Functional Organization of Nervous Tissue

This portion of the motor division of the nervous system conducts action potentials from the central nervous system to skeletal muscle fibers.

• a. afferent

• b. autonomic

• c. somatic

• d. sympathetic

These cells conduct action potentials from one neuron to another within the CNS:

• a. sensory (afferent) neurons

• b. motor (efferent) neurons

• c. interneurons (association) neurons

• d. bipolar neurons

Axons terminate by branching to form small extensions with enlarged ends which are called this:

• a. dendrites

• b. neuron cell bodies

• c. presynaptic terminals

• d. postsynaptic membranes

• e. axon hillocks

These cell types produce and help circulate cerebrospinal fluid:

• a. astrocytes

• b. microglia

• c. ependymal cells

• d. Schwann cells

• e. oligodendrocytes

These statements about unipolar neurons are all true except:

• a. most are sensory neurons

• b. have a single process extending from the cell body

• c. located in the eye and nasal cavity

• d. have no dendrites

This statement best describes the myelin sheath:

• a. made of Schwann cells (neurolemmocytes)

• b. covering surrounding an axon

• c. provides insulation from other axons

• d. helps conduct the action potential more rapidly

• e. all are true

Compared to the outside of the resting plasma membrane, the inside surface of the membrane is this:

• a. positively charged

• b. electrically neutral

• c. negatively charged

• d. continuously reversing so that it is positive one second and negative the next

Because of the sodium-potassium pump, there are:

• a. more K+ outside the cell than inside and more Na+ inside the cell than outside

• b. more K+ inside the cell than outside and Na+ outside the cell than inside

• c. more K+ and Na inside the cell than outside

• d. more K+ and Na outside the cell than inside

The resting membrane potential results when the tendency for these ions to diffuse out of the cell is balanced by their attraction to opposite charges inside the cell:

• a. Na+

• b. K+

• c. Cl-

• d. negatively charged proteins

• e. Ca2+

Hyperpolarization, which is an increase in membrane potential, can be caused by this:

• a. opening of Cl- gated channels

• b. opening of Ca2+ gated channels

• c. opening of Na+ gated channels

• d. increase of extracellular K+