Quiz 1
1. The neurotransmitter associated specifically with skeletal muscle depolarization is ___.
C. Acetylcholine
2. Input to the soma is achieved via the _____, while output from the soma is achieved via the ______.
a. Dendrite; axon
3. A cluster of multiple somas in the PNS refers to a _____ (often found on an afferent nerve on the dorsal portion of the spinal cord).
C. Ganglion
4. When the nerve is at rest, the intracellular space (inside the membrane) is ____ charged relative to the extracellular space (outside the membrane).
a. Negatively
5. If more IPSPs are propagated to the soma of a postsynaptic cell compared to the EPSPs - what would be mostly likely be the end result at the axon hillock of the postsynaptic cell?
a. Hyperpolarization
6. The motor units associated with the muscles that control eye movements, which allow for more specific movements, are comprised of ________ muscle fibers corresponding to a single motor neuron than those motor units of the quadriceps..
b. Less
7. Which type of muscle fiber is activated initially during smooth coordinated muscle contraction?
a. Type I
8. True / False: Oligodendrocytes insulate axons of motor neurons that directly innervate muscle tissue.
False
9. Action potentials moving toward the spinal cord on the afferent nerve are considered _______, while action potential moving toward the spinal cord on an efferent nerve are _______.
B. Orthodromic; antidromic
10. The Na+/K+ pump mechanism works against the concentration gradient to pump ______ Na+ _______ the nerve cell1``` and _______ K+ _______ the cell.
d. 3; out of; 2; into
11. ____ synapses allow messages to occur almost instantaneously, while ____ synapses may have a > 5 ms delay.
b. Electrical; chemical
12. As the action potential is propagated in one direction down the nerve cell the inside of the nerve cell becomes more _____ as the polarity of the cell moves closer to reaching threshold.
a. Positively changed
13. Which structure of the soma starts the propagation of an action potential that will eventually act upon an effector organ?
c. Axon hillock
14. True / False: The vast majority of neurons within the nervous system are interneurons.
True
15. True / False: The depolarization of an inhibitory interneuron will cause an EPSP on the next neuron.
False