Download Final Exam - Creighton Biology

Name: __________________________
Biology 449 - Animal Physiology
Fall 2007
Final Exam
Fill in your scantron form as follows:
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Write and bubble in your name in the upper left (last name first).
Sign your form in the upper right. By so doing you verify that you are abiding
by Creighton’s policy on academic honesty.
Multiple choice: As always, choose the best answer for each multiple-choice question.
Answer on your scantron form. Each question is worth 3 points.
Claude Bernard realized that the significance of the “internal environment” to physiology was
that
a. the internal environment, also known as the cell cytosol, could be regulated by
individual cells.
b. the internal environment, also known as the extracellular fluid, could be regulated so
that cells had a favorable environment.
c. the internal environment, also known as the blood, would remain well mixed because
it was constantly moving.
d. the right internal environment, or microhabitat, could reduce the need for regulation.
e. the big money was in interior decorating.
Two isotonic solutions are placed in a system that separates them by a membrane of unknown
permeability. After some time has passed, the volume of one solution has increasd and the
other has decreased. Which of the following could be true?
f.
g.
h.
i.
j.
One or more of the solutes also crossed the membrane.
The hydrostatic pressure differed across the membrane.
The membrane is impermeable to water.
Two of above could be true.
All of the above could be true.
A typical system involving secondary active transport would include which of the following?
k.
l.
m.
n.
o.
A channel protein
A cotransporter
An ATP-powered carrier protein
Two of above
All of the above
In order to calculate the equilibrium membrane potential generated by the movement of a single
ion down its concentration gradient, the most appropriate equation would be the
p.
q.
r.
s.
t.
Fick equation.
Goldman equation.
Nernst equation.
Poisson equation.
Starling equation.
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Consider a neural synapse in which the formation of docking proteins has been blocked through
the action of siRNA. At what stage would normal synaptic transmission first be interrupted?
u.
v.
w.
x.
y.
Ca2+ would not enter the presynaptic terminal.
Synaptic vesicles would not be released from the presynaptic cytoskeleton.
Neurotransmitter would not be released into the synaptic cleft.
Neurotransmitter would not have an effect on the postsynaptic neuron.
Neurotransmitter would not be taken back up by the presynaptic neuron.
Which of the following statements about ionotropic vs. metabotropic receptors in postsynaptic
neurons is true?
z. Ionotropic receptors have greater effects on membrane potential because they allow
through only divalent ions (e.g. Ca2+).
aa. The effects of ionotropic receptors last longer because neurotransmitters bind to them
permentanly.
bb. Ionotropic receptors have only inhibitory effects on postsynaptic neurons.
cc. Metabotropic receptors have longer lasting effects because they are intracellular
receptors that control gene expression.
dd. Metabotropic receptors can have a stronger effect on membrane potential because
each receptor can serve to activate multiple ion channels.
Which of the following would have an inhibitory effect on a postsynaptic neuron?
ee. An increased influx of Cl-.
ff. An increased influx of Na+.
gg. An increased influx of Ca2+
hh. A decreased efflux of K+
ii. All of the above would have an inhibitory effect.
A phasic sensory receptor is one that
jj. doesn’t show a change in action potential frequency as long as stimulus intensity
stays constant.
kk. shows a strong increase in action potential frequency while stimulus intensity is
changing, but a low action potential frequency in response to a constant stimulus.
ll. has a large receptive field.
mm. has a small receptive field.
nn. inhibits adjacent afferent neurons.
In the conversion of sound into neural impulses in mammals, the step that actually activates the
mechanoreceptors involved occurs when
oo. the tympanic membrane moves relative to the auditory meatus.
pp. the auditory ossicles move relative to the oval window.
qq. the vestbular membrane moves relative to the basilar membrane.
rr. the tectorial membrane moves relative to the organ of Corti.
ss. the round window moves relative to the cochlea.
2
In photoreceptors, photons are detected by a system involving
tt. the cleaving of a retinal into two separate molecules.
uu. the fusion of two molecules into a retinal.
vv. a change in the conformation of retinal.
ww. the phosphorylation of retinal.
xx. the deamination of retinal.
Which of the following is not true of hormones?
yy. They can be released by glands.
zz. They can be released by modified neurons.
aaa. Their release can be triggered by other hormones.
bbb. Their release can be triggered by neural activity.
ccc. They reach only a small number of cells in the body.
Which of the following is an effect of increased cortisol levels?
ddd. Increased metabolic rate
eee. Increased growth rate
fff. Increased sexual development
ggg. Decreased immune function
hhh. Decreased blood pressure
Which of the following shows the correct cascade of hormone release in the hypothalamicpituitary-thyroid gland system?
iii. Thyroid stimulating hormone  thyrotropin releasing hormone  thyroxine
jjj. Thyroid stimulating hormone  thyroxine  thyrotropin releasing hormone
kkk. Thyrotropin releasing hormone  thyroxine  thyroid stimulating hormone
lll. Thyrotropin releasing hormone  thyroid stimulating hormone  thyroxine
mmm. Thyroxine  thyrotropin releasing hormone  thyroid stimulating hormone
The primary component of the thin filaments of muscles is
nnn. actin.
ooo. dynein.
ppp. keratin.
qqq. kinesin.
rrr. myosin.
As the load increases on a muscle during isotonic twitch contractions, which of the following
values will decrease?
sss. Shortening distance
ttt. Shortening velocity
uuu. Duration of muscle shortening
vvv. Two of the above will decrease.
www. All of the above will decrease.
3
During a normal heartbeat, the short delay between atrial and ventricular contraction is
introduced by the
xxx.
yyy.
zzz.
aaaa.
bbbb.
atrioventricular node.
bundle of His.
Purkinje fibers.
sinoatrial node.
ventriculoarterial node.
With regard to general cardiovascular function, the parasympathetic nervous system is primarily
responsible for altering
cccc.
dddd.
eeee.
ffff.
gggg.
heart rate.
stroke volume.
arteriole diameter throughout the body.
The peripheral nervous system has major effects on two of the above.
The peripheral nervous system has major effects on all of the above.
If the gastrointestinal system as a whole undergoes vasodilation, which of the following would
be true if no other changes occurred in the cardiovascular system?
hhhh. There would be decreased flow to the GI tract and an increase in total peripheral
resistance.
iiii. There would be decreased flow to the GI tract and a decrease in total peripheral
resistance.
jjjj. There would be increased flow to the GI tract and an increase in total peripheral
resistance.
kkkk. There would be increased flow to the GI tract and a decrease in total peripheral
resistance.
llll. There would be increased flow to the GI tract and no change in total peripheral
resistance.
Which of the following substances is exchanged between the blood and interstitial fluid
primarily through the pores between capillary endothelial cells?
mmmm. Carbon dioxide
nnnn. Oxygen
oooo. Proteins
pppp. Red blood cells
qqqq. Sodium ions
During which phase of the normal resting ventilatory cycle will intrapleural pressure be lowest?
rrrr. At the start of inhalation
ssss. At mid inhalation
tttt. At the end of inhalation
uuuu. At mid exhalation
vvvv. Intrapleural pressure does not change during the ventilatory cycle.
4
Based on the oxygen affinity curve shown below, about how much oxygen will be offloaded
from the hemoglobin if the blood moves from a region of PO2 = 60 to PO2 = 30?
%HbO2
100
80
60
40
20
0
0
20
40
60
80
100
120
140
PO2
wwww. 20%
xxxx. 30%
yyyy. 40%
zzzz. 60%
aaaaa. 90%
Which of the following will not result in a right shift of the oxygen affinity curve of
hemoglobin?
bbbbb. An increase in CO2 levels
ccccc. An increase in temperature
ddddd. An increase in 2,3-DPG
eeeee. An increase in pH
fffff. All of the above will result in a right shift of the oxygen affinity curve.
The reason mammals don’t typically show a strong ventilatory response to drops in arterial PO2
of up to 25 torr is that
ggggg. they can easily switch to anaerobic metabolism.
hhhhh. they have enough oxygen stored in myoglobin to last for an hour or more.
iiiii. there are no sensors for oxygen in the body.
jjjjj. hemoglobin is still nearly completely saturated even at a PO2 80 torr.
kkkkk. carbon dioxide levels tend to drop at the time as oxygen levels, counteracting the
ventilatory drive.
5
The release of the hormone gastrin by the stomach is not promoted by
lllll. stomach distension.
mmmmm. increased acidity in the stomach.
nnnnn. the parasympathetic nervous system.
ooooo. the presence of peptides in the stomach.
ppppp. All of the above promote the release of gastrin.
During the digestion and absorption of fats from the lumen of the small intestine, fatty acids
cross from the lumen into epithelial cells via
qqqqq. simple diffusion across the cell membrane.
rrrrr. permeation through channel proteins.
sssss. facilitated diffusion through carrier proteins.
ttttt. primary active transport through carrier proteins.
uuuuu. cotransport with Na+ through symport proteins.
Which of the following tissues generally relies on glucose as a source of energy in both the
absorptive and post-absorptive states?
vvvvv. Fat cells
wwwww. Muscle
xxxxx. Nervous tissue
yyyyy. General tissues
zzzzz. None of the above
Which of the following is true about the absorptive state?
aaaaaa. Glucose is found at high levels in the bloodstream due to the breakdown of fats.
bbbbbb. Little anabolic activity is taking place.
cccccc. Liver cells are converting glucose into glycogen.
dddddd. Insulin levels are low.
eeeeee. Amino acids are being stored as a primary source of energy for the postabsorptive period.
The production of urine at the glomerulus is driven by
ffffff. active transport.
gggggg. diffusion.
hhhhhh. hydrostatic pressure.
iiiiii. osmotic pressure.
jjjjjj. secretion.
6
A typical rate of reabsorption of water from the primary urine filtered into the nephron is
kkkkkk. 1%
llllll. 10%
mmmmmm. 30%
nnnnnn. 50%
oooooo. 99%
A disease called diabetes insipidus (unrelated to the disease commonly known simply as
diabetes, which is actually diabetes mellitus) can result from a lack of anti-diuretic hormone
receptors in the kidney. The expected effect of having this condition would be
pppppp. production of small amounts of very concentrated urine.
qqqqqq. production of small amounts of very dilute urine.
rrrrrr. production of large amounts of very concentrated urine.
ssssss. production of large amounts of very dilute urine.
tttttt. a lot of confusion over what you meant when you said “diabetes.”
The effects of aldosterone are to
uuuuuu. increase vasoconstriction.
vvvvvv. increase vasodilation.
wwwwww. increase reabsorption of sodium from the urine.
xxxxxx. increase secretion of sodium into the urine.
yyyyyy. promote the release of renin.
Which of the following would not be expected as part of the response to hypovolemic shock
resulting from blood loss?
zzzzzz. A higher heart rate than before the blood loss.
aaaaaaa. A higher stroke volume than before the blood loss.
bbbbbbb. More vasoconstriction than before the blood loss.
ccccccc. An increase in release of ADH and renin.
ddddddd. Wishing you were lying on a floor in a warehouse in Reservoir Dogs.
In order for Sertoli cells to promote spermatogenesis, they must be activated by sufficient levels
of
eeeeeee. follicle-stimulating hormone.
fffffff. luteinizing hormone.
ggggggg. testosterone.
hhhhhhh. Sertoli cells must be activated by two of the above.
iiiiiii. Sertoli cells must be activated by all of the above.
7
Spermatozoa are generally mature
jjjjjjj. when they initially form from spermatocytes.
kkkkkkk. within a few hours of forming.
lllllll. within a few days of forming.
mmmmmmm. within a few months of forming.
nnnnnnn. within a few years of forming.
The source of most of the volume of semen is the
ooooooo. bulbourethral glands.
ppppppp. ejaculatory duct.
qqqqqqq. prostate gland.
rrrrrrr. seminal vesicles.
sssssss.testes.
In both men and women, the primary effect of inhibin appears to be to
ttttttt. decrease the rate of release of follicle-stimulating hormone.
uuuuuuu. increase the rate of release of follicle-stimulating hormone.
vvvvvvv. decrease the rate of release of luteinizing hormone.
wwwwwww. increase the rate of release of luteinizing hormone.
xxxxxxx. keep you from having a good time.
Which of the following best describes the level of hormones in a woman one week after
ovulation?
yyyyyyy. Levels of estrogen and progesterone are relatively low; LH levels are
relatively high.
zzzzzzz. Levels of estrogen and progesterone are relatively high; LH levels are
relatively low.
aaaaaaaa. Levels of estrogen are relatively high; LH and progesterone levels are
relatively low.
bbbbbbbb. Levels of estrogen, progesterone and LH are all relatively low.
cccccccc. Levels of estrogen, progesterone and LH are all relatively high.
In which phase of the uterine cycle is successful implantation of a blastocyst possible?
dddddddd. The menstrual phase
eeeeeeee. The proliferative phase
ffffffff. The secretory phase
gggggggg. Implantation is possible in two of the above phases.
hhhhhhhh. Implantation is possible in two of the above phases.
In humans, implantation typically occurs about how long after fertilization?
iiiiiiii. One minute
jjjjjjjj. One hour
kkkkkkkk. One day
8
llllllll. One week
mmmmmmmm. One month
Which of the following best describes the pattern of estrogen production during pregnancy?
nnnnnnnn. Levels are fairly constant. Estrogen is first produced mainly by the mother,
then by the fetus.
oooooooo. Levels are fairly constant. Estrogen is first produced mainly by the fetus, then
by the mother.
pppppppp. Levels are increasing. Estrogen is first produced mainly by the mother, then
by the fetus.
qqqqqqqq. Levels are increasing. Estrogen is first produced mainly by the fetus, then by
the mother.
rrrrrrrr. Estrogen levels are low throughout pregnancy.
Short answer: Write a concise answer to each of the following questions. Your answers
should fit in the spaces provided. Diagrams may be used but must be
accompanied by sufficient explanation to make the components clear.
Each question is worth 8 points.
2. In lecture we discussed the effects of parathyroid hormone on Ca2+ regulation in the extracellular fluid. Another hormone involved in this process is calcitonin. C cells in the thyroid
gland (which are distinct from the cells that secrete thyroid hormone) detect blood Ca2+
levels and release more calcitonin as Ca2+ levels increase. Calcitonin affects bone osteoblast
activity (bone building) and the rate of excretion of Ca2+ by the kidneys.
Based on this information, diagram the likely negative feedback loop for calcitonin and its
effects. Also identify the following parts of the loop: combined sensor/setpoint/integrating
center(s), efferent pathway(s), effector(s), and regulated variable(s).
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3. On the following diagram of an action potential in a neuron, the dotted line indicates the
threshold voltage.
a. Indicate the approximate times at which a) VG Na+ channel activation gates are open, b) VG
Na+ channel activation gates are closed, c) VG Na+ channel inactivation gates are open, d)
VG Na+ channel inactivation gates are closed, e) VG K+ channels are open, and f) VG K+
channels are closed.
b. How might the action potential change if a drug that blocked the VG K+ channels was
applied to the neuron?
4. The otolith organs (the utricle and saccule) sense linear acceleration. Describe how these
organs work, including in your description a discussion of the sensory cells involved.
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5. Describe the process by which the process of cross-bridge cycling is controlled (i.e. turned on
and off) within the myofibrils. You do not need to explain the other aspects of excitationcontraction coupling, just what occurs within the myofibrils.
6. These questions refer to ventricular systole.
a. Describe the patterns of blood pressure, blood flow and valve activity that occur during
systole, and the relationships among these variables.
b. In mitral regurgitation, the valve between the left atrium and left ventricle starts leaking.
How might this change the patterns discussed above?
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7. These questions relate to ventilation.
a. If you are taking 20 breaths a minute of 650 ml each, and you have a typical anatomical dead
space, what will be your i) minute ventilation rate and ii) alveolar ventilation rate? Show
your work.
b. When I was a young lad I used to imagine I could sit at the bottom of the swimming pool,
breathing through a garden hose like it was a snorkel. Would this be likely to work? Why or
why not?
8. Diagram or describe the negative feedback loops involving the following hormones from the
small intestine:
a. Cholecystokinin
b. Secretin
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9. Describe the process of reabsorption of sodium, glucose, water and urea in the proximal
tubule. You do not need to discuss the details of the pathways taken by the solutes through
and between the epithelial cells.
10. Describe the process by which the human male achieves an erection.
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11. Within the ovary, what are the major events occurring during the complete menstrual cycle,
and what is the timing of these events? You do not need to discuss the hormone levels
associated with these events.
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