Nervous Tissue

Question 1

Neuron

Answer 1

Basic functional unit that receives and transmits nerve impulses; consists of:
-Cell body
-Dendrites
-Axon

Question 2

Cell body

Answer 2

Contains:
-large nucleus surrounded by abundant RER with Nissl bodies
-dendrite processes from soma (site for synapses)
-axon to transmit signals to neurons or cells of effector organs. Originates from soma at axon hillock and ends in terminal arborization to form synapses

Question 3

Lipofuscin

Answer 3

Fine yellow-brown pigment granules composed of residues of lysosomal digestion that accumulates in cytoplasm; considered an aging/wear and tear pigment

Question 4

Neuroglia

Answer 4

Protect neurons and support neuronal survival and activities; participate in regulation of neuronal propagation of impulses
Gap junctions occur between neuroglial cells

Question 5

4 kinds of CNS glial cells

Answer 5

Oligodendrocytes
Astrocytes
Microglia
Ependymal cells

Question 6

2 kinds of PNS glial cells

Answer 6

Neurolemmocytes (Schwann cells)
Satellite cells

Question 7

Oligodendrocytes

Answer 7

Produce and maintain myelin for myelinated axons
Smaller somas than astrocytes
Multiple processes that produce myelin

Question 8

Astrocytes

Answer 8

Provide structural and metabolic support to neurons
Remove ions and NT’s that have been released in extracellular space
Release glucose for neuronal energy metabolism
Help maintain BBB (blood-brain barrier) - continuous layer over CNS capillaries
Form cellular scar tissue (glial scar) for damaged areas

Question 9

Microglia

Answer 9

Small cells with short, irregular processes
Phagocytic - remove debris, viruses, and other microorganisms

Question 10

Ependymal cells

Answer 10

Columnar to cuboidal cells lining ventricles of brain and central canal of spinal cord
Selective barrier between brain parenchyma and CSF
Ciliated in some areas to facilitate movement of CSF

Question 11

Neurolemmocytes (Schwann cells)

Answer 11

Produce myelin sheaths outside of CNS
Plasma membrane of neurolemmocyte wraps around segment of axons many times - myelinated axons
Gap between adjacent neurolemmocytes is called Node of Ranvier

Question 12

Satellite cell

Answer 12

Collections of neuronal cell bodies outside of CNS
Found in ganglia
Small support cells that form a layer over surface of neuronal cell bodies
Provide trophic support for neurons and regulate their microenvironment

Question 13

White matter

Answer 13

Main component is myelin from myelinated axons
Few neuronal cell bodies in - astrocytes and microglia are present

Question 14

Gray matter

Answer 14

Consists of abundant neuronal cell bodies and dendrites
Where most of synapses occur
Astrocytes and microglia are present

Question 15

Meninges

Answer 15

Specialized membranes that provide protection, physical stability, and shock absorption for CNS
-Dura mater
-Arachnoid
-Pia mater

Question 16

Choroid plexus

Answer 16

Folds of tissues that extend into ventricles of the brain
Produces CSF

Question 17

Three layers of connective tissue

Answer 17

-Epineurium
-Perineurium
-Endoneurium

Question 18

Epineurium

Answer 18

Outermost layer; dense irregular collagenous connective tissue; covers the entire nerve

Question 19

Perineurium

Answer 19

Surrounds bundles of axons; dense irregular collagenous connective tissue; thinner than epineurium

Question 20

Endoneurium

Answer 20

Surrounds each individual myelinated axon; reticular fibers

Question 21

Myenteric ganglion

Answer 21

Collection of neuronal cell bodies located in the tunica muscularis of intestine; automatic motor ganglion