Ch. 11 Fundamentals of the Nervous System and Nervous Tissue
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Problem 3
Assume that an EPSP is being generated on the dendritic membrane. Which will occur? a. specific Na⁺ channels will open, b. specific K⁺ channels will open, c. a single type of channel will open, permitting simultaneous flow of Na⁺ and K⁺ , d. Na⁺ channels will open first and then close as K⁺ channels open.Problem 8
The anatomical region of a multipolar neuron where the AP is initiated is the a. soma, b. dendrites, c. axon's initial segment, d. axon terminals.Problem 12
Since all APs generated by a given nerve fiber have the same magnitude, how does the CNS 'know' whether a stimulus is strong or weak?Problem 13
During a neurobiology lecture, a professor repeatedly refers to group A and group B fibers, absolute refractory period, and myelin sheath gaps. Define these terms.Problem 14
The velocity of nerve impulse conduction is greatest in a. heavily myelinated, large-diameter fibers, b. myelinated, small-diameter fibers, c. nonmyelinated, small-diameter fibers, d. nonmyelinated, large-diameter fibers.Problem 15
a. Describe the composition and function of the cell body. b. How are axons and dendrites alike? In what ways (structurally and functionally) do they differ?Problem 17
What is the polarized membrane state? How is it maintained? (Note the relative roles of both passive and active mechanisms.)Problem 18
Describe the events that must occur to generate an AP. Relate the sequence of changes in permeability to changes in the ion channels, and explain why the AP is an all-or-none phenomenon.Problem 22
When admitted to the emergency room, Sean was holding his right hand, which had a deep puncture hole in its palm. He explained that he had fallen on a nail while exploring a barn. Sean was given an antitetanus shot to prevent neural complications. Tetanus bacteria fester in deep, dark wounds, but how do their toxins travel in neural tissue?Problem 24
Local anesthetics block voltage-gated Na⁺ channels. General anesthetics are thought to activate chemically gated Cl⁻ channels, thereby rendering the nervous system quiescent while surgery is performed. What specific process do anesthetics impair, and how does this interfere with nerve impulse transmission?Problem 25
Rochelle developed multiple sclerosis when she was 27. After eight years she had lost a good portion of her ability to control her skeletal muscles. How did this happen?
