Animal Physiology 2004
Exam I
Name ____________________________________
Part I
Part II
Part III
Part IV
Part V
Part VI
___________ (20)
___________ (9)
___________ (24)
___________ (25)
___________ (12)
___________ (10)
Total
___________ (100)
Please read each question carefully. Make sure you completely answer each question. In each
section, you will be able to choose which questions you would like to answer. Please clearly
indicate which of these questions you have chosen. You are more than welcome to use graphs,
diagrams, illustrations to support your conclusions
This exam has nine pages including this title page.
Animal Physiology regrade policy: If you feel a mistake has been made in the grading of your
exam, please submit a written explanation to Dr. Mensinger within one week of your exam being
returned. You should detail why you feel your answer deserves more credit.
1
I) Short answer identification- Please choose 4 of the following 9 terms. Make sure you circle
the terms that you would like graded or we will do the first 4 that have writing. Identify or
define the following terms, names or animals and indicate their importance in physiology or
what concept they were used to illustrate. (5 pts each)
1) calsequestrin
2) T-tubules
3) tropomyosin
4) Sarcomere
5) Fast twitch oxidative muscle
6) Node of Ranvier
7) dihydropyridine receptor
8) spike initiation zone
9) myelin
Part II
The following scientists ( or pairs ) have all been mentioned in lecture. Please choose 3 of the
following 8 terms. Make sure you circle the names that you would like graded or we will do the
first 3 that have writing. Please indicate what discoveries were associated with them or what
was their contribution to science. (3 points each)
1) Hogdkin and Huxley
2) Stephen Kuffler
3) Bernard Katz
4) A.F. Huxley and R. Niedergerke
2
5) H.E. Huxley and J. Hanson
6) Heilbrun
7) Hill
8) A. Huxley and Taylor
Part III: Please answer 4 of the following 5 questions. Circle the number of the question you
would like graded. (6 points each)
1) What would be the advantage of a sensory neuron that has a spontaneous firing rate versus a
sensory neuron that is normally silent and just fires when it is sufficiently stimulated?
2) Seminar question:
What fish does Dr. Mensinger use as a model.
Name another fish that was mentioned in the seminar. Name a sensory system that Dr.
Mensinger works on.
3) What effect would relative filament length have on the length tension curve and why?
4) A frog nerve contains four classes of neurons. 3 of the classes are myelinated and have the
following diameters, 100, 50, and 10 microns. The fourth class is unmyelinated and is 10
microns in diameter. If you stimulate all four classes simultaneously and place a recording
electrode downstream from the stimulus site, indicate which fiber class would arrive first and
which would arrive last. Explain why.
5) Botulinum (the toxin responsible for Botulinism) is a toxin that can cause death by blocking
the release of Ach at the neuromuscular junction. However, it is now being used by plastic
surgeons to treat wrinkles. These are called BO-TOX injections. Explain why normally sane
(however vain) people would have their doctor inject poison under their skin ie explain how the
toxin injection could prevent wrinkles ( a diagram of the synapse would be helpful)
IV) Adaptation of muscle for diverse activities: We have discussed adaptation for power
(frogs), adaptation for contrasting function (fish swimming muscles) and adaptation for speed
(sonic muscle). Take one of these systems and discuss the properties of the muscle (or muscles)
that have made it ideally suited for the appropriate task. It would be useful to make references to
“normal muscle” or one of the other two systems to explain your answer. You are strongly urged
to make diagrams/figures to explain your answer. At a minimum you should graph the
appropriate force and power diagrams. PLEASE NOTE: The actual numbers are not as
important as the relative differences between the two muscle types. Please stop and think for a
few minutes before answering this question. A well structured answer will be worth more than a
regurgitation of the lecture notes. Please make sure to accurately label all diagrams (25 pts).
3
V: You are investigating the following circuit. Neuron A has a chemical synapse onto Neuron B and
Neuron B innervates a skeletal muscle.
You have the following 4 poisons to use. You can use three of the poisons. The flow chart traces the
circuit pathway from neuron A through muscle relaxation. Place the number of the poison next to arrow
where the circuit would be must effectively blocked by the addition of the poison (4 pts each).
Example: A ) Tetrodotoxin which is derived from the puffer fish binds to a site on voltage gated Na+ and
blocks Na+ across the membrane
1) Botulinum toxin blocks the release of ACh at the neuromuscular junction
2) Eserine blocks the action of acetylcholinesterase
3) CAX binds with free Ca++ in muscle cells and lowers the [ ] of free Ca++
4) CyanoX destroys an enzyme in muscle cells responsible for the production of ATP
Neuron A
Synapse
between A
and B
Mysosin x
bridge
attachment
to actin
change in
troponin
molecules
Sarcomere
shortening
Myosin
detachment
Neuron B
Ryanodine
receptor
channels
open
Tropomysin
prevents x
bridge
attachment
Neuromuscular
synapse
Dihydropyridine
receptor rchange
shape
Muscle
relaxation
VI) You are working on nerve that has a resting potential of -60 mv. If you depolarize the nerve
by 40 mv, you will get an action potential that will peak at +80 mv. The nerve has an absolute
refractory period of 2 ms (after the completion of the action potential) and an additional 4 ms
relative refractory period. Plot the membrane potential of the nerve between 0 and 10 ms. Note:
The action potential duration is of typical 2 ms duration. Draw the membrane potential for the
following scenarios. 10 pts total @ 2.5 pts each.
A) Applying a 2 ms hyperpolarizing stimulus of 40 mv at 2 ms
4
Membrane potential (mV)
100
80
60
40
20
0
-20
-40
-60
-80
-100
0
2
4
6
8
10
TIME (ms)
Membrane potential (mV)
B) Applying a 1 ms depolarizing stimulus of 50 mv at 2 ms
100
80
60
40
20
0
-20
-40
-60
-80
-100
0
2
4
6
8
10
TIME (ms)
Membrane potential (mV)
C) Applying a 1 ms depolarizing stimulus of 50 mv at 2 ms and again at 5 ms
100
80
60
40
20
0
-20
-40
-60
-80
-100
0
2
4
6
8
10
TIME (ms)
D) The poison X blocks voltage gated K+ channels. Draw the membrane potential of a 2 ms
depolarizing stimulus of 50 mv at 2 ms (following the addition of the poison)
5
Membrane potential (mV)
100
80
60
40
20
0
-20
-40
-60
-80
-100
0
2
4
6
TIME (ms)
6
8
10
7