BIOLOGICAL BASES OF BEHAVIOR
THE NERVOUS AND ENDOCRINE SYSTEMS
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
I, II and III
|
|
I, II and IV
|
|
I, III and IV
|
|
II, III and IV
|
Detailed explanation-1: -The characteristic properties of the nerve impulse are: electrical excitability; non-decremental or uniform conduction rate of impulse under uniform conditions; all-or-none response; and absolute refractoriness during response.
Detailed explanation-2: -By acting as an electrical insulator, myelin greatly speeds up action potential conduction (Figure 3.14). For example, whereas unmyelinated axon conduction velocities range from about 0.5 to 10 m/s, myelinated axons can conduct at velocities up to 150 m/s.
Detailed explanation-3: -Myelin can greatly increase the speed of electrical impulses in neurons because it insulates the axon and assembles voltage-gated sodium channel clusters at discrete nodes along its length.
Detailed explanation-4: -Nerve impulse flows more rapidly in Myelinated nerve fiber than in the Non-nucleated fibers. In myelinated fibers the nerve impulse jumps from one node of Ranvier to another, thus it is faster.