nervous tissue

Question 1

name the 3 membranes that protect the CNS from deepest to superficial

Answer 1

pia mater, arachnoid membrane, dura mater (PAD)

Question 2

Epidural anesthetics are injected just outside the _____ mater to numb spinal nerves during certain surgical procedures.

Answer 2

dura

Question 3

what is the fluid that circulates within the membranes?

Answer 3

cerebrospinal fluid

Question 4

what neuronal cell bodies contribute to white matter?

Answer 4

axons

Question 5

what are localized clusters neurons may be found in?

Answer 5

nuclei

Question 6

what is the main functional unit of the nervous system?

Answer 6

cell body/perikaryon

Question 7

what is the long process of a neuron that extends from the cell body?

Answer 7

axon

Question 8

how the axon end in a terminal or and connect with another neuron?

Answer 8

synapse

Question 9

how can a neuron terminate on a muscle?

Answer 9

motor end plate

Question 10

what is a smaller processes that arises from the perikaryon?

Answer 10

dendrites

Question 11

describe the nucleus of a neuron

Answer 11

euchromatic, prominent nucleolus

Question 12

what are the ribosomes visible as blue granules abundant in the cytoplasm?

Answer 12

Nissl substance

Question 13

true or false: Dendrites will have cytoplasm with Nissl substance in them, however, the axon will not have Nissl substance

Answer 13

true

Question 14

what tissue do glial cells form?

Answer 14

c.t. in the nervous system

Question 15

name and describe the 3 basic types of glia

Answer 15

• Astrocytes- largest with prominent processes. Found close to blood vessels
• Oligodendrocytes-intermediate, ensheath axons. also called neurolemmocytes in the PNS
• Microglia-smallest with extensive processes. Arise from macrophages and therefore serve as immunomodulators

Question 16

what are aggregations of nerve cell bodies outside the CNS called?

Answer 16

ganglia

Question 17

where are dorsal root ganglia located?

Answer 17

beside the spinal cord

Question 18

what are sympathetic ganglia loacted?

Answer 18

outside vertebral column

Question 19

where are nerves (post ganglionic fibers)?

Answer 19

ganglia from sympathetic and dorsal root ganglia that are long and innervate a variety of tissues and organs

Question 20

where parasympathetic ganglia located?

Answer 20

close to or within the organs and their postganglionic fibers are very short

Question 21

what are aggregates of axons within the CNS?

Answer 21

tracts

Question 22

what are aggregates of axons within the PNS?

Answer 22

nerves

Question 23

what covers the axons in the PNS?

Answer 23

Schwann cells or neurolemmocytes

Question 24

what covers the axons in the CNS?

Answer 24

oligodendrocytes

Question 25

what is the distinction between myelinated and unmyelinated neurons?

Answer 25

one Schwann cell covers multiple axons in unmyelinated nerves, It wraps around a single axon over and over to form a thick covering called the myelin sheath in myelinated nerves

Question 26

what is the node of ranvier?

Answer 26

junction between 2 Schwann cells on the axon

Question 27

what are myelinated axons need for?

Answer 27

fast impulse transmission, muscles and joints

Question 28

what are unmyelinated axons needed for?

Answer 28

slow transmission, salivary glands

Question 29

how do you distinguish between myelinated and unmyelinated axons in a stain?

Answer 29

• myelinated axons will have neurokeratin around them and have a “candy cane” appearance in cross section
• Unmyelinated axons are wavy and do not have neurokeratin surrounding them