Nerves I and II Flashcards
(21 cards)
1
Q
describe the neural cell body
A
- called soma
- euchromatic nucleus
- Nissl bodies
- stacks of rER
- numerous mitochondria
- large perinuclear Golgi
2
Q
A
3
Q
describe dendrites
A
- carry information towards the cell body
- greater diameter than axons
- unmyelinated
4
Q
describe axons
A
- carry information away from cell body
- 1 axon for each neron
- axon hillock
- conical projection of cell body
- devoid of Nissl bodies
- lacks large organelles
- plasma membrane = axolemma
- contents = axoplasm
5
Q
describe Golgi Type I and II neurons
A
- Golgi Type I neurons
- motor nuclei of CNS
- axons more than 1 meter long
- skeletal muscle
- Golgi Type II neurons
- short axons
- Golgi cells in cerebellum
- interneurons
6
Q
describe the axon transport systems
A
- Anterograde transport:
- cell body to periphery
- kinesin
- retrograde transport:
- axon terminal and dendrites to cell body
- Dynein
7
Q
name the peripheral vs central nueroglial cells
A
- peripheral neuroglial:
- Schwann cells
- satellite cells
- central neuroglial:
- microglia
- ependymal cells
- astrocytes
- oligodendrocytes
8
Q
describe Schawnn cells
A
- originate from neural crest cells
- responsible for myelination in PNS
- only axon hillock and terminal arborizations are free of myelin
- multiple layers of Schwann cell membrane wrapped concentrically around an axon
9
Q
A
myelinated nerve fiber
10
Q
describe demyelinating diseases
A
- Guillan-Barre Syndrome
- disease of PNS
- nerve fibers accumulate lymphoctes, macrophages and plasma cells and leads to loss of muscle coordination and cutaneous sensation
- MS
- preferential damage to myelin – detach from axon and destroyed
- damage to oligodendrocytes
- 3 histological stages in the demyelinating process:
- myelin breakdown associated with lymphocyte and macrophage infiltration of affected area - plaque
- proliferation of astrocytes - gradual infiltration of astrocytes into demyelinating area
- reduced cellularity, astrocyte reduce in size
11
Q
A
pathology of MS
- W = white matter
- D = demyelinating region
- L = lymphocytes
12
Q
describe satellite cells
A
- surround ganglionic neuronal cell bodies
- cuboidal
- form complete layer around cell body
- only nuclei are visible
- form complete layer around cell body
- originate from neural crest cells
- analogous to Schwann cells
- insulation
- nutrition
13
Q
A
- satellite cells
14
Q
describe oligodendrocytes
A
- derived from the neural tube
- CNS myelin formed by:
- concentric layers of oligodendrocyte plasma membrane
15
Q
A
myelin sheath of the CNS made by oligodendrocytes
16
Q
describe astrocytes
A
- largest of glial cells
- derived from the neural tube
- 2 kinds are seen:
- protoplasmic
- prevalent in gray matter
- fibrous
- prevalent in white matter
- protoplasmic
- have elaborate processes extending b/t vessels and neurons
- may have a role in regulating tight junctions of BBB
17
Q
A
astrocytes
18
Q
describe microglia
A
- part of mononuclear phagocytic system
- derived from monocyte precursor
- present in small numbers
- proliferate during injury/disease
- actively phagocytic
- secrete immunoregulatory cytokines that dispose of unwanted cellular debris
19
Q
A
microglia
20
Q
describe ependymal cells
A
- produce and secrete CSF
21
Q
A
ependymal cells
