (E) 9.5.