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Flashcards in Structure of Nerve Tissue - X Deck (37):
1

Internerouns

Interconnect other neurons, 99.9% of all neurons

2

GVE - information pathway
**

Ventral root of spinal cord, through ventral root out to smooth and cardiac muscle, glands, etc
Two neuron chain

3

GSA - movement of information, how
**

Bring in information from the periphery/body to Spinal Cord.
Cell bodies located in Dorsal Root Ganglion
Information flows through the dorsal root into the dorsal horn of the spinal cord

4

Multipolar - def, e.g.
**

most common
1 axon, 2+ dendrites
motor neurons and interneurons

5

Cell Body - characteristics

large pale staining nucleus
dispersed chromatin
nucleoli
Lots of RER and Nissl bodies (free ribosomes)
numerous mitochondria

6

Unipolar/ psuedounipolar - def, e.g.

1 long axon divides close to cell body into 2 long axial branches
typically prokaryotic
eukaryotic evolution - DRG cells

7

Axon Hillock - def, significance

initial segment of axon w/o Nissl bodies or Golgi
sight of nerve impulse generation - very excitable

8

Bipolar - def, e.g.
**

1 axon, 1 dendrite
associated with receptors for special senses

9

Retrograde

towards cell body
Mediated by Dynein
viruses could be taken up nerve terminal and transferred int CNS
Rate : FAST

10

Anterograde - axonal transport

away from cell body
mediated by Kinesin
two rates : Slow (same as peripheral regeneration)
Fast

11

Neurofilaments - fxn

support
role in neuronal development and regeneration

12

Microfilaments - def, fxn

actin
Anchor
transfer molecules to/from cell membrane
Cause movement of growing axonal tips during development and regeneration

13

Microtubles
**

cylindrical assemblies of tubuli, with axonal transport proteins

14

Presynatic terminal - a..k.a
**

buton

15

Synapses - catergories
**

axo-dendritic (majority))
axosomatic
axoaxonic
dendrodentritic

16

Neuromuscluar junction
**

specialized synapses on skeletal muscle
ACH as nt
junctional folds on muscle fiber membrane

17

Neuroglial cells - fxn, types
**

support and myelination in PNS
Peripheral = Schwann and Satellite cells

18

Schwann Cells - fxn
**

Myelinate peripheral axons
Myelin sheath - concentric rings of Schwann around axon
also surrounds/nurtures unmyelinated axons
thicker myelin = faster conduction

19

DRG

contains cell bodies of pseudounipolar sensory neurons
cell bodies surrounded by satellite cells
NO synapses occur here

20

Schidmt-Laternams clefts - def., fxn

islands of Schwann cytoplasm bwtn lamellae of myelin
= characteristic fishbone appearance on LM
fxn - Intracelluar communication

21

Autonomic Ganglia - characterstics

Multipolar
Synapses OCCUR

22

Sateliite Cells - def, fxn

glial cells that surround peripheral ganglia
Maintain controlled local enviroment
Provide electrical insulation
Path for metabolic exchange

23

CT coverings on nerves

Epineurium
Perineurium
Endoneurium

24

Epineurium

Surround entire nerve

25

Node of Raniver
**

btwn two adjacent Schwann cells (no myelin)
intenodes - have myelin sheath
Nodes have high [Na+] resulting in fast impulse propagationsaltatry transmission 'jumping'

26

Perineurium

Surround fascicle ( bundle of nerve fibers)

27

Permeability barrier - a.k.a , fxn

blood-nerve barrier btwn perinuerial fibroblasts surrounding nerve fascile
maintains ionic environment of nerve fibers

28

Permeability barrier - a.k.a , fxn

blood-nerve barrier btwn perinuerial fibroblasts surrounding nerve fasicle
maintains ionic environment of nerve fibers

29

Kinesthesia

Detection of movement through space

30

Guillain-Barré syndrome

autoimmune condition - destroys Schwann cells by T cell response against peripheral myelin.
Loss of cutaneous sensation.
Symmetrical ascending weakness.
Pt can survive and recover

31

Nerve Injury Classification - +action
XX

mild compression - demyelination
nerve crush - axons disconnected
complete transection - whole nerve

32

Endoneurium

surround individual axons

33

Nerve Regenration
**

Rate slow - into distal stump
If damaged, some axons grow endoneurial tubes, reestablishes contact with muscle
If growths disorganized, can lead to painful traumatic neuroma at site of injury

34

anterograde Wallerian Denegeration
**

Distal to injury/cut
-axon swells, disintegrates, removed by macrophages
-Schwann cell dedifferetiate, breaking down myelin sheath and blood-nerve barrier
-Schwann cells secrete growth factors, divide and line up as guidance for new axon sprouts

35

Retrograde Chromatolysis
**

Proximal in cell bodies of origin
-Cell body swells
-Nucelus Shifts to periphery
-Nissl substance (RER) breaks down

36

GVA

wall of internal organs, glands and blood vessel to spinal cord

37

GSE

CNS to voluntary skeletal muscle
cell bodies in ventral horn, exit through ventral roots