Human Anatomy and Physiology II
Exam 1, Version 8 - Feb. 16, 2001
Dr. Chabot
Multiple Choice (@3 points): Circle the letter of the one best answer. GOOD LUCK!
Answer only 27 out of 29! The first 27 answered will be graded.
1. In the central nervous system, masses of cell bodies appear
A. white
B. gray
C. brown
D. transparent
2. Relative refractory refers to
A. an all or none action potential
B. the time after an action potential during which a neuron is less sensitive to stimulus
C. your cousins who work in an automobile assembly plant
D. the fact that neurons are rapidly repolarized
3. The effects that a neurotransmitter will have on the post-synaptic membrane is determined primarily by:
A. the chemical structure of the transmitter
B. the type of pre-synaptic cell
C. the types of enzymes located in the synapse
D. the structure of the post-synaptic receptor
4. Neurotransmitters may be produced and packaged in the ________ of neurons.
A. axon
B. synapse
C. mitochondria
D. cell body
5. Astrocytes function to
A. nourish neurons in the central nervous system
B. increase the conduction velocity of action potentials
C. insulate axons in the CNS
D. insulate axons in the peripheral nervous system
6. When an action potential passes over the surface of a pre-synaptic membrane, the contents of vesicles are released in response to the influx of
A. calcium ions
B. sodium ions
C. neurotransmitters
D. neuropeptides
7. During an action potential
A. a small percentage of the total number of Na ions diffuse into the cell
B. a small percentage of the total number of K ions diffuse out of the cell
C. a large percentage of the total number of Na ions diffuse into the cell
D. a large percentage of the total number of K ions diffuse out of the cell
E. A and B only
F. C and D only
8. The application of tetraethyl ammonium ion (TEA) to a neuron (axon) will
A. prevent the production of action potentials
B. remove the Na inactivation gate and cause a long term depolarization after stimulation
C. prevent hyperpolarization of the neuron after an action potential
D. all of the above
9. The selectivity of the K and Na ion channels can be explained solely on the basis of
A. the number of these channels in the membrane
B. the size of the pore (hole) of the channel
C. the water attracting or stripping properties of the inside of the channel
D. B and C only
E. all of the above
10. The units used to measure the resting potential of a nerve fiber are
A. watts
B. millivolts
C. millimeters
D. calories
11. After an action potential, the nerve cell membrane re-develops a resting potential and
A. potassium channels in the membrane open and potassium ions diffuse outward
B. a wave of action potentials travels the length of the nerve fiber as a nerve impulse
C. sodium channels in the membrane open and sodium ions diffuse inward
D. ion channels close and the membrane becomes less permeable to sodium and potassium
12. The process of transmitting a nerve impulse from one neuron to another involves a
A. nerve impulse stimulating pre-synaptic dendrites to release a neurotransmitter into a synaptic cleft
B. nerve impulse stimulating pre-synaptic axons to release a neurotransmitter into a synaptic cleft
C. neurotransmitter traveling from pre-synaptic dendrites across a synapse to post-synaptic axons or a cell body
D. neurotransmitter traveling from post-synaptic axons across a synapse to pre-synaptic dendrites or a cell body
13. A nerve cell membrane may become depolarized as a result of
A. unequal distribution of ions on each side of the membrane
B. some ion channels being opened while others are closed
C. the relative ease with which potassium ions diffuse through membranes
D. totally preventing sodium ions from passing through the membrane
14. In the synapse, a receptor can be
A. a protein
B. a channel
C. a recognition site for a neurotransmitter
D. B and C only
E. All of the above
15. Inhibitory post synaptic potentials (IPSPs) involve
A. the opening of Na channels
B. the opening of K channels
C. a depolarization of the membrane
D. A and C only
E. None of the above
16. Chemical synaptic transmission differs from electrical synaptic transmission in that
A. only one involves channels
B. only one involves the depolarization of the membrane
C. only one requires that neurotransmitters be synthesized in the neuron
D. only one involves the transmission of "information" from one cell to another
E. none of the above
17. Neurotransmitters may affect the post-synaptic cell by
A. causing a depolarization of the membrane
B. causing modification of ion channels via a second messenger
C. causing a change in the metabolism of the cell via a second messenger
D. causing a change in protein synthesis via a second messenger
E. all of the above
18. If the body had a low calcium level, then this could affect the release of neurotransmitters by
A. increasing the quantity released from synaptic knobs
B. breaking down acetylcholine to acetyl and choline in synaptic knobs
C. causing a decrease in the amount released from synaptic knobs
D. causing a greater amount to be synthesized and stored in synaptic knobs
19. In a neuron, the long-term maintenance of a resting potential involves
A. Na channels
B. Na/K pumps
C. the lipid bilayer
D. B and C only
E. All of the above
20. The most rapid nerve impulses are conducted on fibers that are
A. thick and myelinated
B. thick and unmyelinated
C. thin and myelinated
D. thin and unmyelinated
21. When a neurotransmitter binds to a receptor in the post-synaptic membrane, this causes
A. an action potential
B. a "graded" potential
C. an EPSP or an IPSP
D. B and C only
E. all of the above
22. When an inhibitory neurotransmitter combines with a receptor site on a post-synaptic membrane an:
A. influx (inward flow) of potassium ions occurs.
B. influx of sodium ions occurs.
C. efflux of sodium ions occurs.
D. efflux (outward flow) of potassium ions occurs.
23. Which of the following is (are) a type of neuroglial cell?
A. an astrocyte
B. an oligodendrocyte
C. a Schwann cell
D. A and B only
E. all of these
24. Neurons are different than other cells because they lack:
A. endoplasmic reticulum
B. a nucleus
C. golgi apparatus
D. mitochondria
E. None of the above
25. A series of post-synaptic potentials (PSPs) sum to produce a membrane potential of -40 mV at the axon hillock. Assume the threshold of this neuron is -45 mV. Which of the following will occur?
A. No action potential will be generated.
B. The action potential generated will be proportional to the strength of the PSPs.
C. The action potential generated will be inversely proportional to the strength of the PSPs.
D. An action potential will be generated.
26. Hyperpolarization of the neuronal membrane may be produced by any factor that:
A. increases the membrane's permeability to sodium ions.
B. decreases the membrane's permeability to sodium ions.
C. stimulates the sodium-potassium pump.
D. increases the membrane's permeability to potassium ions.
27. Two neurons X and Y have excitatory input onto neuron Z. The terminal of neuron X is located 0.64 µm from the axon hillock of neuron Z, while the terminal of neuron Y is located 0.07 µm from the hillock. If, at different times, both X and Y stimulate neuron Z at the same rate and cause the same amount of post-synaptic depolarization at the terminals:
A. Neuron X will have a lesser chance of causing neuron Z to fire
B. Neuron Y will have a lesser chance of causing neuron Z to fire
C. They will both cause neuron Z to fire since action potentials are all-or-none
D. They both have an equal chance to cause neuron Z to fire.
28. At the neuromuscular junction which of the following is true?
A. Norepinephrine is released and is removed from the synapse by diffusion.
B. Norepinephrine is released and is removed from the synapse via reuptake.
C. Acetylcholine is released and is removed from the synapse via enzymatic breakdown.
D. Acetylcholine is released and is removed from the synapse via reuptake.
29. Which of the following pertains to an article(s) that I mentioned in class?
A. Increased TV viewing is linked to violence in children
B. A mis-packaged herbal supplement caused kidney failure in hundreds of people in Europe.
C. Creatine phosphate supplements have now been linked to cancer.
D. All of the above.
Essay/Short Answer (@ 10 pts). Answer only 2 of the following 3. The first 2 answered will be graded.
1) Draw and label a diagram showing a cross section through the spinal cord. Be as detailed as you can.
2) Describe how an action potential occurs in an axon. You may use diagrams to support your written text.
4) Describe the process of summation that occurs in post-synaptic membranes. You may use diagrams to support your written text.