Nervous System and Nervous Tissue

The nervous system has two principal divisions, the central nervous system and the ____.

• peripheral nervous system

• somatic nervous system

• parietal nervous system

• lateral nervous system

Nerve cells that conduct impulses from the central nervous system to muscles and glands are ____ neurons.

• efferent

• afferent

• inter

• sensory

Sacs that store chemicals in the axon terminals are synaptic ____.

• vesicles

• receptors

• ion channels

• enzymes

A covering around axons, which is produced by neuroglia, is called the ____ sheath.

• myelin

• nervous

• glial

• astrocyte

The neurons in the walls of the organs of the digestive system form _______.

• enteric plexuses

• ganglia

• nuclei

• tracts

The gaps in the myelin sheath along axons are called _____.

• nodes of Ranvier

• saltatory nodes

• myelin gaps

• synapses

The sodium-potassium pump is a(n) _______ transport mechanism.

• active

• passive

• diffusion

• osmosis

-70 mV is the continuous voltage in neurons during _______ membrane potential.

• resting

• threshold

• depolarization

• repolarization

The critical level of depolarization that has to be reached for an action potential to occur is the _______.

• resting potential

• threshold potential

• depolarization

• repolarization

• hyperpolarization

When the polarity of a membrane becomes more negative than the resting membrane potential, the membrane is considered to be ____.

• depolarized

• repolarized

• hyperpolarized

• at threshold potential