1
Q
- Which of the following best describes homeostasis
a. Organisms maintain a constant, static internal environment
b. Most organisms have identical internal environments
c. Organisms do not change in response to an environmental change
d. Organisms maintain a narrow range of internal conditions
A
d. Organisms maintain a narrow range of internal conditions
2
Q
- Which of the following best illustrates homeostasis?
a. Most adult humans are between 5 and 6 feet tall
b. All the cells of the body are about the same size
c. When the salt concentration of the blood goes up, the kidneys expel more salt
d. When oxygen in the blood decreases, you feel dizzy
A
c. When the salt concentration of the blood goes up, the kidneys expel more salt
3
Q
- The process that produces the most ATP molecules per molecule of glucose is
a. Substrate-level phosphorylation
b. Oxidative phosphorylation
c. Anaerobic glycolysis
d. Negative feedback
A
b. Oxidative phosphorylation
4
Q
- Which of the following descriptions of movement of molecules across the plasma membrane is correct?
a. If 2 similar molecules can both combine with the same carrier, the presence of one of these molecules decreases the rate of entry of the other
b. In simple diffusion, the rate of transport of a molecule into the cell is directly proportional to the molecule’s extracellular concentration
c. When a carrier becomes saturated, the maximum rate of transport across the membrane is reached
d. Two of the above are correct
e. All of the above are correct
A
e. All of the above are correct
5
Q
- Which of the following is (are) NOT part of the peripheral nervous system?
a. Motor neurons
b. Sympathetic nervous system
c. Spinal cord
d. Afferent division
e. Autonomic nervous system
A
c. Spinal cord
6
Q
- Graded potentials
a. Are local changes in membrane potentials that occur in varying degrees of magnitude
b. Are local changes in membrane potential that occur only when threshold potential has been exceeded
c. Can be depolarizations or hyperpolarizations
d. Answers a and c are correct
e. Answers b and c are correct
A
d. Answers a and c are correct
7
Q
- Resting vm= -50mV
For K+: EK= -60mV
For Na+: ENa= +60mV
For which ion, Na or K, is the resting membrane potential further away from equilibrium?
a. Na+
b. K+
c. No difference
A
a. Na+
8
Q
- Next, you experiment with higher concentrations of BTX and find cases when the cell began to repolarize, it immediately depolarized again. This tells you that the toxin:
a. Prevents voltage-gated K channels from opening
b. Increases the speed that Na ion channels open
c. Prevents Na ion channels from closing
d. Makes Na ion channels close too soon
e. Doesn’t affect the Na ion channels at all, it affects the sodium-potassium pump instead
A
c. Prevents Na ion channels from closing
9
Q
- Poison dart frogs produce toxins (BTX) that act on voltage-gated Na channels in neurons and muscle cells. What is the effect on their predators?
a. Paralysis (no signaling)
b. Seizures (too much signaling)
c. Color change
d. Croaking
A
b. Seizures (too much signaling)
10
Q
What mechanism prevents these frogs from killing themselves?
a. They have no excitable cells
b. They have special colored skin
c. They have Na channels insensitive to BTX
d. They substituted K channels for Na channels
A
c. They have Na channels insensitive to BTX
11
Q
- Why can we not use X-rays for vision?
a. X-rays contain too little energy to affect rhodopsin
b. X-rays contain too much energy to affect rhodopsin
c. Our eyes block x-rays
d. The on and off center fields will flip-flop
A
b. X-rays contain too much energy to affect rhodopsin
12
Q
- A drug blocks nicotinic receptors. Administration of this drug will
a. Block parasympathetic activity on the heart
b. Block sympathetic activity on the heart block the release od epinephrine from the adrenal gland
c. A and b are both true
d. A, b, and c are all true
A
d. A, b, and c are all true
13
Q
- A sample of blood is withdrawn from the vessels or heart chambers listen below. Which sample best represents a mixture of venous blood from all systemic organs?
a. Vena cava
b. Right atrium
c. Left atrium
d. Pulmonary artery
e. Pulmonary vein
A
d. Pulmonary artery
14
Q
Which of the following could contribute to an increase in heart rate during exercise
a. Stimulation of sympathetic nerves to the heart
b. Inhibition of parasympathetic nerves to the heart
c. Release of catecholamines from the adrenal medulla gland
d. Only a and b are true
e. A, b, and c are all true
A
e. A, b, and c are all true
15
Q
- As a hospitalist is treating a patient with a pulmonary embolism, would the situation be most urgent if the clot was present in the pulmonary artery or the pulmonary vein?
a. The presence of a clot in the pulmonary artery would be more serious
b. The presence of a clot in the pulmonary vein would be more serious
c. The presence of a clot in the pulmonary artery or the pulmonary vein would be equally as serious
A
b. The presence of a clot in the pulmonary vein would be more serious
16
Q
- Administration of heparin to a patient with a deep vein thrombus will
a. Dissolve the blood clot
b. Prevent the blood clot from enlarging
c. Have little or no effect on the pre-existing blood clot
A
b. Prevent the blood clot from enlarging
17
Q
Resting heart rate (~70 beats per minute) is typically less than the inherent rhythm of the SA node (`80 to 100 events per minute). Which of the following could explain this phenomenon?
a. Sympathetic nerves stimulate the SA node under resting conditions
b. The vagus nerve stimulates the heart under resting conditions
c. Under resting conditions some impulses originating in the SA node are unable to move through the AV node
d. Beta receptors are stimulated by circulating epinephrine
A
b. The vagus nerve stimulates the heart under resting conditions
18
Q
- Production of protein hormones uses a multi-step process. Why not a single-step process? What is the most likely reason?
a. A multi-step process is faster
b. A multi step process allows an increased redundancy in case of a possible defect in pathway
c. A multi step process allows more control of the amount of end product (including amplification)
d. A multi-step process can be reversed if needed
e. Answers b and c
A
e. Answers b and c
19
Q
- Which other physiological process (es) use(s) a multi-step process allowing more control of the end product (response)?
a. Action potential production in neurons
b. Muscle contraction
c. ATP production from energy rich compounds
d. Answers b and c
e. Answers a, b, and c
A
d. Answers b and c
20
Q
- The specific action of hormones is due to
a. Hormone specific c-ATP
b. Variable affinity (high vs low)
c. Hormone-specific receptors in target cells
d. Hormone-specific adenylate cyclase in target cells
e. Binding of hormones to specific plasma proteins
A
c. Hormone-specific receptors in target cells
21
Q
- Which of the following statements concerning hormones is incorrect?
a. A single endocrine gland may produce multiple hormones
b. A single target cell may be influenced by more than one hormone
c. A single hormone can influence only one type of target cell (e.g. only a liver cell)
d. An endocrine organ may exert non-endocrine functions in addition to secreting hormones
e. Protein hormones are stored within the endocrine cell after being synthesized
A
c. A single hormone can influence only one type of target cell (e.g. only a liver cell)
22
Q
- The absence of PTH may result into the following:
a. Activation of vitamin D to produce greater Ca++ absorption in intestines
b. An increased reabsorption of Ca++ in kidneys
c. Bones take up Calcium and increase mineralization
d. Muscle cells pump Ca++ out of cell
e. All of the above
A
c. Bones take up Calcium and increase mineralization
23
Q
- Which of these is a neurosecretory organ rather than a true endocrine gland?
a. Anterior pituitary
b. Thyroid gland
c. Adrenal cortex
d. Posterior pituitary
e. Parathyroid gland
A
d. Posterior pituitary
24
Q
- Which of these sets of hormones is regulated by a very similar mechanism to the regulation of T3 and T4?
a. GnRH, growth hormone
b. PTH and calcium
c. CRH, ACTH, cortisol
d. None of the above
A
c. CRH, ACTH, cortisol
25
36. Which of these pituitary hormones is not released in response to a releasing hormone from the hypothalamus?
a. ACTH
b. ADH
c. FSH
d. Growth hormone
e. TSH
b. ADH
26
37. What does insulin do?
a. It adds GLUT-2 transporters to cell membranes
b. It phosphorylates intracellular glucose to facilitate glucose uptake by liver cells
c. It adds GLUT-4 transporters to fat and muscle cell membranes
d. It converts liver fatty acids to ketone bodies and promotes secretion of them into blood
e. Answers b and c
e. Answers b and c
27
38. What is the function of GLUT-2 transporters in cell membranes?
a. They facilitate glucose transport in all cells
b. They facilitate glucose transport in liver cells
c. They “sense” blood glucose levels and stimulate insulin release from pancreatic beta cells
d. They facilitate glucose transport in fat and muscle cells after insulin stimulation
e. Answers b and c
e. Answers b and c
28
39. Which of these is true of growth hormones?
a. Has a synergistic effect with insulin
b. Acts mainly on adipose tissue
c. Triggers processes that tend to increase blood glucose concentration
d. Triggers processes that tend to reduce fatty acids mobilization
e. Secreted by the hypothalamus
c. Triggers processes that tend to increase blood glucose concentration
29
Which of these is a consequence of our air (breathing) passage crossing our food passages?
a. Most of digestive tract uses peristalsis for transport
b. Esophageal phase of swallowing is rather slow
c. Chewing must occur after oral phase of swallowing
d. Pharyngeal phase of swallowing is very rapid
e. None of the above
d. Pharyngeal phase of swallowing is very rapid
30
41. Damage to the Cajal cells in the gastrointestinal wall will most likely result in
a. a non-functioning lower esophageal sphincter (LES)
b. a non-functioning receptive relaxation of the stomach
c. Absence of phasic contractions by smooth muscles
d. None od the above
c. Absence of phasic contractions by smooth muscles
31
42. Suppose you were working for a pharmaceutical firm and were assigned to search for drugs that might reduce stomach acid secretion. Which of the following would be the most promising?
a. A secretin antagonist
b. A cholecystokinin antagonist
c. A histamine agonist
d. A gastrin antagonist
e. Answers a and d
d. A gastrin antagonist
32
43. The intestinal phase of gastric secretion
a. Will decrease gastric secretion when gastrin is released by the duodenum
b. Leads to increased gastric secretion if duodenal pH falls below 2
c. Only stimulates gastric secretion
d. Is controlled by the entrance of acidic chime into the duodenum
e. Stimulates gastric motility when secretin is released by the duodenum
d. Is controlled by the entrance of acidic chime into the duodenum
33
44. Which pancreatic enzyme needs an activator?
a. Lipase
b. Amylase
c. Activase
d. ribonuclease
e. Trypsin
e. Trypsin
34
The effect of cholecystokinin (CCK) is to:
a. cause an increase in blood calcium concentration
b. Cause bile and pancreatic secretions to be added to small intestine (duodenum)
c. Inhibit release of pancreatic enzymes
d. Stimulate secretion of stomach acid and pepsin
e. Answers b and c
b. Cause bile and pancreatic secretions to be added to small intestine (duodenum)
35
46. The brush border of the epithelial cells in the lumen of the small intestine shows the importance of which physiological process
a. Diffusion
36
47. Which of these doe not play a role in lipid digestion and absorption
a. Cell surface receptors or transporters on villi cells
b. Emulsification by bile salts
c. Being split into fatty acids and monoglycerides
d. Transported from intestines by lacteals
e. Micelle formation
a. Cell surface receptors or transporters on villi cells
37
48. The kidney has significant absorption mechanisms for important ions such as calcium and sodium, but none for iron. The lack of an iron absorption mechanism is most likely due to
a. Iron ions can diffuse across membranes, and hence are passively reabsorbed
b. Iron ions cannot pass the glomerular basement membrane because of its charge
c. Other than that bound to hemoglobin, there is no iron in the blood
d. Iron in the plasma is not filtered because it is bound to proteins
d. Iron in the plasma is not filtered because it is bound to proteins
38
49. What is the function of the Juxtaglomerular apparatus?
a. It controls secretion of iron
b. It controls glomerular filtration rate
c. It controls the pore size of loop of henle
d. It controls glycogen reabsorption
b. It controls glomerular filtration rate
39
50. Constriction of afferent arterioles in the kidneys result in
a. A decrease in glomerular blood flow
b. An increase in glomerular capillary hydrostatic pressure
c. An increase in glomerular filtration rate
d. Answers a and b
e. Answers b and c
a. A decrease in glomerular blood flow
40
51. When the collection duct is permeable to water, the water is reabsorbed by osmosis into:
a. Glomerulus
b. Loop of Henle
c. Peritubular capillaries
d. Proximal convoluted tubule
e. Bowman’s capsule
c. Peritubular capillaries
41
52. As a result of countercurrent exchange, the fluid in the tubule is most hyperosmotic
a. In the proximal convoluted tubule
b. In the distal convoluted tubule
c. In the loop of Henle at the outer medulla
d. In the loop of Henle at the inner medulla
d. In the loop of Henle at the inner medulla
42
53. Which of the following plasma constituents is not regulated by hormones in the kidneys?
a. Water
b. Na+
c. Plasma protein
d. Glucose
e. Answers c and d
e. Answers c and d
43
54. Na+ reabsorption
a. Requires energy
b. Is under control of aldosterone in distal portions of the nephron
c. Is linked to reabsorption of glucose, amino acids and chlorine through secondary active transport or co-transport
d. Both answers a and b are correct
e. All of the above are correct
e. All of the above are correct
44
55. Solvent drag or bulk transport in the nephron includes transport of
a. urea
b. chlorine ions
c. fat-soluble substances
d. potassium
e. all of the above are correct
e. all of the above are correct
45
Which type of glial cells from the blood-brain barrier in the brain?
a. Astrocytes
b. Schwann Cells
c. Oligodendrocytes
d. Ependymal Cells
e. Microglia
a. Astrocytes
46
57. Place human blood cell in hypotonic solution would cause them to….
a. Swell first, then shrink
47
58. Which glial cells lines ventricles of the brain?
a. Ependymal cells
BIOL 646 Exam A
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