What substance is secreted by electrical synapses between neurons in the brain?
a. ATP
b. ACTH
c. GnRH
d. GRH
e. glucose
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Question 2) Which statement(s) is/are true about membrane potentials?
a. They are differences in electrical charge on opposite sides of a membrane
b. They are measured in millivolts, with the sign designating the charge on the outside
c. They exist because the ECF as a whole is positively-charged and the cytosol as a whole is negatively charged
d. They are always positive during the resting state
e. All of the above statements are true.
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Question 3) What are the two types of synapses between neurons?
a. physical and chemical
b. primary and secondary
c. active and passive
d. electrical and chemical
e. open and closed
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Question 4) Anionic intracellular proteins (A-) cannot pass through membrane carriers because A- proteins
a. are charged
b. they can only pass through channels
c. are in about the same concentration in the cytosol and ECF
d. too large
e. are synthesized outside the cell, and carriers only transport them into the cell
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Question 5) On what three structures can a neuron terminate?
a. spinal cord, peripheral nerve, or organ
b. smooth muscle, striated muscle, or cardiac muscle
c. gland, other neuron, or blood vessel
d. peripheral nerve, spinal nerve, or brain neuron
e. muscle, gland, or other neuron
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Question 6) A Ca2+ pump in the plasma membrane
a. pumps Ca+2 into the cell
b. is a secondary active transport carrier
c. is an ATPase
d. is a symporter
e. allows Ca+2 to diffuse into the cell
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Question 7) In addition to myelination, what else influences the speed with which an axon can conduct action potentials?
a. number of dendrites
b. fiber diameter
c. fiber length
d. size of the cell body
e. proximity of the nerve to spinal cord
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Question 8) Glucose enters some cells
a. through primary active transport
b. through secondary active transport
c. through facilitated diffusion
d. all of the above processes
e. through A and C only
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Question 9) The strength of a stimulus is coded by the ____.
a. strength of action potentials
b. frequency of action potentials
c. duration of the resting period
d. duration of the refractory periods
e. frequency of salutatory periods
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Question 10) The rate of carrier-mediated transport is limited by
a. the glycocalyx
b. osmolarity
c. tonicity
d. competition with other molecules
e. the number of protein channels present in the membrane
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