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Flashcards in DLA 27 +DLA 28 Deck (19)
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1

What is the BBB?

Protects the CNS from imbalances in surrounding
environment- electrolytes, hormones, metabolites

complex tight junction, continuous basal lamina

surrounded by foot processes of astrocytes

can lose effectiveness during certain diseases

some parts have no barrier (homeostatic reasons)

2

What is multiple sclerosis?

autoimmune disorder that targets myelins basic protein
CNS

3

What are the three stages of the demyelinating process?

1) Myelin breakdown associated with lymphocyte and macrophage infiltration of affected area- plaque

2) Proliferation of astrocytes – gradual infiltration of astrocytes intodemyelinating area

3)Reduced cellularity, astrocyte reduce in size

4

response to injury in CNS?

Absent/slow regeneration-blood brain barrier
• Ineffective phagocytosis
• Myelin debris persists
• Astrocyte scarring

5

response to injury in PNS?

Rapid regeneration
• Macrophages migrate from blood
• Complete interruption of blood nerve barrier

6

Wallerian degeneration (anterograde)?

degeneration of axon distal to site of injury

7

PNS anterograde degeneration?

degeneration takes a few days
-Dedifferentiation of Schwann cells and alignment.\

8

CNS anterograde degeneration?

degeneration takes several weeks
-Loss of axon contact initiate apoptotic cell death

9

chromatolysis?

loss of Nissl substance from cell
body
• 1-2 days after injury
– Changes in cell body are
proportionate to:
• amount of axoplasm lost
from injury
– large amount =CELL DEATH

10

Guillian barre?

damage to the schwann cells

Nerve fibers - Large,accumulation of
lymphocytes,,macrophages and,plasma cells

Ascending muscle,loss of muscle co–ordination &
cutaneous sensation

11

The autonomic nervous system innervates what tissues?

1. smooth muscle

2. cardiac muscle

3. glands

12

What are the two major divisions of the autonomic nervous system?

the sympathetic and parasympathetic

13

functions of the sympathetic nervous system?

fight, flight, or freight mode

14

function of the parasympathetic NS?

rest and digest mode

15

What are somatic motor neurons?

One long, heavily myelinated axon extending from the CNS to the effector

16

autonomic motor neurons?

Two Neuron System
•A lightly myelinated preganglionic neuron with the cell body in the CNS
•An unmyelinated postganglionic neuron with the cell body in autonomic ganglion in the PNS

17

Where are parasympathetic ganglia found?

near or in the walls of target organs

18

Where are the sympathatic ganglia found?

lateral to the spine

skull to the coccyx

19

where are the preaortic ganglia found?

The abdomen