Chapter 2 (Histology Of The Nervous System )

Question 1

Negri bodies ?

Answer 1

Eosinophilic cytoplasmic inclusions seen in degenerating neurons in the Hippocampus and cerebellar cortex in patients with rabies

Question 2

Functions of neurofilaments , microfilaments and microtubules ?

Answer 2

Neurofilamemts : provides structural support for the neuron
Microfilaments : aid the motility of growth cones during development
And forms structural specializations at synaptic membranes
Microtubules : used in axonal transport

Question 3

The cytoplasm of the axon lacks what and contains what ?

Answer 3

Lacks :
Free polysomes
Nissl substance
Golgi apparatus

Contains :
Mitochondria
Smooth ER

Question 4

Fast anterograde axonal transport is dependent on ?

Answer 4

Kinesin

Question 5

Causes of disruption of anterograde axonal transport ?

Answer 5

Anoxia which affects mitochondrial oxidative phosphorylation
Anticancer agents as Colchicine and Vinblastine which depolymerize microtubules

Question 6

Retrograde axonal transport is dependant on ? Its function ?

Answer 6

Dynein

Returns intracellular material from synaptic terminal to the cell body to be recycled or digested by lysosomes
Permits communication between the synaptic terminal and cell body by transporting trophic factors emanating form the postsynaptic target or in the extracellular space

Question 7

Functions of the astrocytes ?

Answer 7

1- provide the structural support for the CNS
2- remove glutamate and K from the extracellular space
3- they have foot processes which contribute to the blood brain barrier by forming a glial-limiting membrane
4- they hypertrophy and proliferate after an injury to the CNS , filling up the extracellular space left by the degenerating neurons forming an astroglial scar

Question 8

Function of radial glia ?

Answer 8

Guide neuroblast migration during CNS development

Question 9

Source of microglia cells ?

Answer 9

Bone marrow monocytes which enter the CNS after birth

Question 10

The cells in the CNS that are targeted by the HIV virus ?

Answer 10

Microglia cells

Question 11

Cells that determine the chances of survival of CNS tissue graft ?

Answer 11

Microglia cells

Question 12

Components of the blood brain barrier ?

Answer 12

Capillary endothelial cells
Underlying basal lamina
Astrocytes
Pericytes

Question 13

Chromatolysis ?

Answer 13

Dispersion of the Nissl substance and swelling of the neuron cell body