Student ID _______________________
Animal Physiology 2009
Exam II
Name ____________________________________
Part I
Part II
Part III
Part IV
Part V
Part VI
Part VII
___________ (10)
___________ (17)
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___________ (15)
___________ (16)
___________ (15)
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Total
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Please read each question carefully. Make sure you completely answer each question. In some sections, 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 properly labeled graphs, diagrams, illustrations to support your
conclusions.
No electronic devices, books or notes may be accessed during this exam.
This exam has 8 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
typed explanation along with the original test to Dr. Mensinger within one week of your exam being returned. You
should detail why you feel your answer deserves more credit.
1
Student ID _______________________
I) Very short answer ( 1 pt each)
What do the following acronyms/abbreviations stand for
Example Ach - Acetylcholine
1) EOD
2) JAR
3) ITD
4) SIZ
5) EPSP
6) AP
7) ENa
8) IK
9) gNa
10) Vm
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Student ID _______________________
Section II)
1) What type of eye is illustrated at the right (2 pts)
2) The figure below shows the typical response pattern of a particular sensory cell
What type of sensory cell is it? (1 pt)
What type of stimuli does it encode? ( 1 pt)
Explain how the receptor cell works to produce the asymmetrical curve shown. (3 pt)
3) What is the function of the round window ( 2 pts )
4) Follow the path of a sound particle from the environment to the CNS by arranging the pertinent terms in the correct
order ( 3 pts )
A) External Auditory canal
B) Oval window
C) Hair cell
D) Inner ear bones (malleus, incus and stapes)
E) Auditory (cochlear) nerve
F) Tympanic membrane
H) Semicircular canal
Put the letters in the correct order in the box
5) What is the first retinal layer that light encounters when it travels into the eye. ( 2 pts)
6) Trace the path of a photon retinal capture to the highest order cell we described in the CNS. The photon was
captured in the fovea. (3 pts )
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Student ID _______________________
III: Sketch the membrane potential for each cell in the table boxes to show its reaction to a brief light
stimulus. The white portion of the two circles indicates where the light is shining. The photoreceptor is
contained within the smaller, inside circle and synapses directly to the on- bipolar cell. The on bipolar cell
synapses directly to the on-ganglion cell. For these questions you do not have to worry about labeling the
axes or drawing a scale bar. You just need to show how the membrane potential will change during a brief
light stimulus (2 pts each square)
I
II
Photoreceptor
(in inner circle)
On bi polar cell
On ganglion cell
4
Student ID _______________________
IV) The resting potential of a cell is -60 mv. The temperature is 15oC. Draw a membrane potential in response to
Membrane potential (mV)
depolarizing threshold stimulus that was initiated at 2 ms in the diagram below. ENa is 60 mV. The refractive period is
5 ms.
100
80
60
40
20
0
-20
-40
-60
-80
-100
0
2
4
6
8
10
TIME (ms)
Membrane potential (mV)
B) Draw the corresponding gNa and gK to the scenario outlined in Part A
100
80
60
40
20
0
-20
-40
-60
-80
-100
0
2
4
6
8
10
TIME (ms)
Membrane potential (mV)
C) Draw the corresponding membrane if a toxin the blocks K+ channels is added prior to the threshold stimulus in the
scenario outlined in part A
100
80
60
40
20
0
-20
-40
-60
-80
-100
0
2
4
6
8
10
TIME (ms)
5
Student ID _______________________
V) An axon has a resting potential of -80 mv and a threshold potential of -50 mv. There are 5 locations on
the axon labeled A through E, each separated by 1 mm. Position A is closest to the soma. You have a
recording electrode at A, B, D, E and a stimulating electrode at position C. Sites B and D are covered by
myelin. You have a recording electrode in position C. Part I) Show the membrane voltage at all four
recording positions when the stimulating electrode depolarizes the cell by 15 mv. Part II) Show the
membrane voltage at all four recording positions when the stimulating electrode depolarizes the cell by 45
mv. The temperature is 15 oC. Do not worry about scale bars or labels. However do pay attention to the
relative change in membrane potential when necessary.
Site
Part I
Part II
A
B
C
D
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Student ID _______________________
VI. True or False (Do 3 of 4) 5 pts each. Indicate whether the following statements are true or false. If the statement
is true, provide a figure/graph that supports the claim. If the statement is false, correct the entire statement.
1) The figure below was used to illustrate parallel stimulation in the house cat by Hubel and Weisel.
2) Frequency varies linearly with the size of the receptor potential but cannot exceed the limit set by the refractory
period.
3) In the toad vision experiment, as the square stimulus increased uniformly in size there was a bimodal behavioral
response to the stimulus
4) August Krogh, Bob Barlow and Eric Haldane won the The Nobel Prize in Physiology or Medicine 1963 "for their
discoveries concerning the ionic mechanisms involved in excitation and inhibition in the peripheral and central
portions of the nerve cell membrane"
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Student ID _______________________
VII) True or False II (Do 3 of 4) 5 pts each. Indicate whether the following statements are true or false. If the
statement is true, provide a figure/graph that supports the claim. If the statement is false, correct the entire statement
1) The axon in the giant squid, Architeuthis, was the foundation for early neurobiology studies. It was chosen
because because as a typical large diameter axon, axon potentials traveled down its axon very slowly.
2) In the frog neuromuscular junction, the neurotransmitter is TTX. It is broken down in the cleft palate by the
enzyme TEA into two components, TT and X that are reabsorbed by the post synaptic neuron.
3) Electrical synapses provide very fast transmission of current between two neurons however they are not good for
long distance transmission due to the rapid attenuation of the signal
4) Vertebrate photoreceptors do not release neurotransmitter in the dark because of the dark current. When stimulated
by photons, their membrane will depolarize. The stimulus from the photoreceptor is in the form of an action potential.
This stimulus travels from photoreceptors to horizontal cells to ganglion cells. At the ganglion cell level, the action
potential is converted to a graded potential that is sent directly to the visual cortex.
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Student ID _______________________
1) Stimulus modality is encoded by both the amplitude and the duration of the action potential
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