11) The largest and most numerous of the glial cells in the central nervous system are the

A) astrocytes.

B) Schwann cells.

C) oligodendrocytes.

D) microglia.

E) ependymal cells.

12) The myelin sheaths that surround the axons of some of the neurons in the CNS are formed by

A) astrocytes.

B) Schwann cells.

C) oligodendrocytes.

D) microglia.

E) ependymal cells.

13) Small phagocytic glial cells, which are derived from white blood cells, are called

A) astrocytes.

B) Schwann cells.

C) oligodendrocytes.

D) microglia.

E) ependymal cells.

14) The neurilemma of axons in the peripheral nervous system is the outer layer of

A) astrocytes.

B) ependymal cells.

C) oligodendrocytes.

D) microglia.

E) Schwann cells.

15) Clusters of rough endoplasmic reticulum and free ribosomes are known as

A) neurofilaments.

B) neurofibrils.

C) synapses.

D) Nissl bodies.

E) microglia.

16) Branches that sometimes occur along the length of an axon are called

A) action potentials.

B) synaptic knobs.

C) collaterals.

D) hillocks.

E) synapse.

17) Neurons that have one axon and one dendrite with the soma between them are called

A) polypolar.

B) unipolar.

C) bipolar.

D) tripolar.

E) multipolar.

18) Neurons that have two or more dendrites and a single axon extending away from the soma are called

A) polypolar.

B) unipolar.

C) bipolar.

D) tripolar.

E) multipolar.

19) Which neuroglial cells produce CSF in some regions of the brain?

A) microglia

B) Schwann cells

C) ependymal cells

D) oligodendrocytes

E) astrocytes

20) Bundles of CNS axons that share a common origin, destination, and function are called ________.

A) the cortex

B) centers

C) nuclei

D) tracts

E) ganglia