Lecture 4 - Neural Tissue

Question 1

what are the neuronal support cells?

Answer 1

glial and endothelial

Question 2

what mediates the enteric nervous system

Answer 2

vagus nerve

Question 3

def: system with millions of neutrons stretching the length of the digestive tract

Answer 3

enteric nervous system

Question 4

what is the ratio of neurons to glial to endothelial cells?

Answer 4

5:3:1

Question 5

def: named for the predominance of axons, many of which are myelinated, contains few neuronal soma and few synapses

Answer 5

white matter

Question 6

in the brain: white matter lies _____ to grey matter

Answer 6

deep

Question 7

in H&E staining, the neuropil is so _______ that is difficult to study the morphology of any individual neuron

Answer 7

dense

Question 8

neurons have _____ prominent nuclei

Answer 8

large

Question 9

glial cells have _____ cytoplasm, prominent ______

Answer 9

pale cytoplasm, prominent nuclei

Question 10

def: silver staining technique that stains a limited number of neurons in their entirety

Answer 10

Golgi’s stain

Question 11

are granular neurons basophilic or eosinophilic?

Answer 11

basophilic

Question 12

how does cressyl violet interact with neurons?

Answer 12

it stains cell bodies, dendrites, but not axons since they do not contain RER

Question 13

what 3 neuronal ultrastructure details indicate the high metabolic activity of these cells?

Answer 13

1. dispersed chromatin
2. prominent nucleolus
3. substantial amounts of RER in dendrites and soma

Question 14

majority of the axon contains 2 prominent structural elements:

Answer 14

1. microtubules
2. neurofilaments

Question 15

what is the enzymatic immunohistochemistry method normally used for neuron-specific applications that shows microtubule elements?

Answer 15

beta-tubulin III

Question 16

in axonal cross section, microtubules are _______ relative to neurofilaments

Answer 16

large

Question 17

myelin is _____-______

Answer 17

electron dense

Question 18

is this a CNS axon or PNS axon: myelinated axons are densely packed and the myelin sheaths of neighbouring axons often make direct contact

Answer 18

CNS white matter

Question 19

is this a CNS axon or PNS axon: myelinated fibers are separated by connective tissue, small calibre axons are not myelinated and organized in Remak bundle, formed by non-myelinated Schwann cells

Answer 19

PNS nerves

Question 20

def: CT that encloses a nerve

Answer 20

epineurium

Question 21

def: CT that encloses a fascicle

Answer 21

perineurium

Question 22

def: CT that encloses the myelin sheath of a myelinated axon

Answer 22

endoneurium

Question 23

def: myelin formation: Schwann cells form individual myelin sheaths around axons, each Schwann cell associates with only one axon, Schwann cell nuclei are located on the outside of the sheath

Answer 23

PNS myelin formation

Question 24

def: myelin formation: oligodendrocytes form multiple myelin sheaths, each on separate axons

Answer 24

CNS myelin formation

Question 25

def: formed by apposition of the glial plasma membrane

Answer 25

intraperiod line

Question 26

def: formed by compaction of glial cytoplasm

Answer 26

major dense line

Question 27

def: specialized sites for electrochemical communication between neurons or between other effector cells such as muscle fibers

Answer 27

synapses

Question 28

def: terminates at a bulbous swelling or terminal bouton, separated from a plasma membrane of the opposed neuron or effector cell by a narrow intercellular gap of uniform width

Answer 28

presynaptic axon

Question 29

are terminal boutons myelinated?

Answer 29

no

Question 30

def: specialized synapse between motor axons and motor end plates of skeletal muscle

Answer 30

neuromuscular junction

Question 31

def: autoimmune disorder that leads to skeletal muscle weakness and fatigue, autoantibodies against the acetylcholine post synaptic receptors at the NMJ of skeletal muscle

Answer 31

myasthenia gravis