BIO 210 Chapters 9 and 11 – Study Questions
1. What type of molecule is a voltage-gated channel and where is it located? What does the term
voltage-gated mean? Provide a specific example of a voltage-gated channel.
2. What does the term resting membrane potential mean? How is the resting membrane potential established?
3. In terms of the generation of an action potential, what is the significance of the threshold voltage ?
4. The generation of an action potential is an All-or-None phenomenon. Explain what this means (why is it
an all or none event).
5. Draw a typical trace of the action potential as it occurs in a section of axonal membrane and label the
sections of the trace (include the status of ion channels, and the terms hyperpolarization, depolarization,
repolarization, threshold voltage, and resting membrane potential).
6. Define the term electrochemical gradient. Explain how electrochemical gradients are produced by muscle
and nerve cells.
7. Define and explain the differences between the absolute refractory period and relative refractory period.
8. Skeletal muscle anatomy is described by several terms that refer to its various organization levels as well as
other terms that refer to the CT sheaths surrounding the muscle. List these terms in the correct order from
small to large and provide a basic description for each term. (Your answer should include the terms:
muscle fiber, muscle, myofibril, actin, myosin, sarcomere, myofilament, fascicle, perimysium, epimysium,
endomysium)
9. Compare and contrast the phenomena referred to as graded potentials and action potentials. (You may use a
chart for this answer)
10. Define the terms EPSP (excitatory postsynaptic potential) and IPSP (inhibitory postsynaptic potential. What
is the significance of each in terms of the generation of an action potential?
11. Distinguish between continuous and saltatory conduction of nerve impulses. Explain why saltatory
conduction is faster.
12. Define and distinguish between temporal summation and spatial summation.
13. Following depolarization, Na+ channels close and voltage-gated K+ channels open. K+ diffuses out of the
cell, restoring the electrical polarity (but not the ionic conditions) of the resting state sarcolemma. Explain,
in your own words, what it means to restore the electrical polarity, but not the ionic conditions.
14. Describe the apparent structural changes that occur during partial and full muscle contraction in terms of
any alterations or lack of alterations seen in the A band, I band, H zone, M line, Z line, and the length of the
sarcomere.
15. ATP is the only energy source that is used directly for contractile activity. When available ATP is
hydrolyzed (4-6 seconds), it may be regenerated by three pathways. Describe these chemical pathways.
16. Vigorous exercise can cause dramatic changes in muscle chemistry as oxygen is consumed. What term
refers to the extra amount of O2 needed for a muscle to return to its pre-exercise state? Name at least four
restorative processes that are involved in returning the muscle to its pre-exercise state.
17. Fully explain the phenomenon known as rigor mortis.
18. Fully explain the ionic mechanisms of the depolarization, repolarization, and hyperpolarization events that
occur during the Action Potential. (What is happening during each of the events and why is it happening?)
19. Define the terms “Excitation-Contraction Coupling” and “Latent Period” Fully describe the events that
occur during the latent period.
20. Describe the events that occur when a nerve impulse reaches the neuromuscular junction. (Your answer
should include the following terms: motor end plate, ACh, neurotransmitter, vesicles, synaptic cleft, ACh
receptors, axon terminal, sodium channel, graded potential, action potential, calcium, voltage-gated calcium
channel)