Nervous Tissue

Question 1

what are 2 other names for cell body?

Answer 1

soma and perikaryon

Question 2

what is another term for RER in neurons?

Answer 2

Nissl substance

Question 3

why can it be hard to see dendrites and axon on slides?

Answer 3

due to lack of nissl substance

Question 4

describe dendrites

Answer 4

branches from the soma that are connections from other neurons

Question 5

how many axons per neuron (typically)?

Answer 5

one

Question 6

where is the white matter in the cerebral cortex? gray matter?

Answer 6

white matter- inner

gray matter- outer

Question 7

what composes the white matter?

Answer 7

mostly myelinated axons

Question 8

what composes the gray matter?

Answer 8

neurons and glia

Question 9

what are the 3 layers of the cerebellum?

Answer 9

outer- molecular layer
middle- Purkinje layer
inner- granular layer

Question 10

what is the appearance of Purkinje cells with nissl stain?

Answer 10

only the soma is visible

Question 11

what is the appearance of Purkinje cells with golgi (silver) stain?

Answer 11

see dendritic tree extending toward outer, molecular layer

Question 12

what is the shape of gray matter in the spinal cord?

Answer 12

“H”

Question 13

compare the location of white and gray matter in each the brain and spinal cord

Answer 13

brain- outer-gray, inner-white

spinal cord- outer- white and inner-gray

Question 14

where are the motor neurons found in the spinal cord?

Answer 14

ventral horn

Question 15

what is another name for a collection of axons in the PNS?

Answer 15

nerve

Question 16

why do axons stain lightly?

Answer 16

high lipid content

Question 17

where are motor neuron cell bodies? axons?

Answer 17

cell body-CNS

axon-PNS

Question 18

where does the PNS begin?

Answer 18

outside of the spinal cord, in the spinal canal where sensory axons enter and motor axons leave the spinal cord

Question 19

what is the shape of a sensory ganglion’s axon?

Answer 19

T-shaped axon with long peripheral branch that goes to body, long central branch that enters spinal cord and short stem that connects to soma

Question 20

where are the cell bodies of sensory ganglia?

Answer 20

in the dorsal root ganglia

Question 21

where is the DRG located?

Answer 21

intervertebral foramen of the vertebral column

Question 22

describe the development of sensory ganglia axons

Answer 22

bipolar in early development, then 2 axons merge to form pseudo unipolar structure

Question 23

what is a ganglion?

Answer 23

a small collection of neurons in the PNS

Question 24

describe postganglionic neurons?

Answer 24

short dendrites and unmyelinated axons to smooth muscle and glands

Question 25

how can DRG be differentiated from autonomic ganglion microscopically?

Answer 25

1- satellite cells more prominent in DRG | 2- dendrites present in autonomic ganglia, asbent in DRG

Question 26

what covers unmyelinated axons?

Answer 26

cell membrane of Schwann cells

Question 27

what is another term for myelin layers?

Answer 27

lamellae

Question 28

how are Nodes of Ranvier seen in longitudinal section?

Answer 28

appear as tapered areas of myelin

Question 29

what is a synaptic bouton?

Answer 29

comtat point of axon with another neuron

Question 30

what is the small space between bouton and dendrite?

Answer 30

synaptic cleft

Question 31

what embryologic tissue is the source of most CNS neuroglial cells?

Answer 31

neuroectoderm (except for microglia)

Question 32

what is the function of oligodendroglia?

Answer 32

produce myelin in CNS

Question 33

what is the structure and function of fibrous astrocytes?

Answer 33

in white matter, long and slender processes | induce formation of BBB

Question 34

what is the structure and function of protoplasmic astrocytes?

Answer 34

in gray matter, thick and bushy processes | induce formation of BBB

Question 35

what is the function of ependymal cells?

Answer 35

line ventricles in brain and central canal or spinal cord and involved in production of CSF

Question 36

what are microglia?

Answer 36

macrophages that enter the CNS during development and phagocytize injured tissue

Question 37

what is the source of microglia?

Answer 37

bone marrow

Question 38

how many axons does a single Schwann cell myelinate?

Answer 38

one

Question 39

how many axons does a single olidodendroglia cell myelinate?

Answer 39

several

Question 40

what are Schmidt-Lantermann Clefts?

Answer 40

areas of disrupted myelin in PNS

Question 41

what are the functions of satellite cells?

Answer 41

assist in regeneration after nerve injury

Question 42

where are satellite cells found?

Answer 42

around neurons in ganglia like DRG or autonomic ganglia

Question 43

what is the embryologic origin of peripheral glial cells?

Answer 43

neural crest cells

Question 44

what types of fibers are carried by peripheral nerves?

Answer 44

motor and sensory

Question 45

what is the outer covering that covers bundles of fascicles?

Answer 45

epineurium

Question 46

what is the perineurium?

Answer 46

covers each fascicle and extends between fascicles, essential to blood-nerve barrier

Question 47

what is the inner covering that extends within fascicles but outside of myelin?

Answer 47

endoneurium

Question 48

what is an astrocytoma?

Answer 48

tumor or neuroglial cells

Question 49

what stain is used to identify astrocytomas?

Answer 49

GFAP IHC stain

Question 50

what are schwannomas?

Answer 50

benign tumors of schwann cells (Ex- acoustic neuroma)

Question 51

what is gliosis?

Answer 51

proliferation of astrocytes due to damage to CNS

Question 52

what is an ependymoma?

Answer 52

tumor of ependymal cells