Download Final Exam - Creighton Biology

Name: __________________________
Biology 449 - Animal Physiology
Spring 2008
Final Exam
Fill in your scantron form as follows:


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.
In the field of physiology, when we say that the kidneys help regulate sodium levels, we are
referring to sodium levels in the
a.
b.
c.
d.
e.
blood.
cytosol.
interstitial fluid.
Two of the above.
All of the above.
If an animal is trying to regulate K+ levels in its body, and K+ levels are too high, which of the
following patterns would likely bring the most rapid return to desired levels?
f.
g.
h.
i.
j.
Increased K+ influx, increased K+ efflux
Increased K+ influx, decreased K+ efflux
Decreased K+ influx, increased K+ efflux
Decreased K+ influx, decreased K+ efflux
Hunker down and hope for the best.
In human thermoregulation, the activity of sweat glands in controlled by the sympathetic nervous
system. In the context of the negative feedback loop controlling body temperature, which
component do neurons in the sympathetic system represent?
k.
l.
m.
n.
o.
Sensors
Afferent pathways
Integrating centers
Efferent pathways
Effectors
Which of the following must normally be present for the generation of a membrane potential to
occur?
p.
q.
r.
s.
t.
At least one charged particle.
Permeability of the membrane to at least one charged particle.
Permeability of the membrane to two or more charged particles.
a and b.
a and c.
1
Consider a mammal having a mutation that caused the myelin covering of its neurons to develop
without nodes of Ranvier (i.e., there is a contiguous myelin covering along the entire
neuron). What would be the likely effect on the propagation of action potentials in a
relatively long neuron?
u. Propagation would be faster due to better insulation along the entire axon.
v. Propagation would be faster due to less time taken up generating new action
potentials at the nodes.
w. Propagation would be slower due to less ion exchange between the cell and interstitial
fluid.
x. Propagation would be slower due to reduced regeneration of membrane potential by
new action potentials.
y. Propagation of action potentials along the entire neuron would not occur.
The release of synaptic vesicles from the cytoskeleton of a presynaptic neuron is directly
triggered by (i.e., the thing that actually causes the release is)
z. an influx of Ca2+ ions into the neuron.
aa. an efflux of Ca2+ ions from the neuron.
bb. an influx of Cl- into the neuron.
cc. an influx of Na+ ions into the neuron.
dd. an efflux of K+ ions from the neuron.
The term “excitatory post synaptic potential” refers to
ee. A single, relatively short lived depolarization of a postsynaptic neuron is response to
a single action potential arriving at a presynaptic neuron.
ff. A single, relatively short lived hyperpolarization of a postsynaptic neuron is response
to a single action potential arriving at a presynaptic neuron.
gg. The sum of all depolarizing effects acting on a postsynaptic neuron from all
presynaptic neurons combined.
hh. The sum of all hyperpolarizing effects acting on a postsynaptic neuron from all
presynaptic neurons combined.
ii. The condition in which the postsynaptic neuron is depolarized to threshold, initiating
an action potential.
In the sensory system, a receptor that senses mild pressure applied to the skin’s surface is an
example of a
jj. chemoreceptor.
kk. mechanoreceptor.
ll. nociceptor.
mm. photoreceptor.
nn. thermoreceptor.
2
In most tonic-type sensory neurons, an increase in stimulus intensity is encoded as
oo. an increase in the amplitude of each action potential.
pp. an increase in the duration of each action potential.
qq. an increase in action potential frequency.
rr. Two of the above.
ss. All of the above.
Which of the following is not known to activate any class of taste receptors?
tt. Amino acids
uu. Fats
vv. Hydrogen ions
ww. Salt
xx. Sugars
A person who lacked functioning hair cells would have trouble
yy. with her equilibrium.
zz. hearing.
aaa. feeling pain.
bbb. Two of the above.
ccc. All of the above.
If one sound strongly vibrated the region of the basilar membrane near the cochlea’s base, and
another sound strongly vibrated the region near the cochlea’s tip, that means the sounds
differ in their
ddd. duration.
eee. frequency.
fff. volume.
ggg. What’s that, sonny? Bass guitar hen’s brain?
hhh. I said “BASILAR MEMBRANE.”
The drug l-cis-diltiazem blocks cGMP-gated Na+ channels such as those found in vertebrate
photoreceptors, so that Na+ cannot enter the cell. What would be the expected effect of this
drug on photoreceptor function?
iii. It would keep the cells depolarized, as if they were always in the dark.
jjj. It would keep the cells depolarized, as if they were always in the light.
kkk. It would keep the cells hyperpolarized, as if they were always in the dark.
lll. It would keep the cells hyperpolarized, as if they were always in the light.
mmm. It would make for a groovy light show, man.
3
Given their source (i.e., gonads), testosterone and estrogen must be an example of
nnn. amines.
ooo. neurohormones.
ppp. peptide hormones.
qqq. prostaglandins.
rrr. steroid hormones.
Which of the following is not believed to be a tropic hormone?
sss. Adrenocorticotropic hormone
ttt. Gonadotropin releasing hormone
uuu. Luteinizing hormone
vvv. Prolactin releasing hormone
www. All of the above are tropic hormones.
In adults, long bones no longer increase in length because
xxx. growth hormones levels are too low to promote growth at the epiphyseal plates.
yyy. sex hormone levels are too low to promote growth at the epiphyseal plates.
zzz. increased sex hormone levels have caused the epiphyseal plates to “close,” or
become inactive.
aaaa. no activity of osteoblasts occurs after puberty.
bbbb. Long bones do increase in length throughout life.
If a sarcomere is lengthened beyond its normal resting length, its ability to produce force will be
decreased because
cccc.
dddd.
eeee.
ffff.
gggg.
there is less overlap between the myosin heads and thin filaments.
tropomyosin can no longer easily move away from myosin binding sites on actin.
thin filaments begin overlapping, causing interference.
elastic forces tend to pull the Z-lines back together.
the effective concentration of ATP is reduced.
As a whole muscle is called on to produce more and more force, the last motor units recruited
will consist of
hhhh. relatively small numbers of slow oxidative fibers.
iiii. relatively large numbers of slow oxidative fibers.
jjjj. relatively small numbers of fast glycolytic fibers.
kkkk. relatively large numbers of fast glycolytic fibers.
llll. Motor units within a muscle do not differ in their composition.
4
Force
Force
Which of the following graphs shows the normal pattern of force production during an isometric
twitch contraction?
Time
Time
Force
b.
Force
mmmm.
Time
d.
Force
c.
Time
Time
e.
If 10.0 liters/min is flowing through the left heart, which of the following will also have
10 liters/min flowing through it?
nnnn.
oooo.
pppp.
qqqq.
rrrr.
The systemic arteries
The systemic capillaries
The system veins
The right heart
All of the above will have 10 liters/min flowing through them.
If heart rate increases but cardiac output remains the same, then
ssss. stroke volume must have decreased.
tttt. stroke volume must have increased.
uuuu. total peripheral resistance must have decreased.
vvvv. total peripheral resistance must have increased.
wwww. Heart rate does not affect cardiac output.
5
If there is increased vasoconstriction within a particular organ, the effect will be (assuming no
other changes occur)
xxxx. decreased blood flow to that organ and decreased total peripheral resistance.
yyyy. decreased blood flow to that organ and increased total peripheral resistance.
zzzz. increased blood flow to that organ and decreased total peripheral resistance.
aaaaa. increased blood flow to that organ and increased total peripheral resistance.
bbbbb. Instant organ death
The rate at which lymph is formed (about 4 liters/day) is a result of
ccccc. osmotic pressure forcing blood out of the capillaries, countered by hydrostatic
pressure inward that is about 10% as strong.
ddddd. osmotic pressure forcing blood out of the capillaries, countered by hydrostatic
pressure inward that is about 90% as strong.
eeeee. hydrostatic pressure forcing blood out of the capillaries, countered by osmotic
pressure inward that is about 10% as strong.
fffff. hydrostatic pressure forcing blood out of the capillaries, countered by osmotic
pressure inward that is about 90% as strong.
ggggg. combined hydrostatic and osmotic pressure forcing blood out of the capillaries.
During the inhalation phase of the resting ventilatory cycle, the intrapleural pressure
hhhhh. starts positive and increases further during inhalation.
iiiii. starts positive but decreases during inhalation.
jjjjj. starts at zero but decreases during inhalation.
kkkkk. starts negative and decreases further during inhalation.
lllll. starts negative but increases during inhalation.
For a person with an anatomical dead space of 140ml, a tidal volume of 440ml, and a ventilation
frequency of 10 breaths/min, the alveolar ventilation rate would be
mmmmm. 1400 ml/min
nnnnn. 3000 ml/min
ooooo. 4400 ml/min
ppppp. 5800 ml/min
qqqqq. incalculable from the information given.
Most carbon dioxide that enters the blood is transported in the form of
rrrrr. dissolved CO2.
sssss. carbamino compounds.
ttttt. bicarbonate ion.
uuuuu. Carbon dioxide is present in about equal amounts in two of these forms.
vvvvv. Carbon dioxide is present in about equal amounts in all three of these forms.
6
The oxygen affinity curve shown below is for myoglobin. Based on this curve, about how much
oxygen will be offloaded from myoglobin if the PO2 of surrounding muscle drops from 40
torr to 10 torr?
Oxygen Saturation Curve
120
%MbO2
100
80
60
40
20
0
0
10
20
30
40
50
PO2
wwwww. 20%
xxxxx. 40%
yyyyy. 50%
zzzzz. 60%
aaaaaa. 80%
When discussing gastrointestinal physiology, the term “absorption” refers to
bbbbbb. the breakdown of food into simpler components.
cccccc. the transport of food across the epithelial layer of the gut.
dddddd. the uptake of nutrients by the liver.
eeeeee. the transport of nutrients by the blood and lymph.
ffffff. the storage of nutrients for future use.
Bile salts are important in the digestion of fats because
gggggg. they promote the release of digestive enzymes by the pancreas.
hhhhhh. they break fats down into fatty acids and glycerol.
iiiiii. they act as detergents to help emulsify fat droplets.
jjjjjj. they transport fatty acids across the apical membrane of the epithelial cells.
kkkkkk. they transport fats across the basolateral membrane of the epithelial cells.
During the post-absorptive phase, fat cells normally
llllll. take up fatty acids and store them as fat.
mmmmmm. take up glucose and convert them to fat for storage.
nnnnnn. release fatty acids for use by the nervous system.
oooooo. release fatty acids for use by most cell types.
pppppp. a and b
7
Normally, an increase in levels of the hormone leptin
qqqqqq. decreases metabolic rate.
rrrrrr. results from an increase in fat stores.
ssssss. results from a sudden decrease in food intake.
tttttt. results from sudden weight loss.
uuuuuu. results in an increase in appetite.
If a substance S enters the nephrons at a rate of 1.0mg/min, and exits the nephrons at a rate of
1.0mg/min, which of the following is likely true? (Be sure to read carefully!)
vvvvvv. S is being reabsorbed by the kidneys.
wwwwww. S is being secreted by the kidneys.
xxxxxx. S is neither being reabsorbed nor secreted by the kidneys.
yyyyyy. It is impossible to guess how the kidneys are handling S.
zzzzzz. There really aren’t any other choices, are there?
Most of the reabsorption of water (by volume) in the nephrons takes place in the
aaaaaaa.
bbbbbbb.
ccccccc.
ddddddd.
eeeeeee.
proximal tubule.
descending loop of Henle.
ascending loop of Henle.
distal tubule.
collecting duct.
2. Antidiuretic hormone has its main effects by
a.
b.
c.
d.
e.
altering sodium reabsorption in the distal tubule and collecting duct.
increasing permeability of the collecting ducts to water.
upregulating activity by the loop of Henle.
decreasing the rate of formation of the primary urine.
promoting vasodilation.
3. Which of the following would trigger antidiuretic hormone release most strongly?
a.
b.
c.
d.
e.
Decreased blood osmolarity and decreased blood pressure
Decreased blood osmolarity and increased blood pressure
Increased blood osmolarity and decreased blood pressure
Increased blood osmolarity and increased blood pressure
ADH is not affected by blood osmolarity.
The region of the juxtaglomerular apparatus that senses sodium levels in the urine is the
f.
g.
h.
i.
j.
afferent arteriole.
efferent arteriole.
granular cells.
macula densa.
sympathetic osmoreceptors.
8
In males, the release of testosterone
k.
l.
m.
n.
o.
is from the Leydig cells and is promoted by follicle stimulating hormone.
is from the Leydig cells and is promoted by luteinizing hormone.
is from the Sertoli cells and is promoted by follicle stimulating hormone.
is from the Sertoli cells and is promoted by luteinizing hormone.
Who needs testosterone when you have anabolic steroids?
In men, the erection of the penis results from
p.
q.
r.
s.
t.
vasodilation of arterioles and vasocompression of venules.
vasoconstriction of arterioles and vasocompression of venules.
vasodilation of arterioles and vasoexpansion of venules.
vasoconstriction of arterioles and vasoexpansion of venules.
So many possibilities here that could get me in trouble…
In women,
u. estrogen is made de novo by the theca cells.
v. estrogen is made de novo by the granulosa cells.
w. androgen is made by the theca cells and converted into estrogen by the granulosa
cells.
x. androgen is made by the granulosa cells and converted into estrogen by the theca
cells.
y. estrogen is made outside the ovaries.
The effects of progesterone on the uterus include
z. the promotion of endometrial growth.
aa. the promotion of nutritive secretions by the endometrium.
bb. the inhibition of contractions by the uterus.
cc. Two of the above.
dd. All of the above.
Short answer (beginning on next page):
Write a concise answer to each question. 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.
9
4. Provide a brief (one or two sentence) description and an example for each of the following
routes of transport across a cell membrane:
Primary active transport:
Secondary active transport:
Permeation:
Facilitated diffusion:
5. For each of the following, briefly (one or two sentences) indicate the effects of the change in
channel state on membrane voltage during an action potential:
Opening of voltage-gated K+ channels:
Opening of voltage-gated Na+ channels:
Closing of voltage-gated K+ channels:
Closing of voltage-gated Na+ channels:
10
6. Using a reasonably detailed diagram or a written description, describe the hormonal pathway
associated with the thyroid gland, including effects of the thyroid hormone(s) and any
feedback loops.
7. Describe the by which a single action potential arriving at a muscle fiber causes the muscle to
first initiate and then end contraction. Discuss only events that occur outside the myofibril,
not the molecular events involving the thick and thin filaments.
11
8. Put the following cardiac cycle events in the correct sequence by providing ordered list of the
identifying letters:
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
Atrioventricular valves open
Atrioventricular valves close
Semilunar valves open
Semilunar valves close
Isovolemic ventricular contraction
Isovolemic ventricular relaxation
Atrial contraction
Ventricular ejection
Blood begins moving from atria into ventricles
Sinoatrial node action potential triggered
Ventilation rate
Ventilation rate
9. In the figures below, draw in the approximate relationship between ventilation rate and a) PO2
and b) PCO2 levels. The dotted lines represent normal resting ventilation rates, and the units
for ventilation are arbitrary – I am not looking for exact ventilation rates, so none need to be
added. Briefly (a few sentences) explain the reason for the different pattern in the two
figures.
0
20
40
60
80
100
120
36
Arterial PO2 (torr)
40
44
Arterial PCO2 (torr)
12
48
Choose two of the following three hormones associated with digestion and diagram or describe
the associated pathways and negative feedback loops: Gastrin, cholecystokinin, and secretin.
10. Diagram or describe the pathways and feedback loop associated with the renin-angiotensinaldosterone system. Be sure the action(s) of each component is/are clear.
13
11. Describe the events that occur in creating a mature sperm from a spermatogonium. You
should indicate where different events take place, but you do not need to describe the
hormonal pathways that support spermatogenesis.
Blood Hormone Level
12. On the graph below, draw in lines representing the approximate levels of progesterone,
estrogen and luteinizing hormone across the “normal” 28 menstrual cycle of a woman. Also
indicate (in whatever way is most convenient) the time at which each of the events below
occurs.
0
7
14
Time (days)
a.
b.
c.
d.
e.
Ovulation
Beginning of follicular development
Appearance of the dominant follicle
Menstruation
Luteal phase
14
21
28