BIOL 3420 – Animal Physiology (prof. A. Hontela)
Study questions – October 2011
1. Negative and positive feedbacks mediate numerous physiological responses. Choose the correct
answer (one only)
a) Negative and positive feedback both depend on signal inversion and amplification
b) Negative feedback depends on signal amplification but positive feedback does not
c) Negative and positive feedback both depend on signal inversion
d) None of the above
2. Passive transport of solutes across cell membranes
a) moves molecules of solute from a lower concentration to a higher concentration
b)
c)
d)
e)
f)
moves molecules of solute from a higher concentration to a lower concentration
always requires ATP expenditure
does not require ATP expenditure
moves water from a concentrated compartment to a diluted compartment
facilitates movement of hydrophilic substances
1. a, c, e
2. b, c, e
3. a, c, f
4. b, d, e
5. b, d, f
3. Acetylcholine is the neurotransmitter released at
a) the postganglionic terminals of the sympathetic and parasympathetic nervous system
b) motor endplates and the postganglionic terminals of the parasympathetic nervous system
c) the preganglionic and postganglionic terminals of the sympathetic nervous system
4. During a relative refractory period
a) no stimulus applied to the axon will elicit an AP
b) a supranormal stimulus applied to the axon will generate a supranormal AP
c) a normal stimulus applied to the axon will generate a subnormal AP
d) a supranormal stimulus applied to the axon will generate a subnormal AP
5. Oxidative muscle fibers have
a. many mitochondria, few capillaries and lots of myoglobin
b. few mitochondria, few capillaries and low levels of myoglobin
c. many mitochondria, many capillaries, and lots of myoglobin
d. few mitochondria, many capillaries and low myoglobin
6. An excitatory transmitter released at a chemical synapse
a) generates a hyperpolarizing current and depolarize the postsynaptic membrane
b) generates a depolarizing current and increases conductance to K+
c) generates a hyperpolarizing current and increases conductance to Na+
d) generates a depolarizing current and increases conductance to Na+
e) none of the above
7. A pharmacological agent acting as a post-synaptic antagonist of Ach at the neuromuscular junction
a) will block the release of Ach from pre-synaptic vesicles
b) will block the action of AchE in the synaptic cleft
c) will cause flaccid paralysis of muscles
d) will mimic the action of Ach and generate rigid paralysis
e) none of the above
8. What are the similarities and the differences between an endocrine cell and a neurosecretory cell?
9. List two (2) characteristics of the axon hillock area of a neuron.
10. Compare voltage-gated channels and ligand-gated channels.
11. Blood progesterone levels in women are low during the luteal phase of the menstrual cycle and
high during the follicular phase.
True or False
12. What is the T tubule in a striated myofibril and what is its role in muscle contraction?
13. Cell membranes are typically inside negative. What is the contribution of the Na+/K+ pump to this
condition?
14.
i) Define the equilibrium potential for an ion.
ii) Calculate ENa+ at
[Na+]o = 9mM and
[Na+]i = 120mM.
iii) Given Vm = -92mV, calculate the electromotive force for Na+ in this preparation.
A. Explain the contraction-relaxation cycle in a skeletal muscle. How would this process be influenced
by a hormonal disorder causing abnormally low levels of calcium in the blood?
B. Compare graded potentials and all-or-none impulses.
C. Males of many amphibian species undergo a rapid testicular development as daylength increases in the
spring. The males also develop special breeding colors and start to call females to attract them to a
territory for mating. Explain the links between the nervous and endocrine systems that mediate this
process