NEUROHISTO

Question 1

Oligodendrocytes

Answer 1

in white matter : myelin sheath formation
in grey matter: closely associated with neuron cell bodies, function as satellite cells

Question 2

Microglia

Answer 2

immune cells of CNS
phagocytic cells that enlarge and become mobile after injury to CNS

Question 3

Astrocytes

Answer 3

1. regulate composition of intercellular environment and entry of substances into it , provide structural support to neurons
2. metabolise neurotransmitters
3. mediate exchange of nutrients between metabolites and blood

Question 4

Schwann cells

Answer 4

• neuroglia in PNS
• myelinates nerve fibres
• provides electrical insulation
• faster conduction of nerve impulses along the axons

Question 5

Ependymal cells

Answer 5

• epithelial cells lining ventricles
• separate CSF from nervous tissue

Question 6

Peripheral nerve structure

Answer 6

• comprises bundles of myelinated axons
• surrounded by connective tissue elements
  1. epineurium
  2. perineurium
  3. endoneurium

Question 7

epineurium

Answer 7

connective tissue surrounding the entire nerve

Question 8

perineurium

Answer 8

a layer of dense connective tissue around each bundle of axons

Question 9

endoneurium

Answer 9

thin reticular layer that surrounds each individual nerve fiber and contains schwann cells

Question 10

structure of peripheral ganglion

Answer 10

• capsulated collections of neuron cell bodies
• contain satellite cells and connective tissue elements along with neurons

Question 11

axons

Answer 11

nerve fibres that conduct impulses away from the cell body

axons cytoplasm lacks ribo, rer, golgi

Question 12

dendrites

Answer 12

conduct impulses toward cell body

Question 13

excitatory synapse

Answer 13

neurotransmitter binds -> Na+ channels in post synaptic membrane open -> depolarisation -> AP fired

Question 14

inhibitory synapse

Answer 14

neurotransmitter binds -> K+/ cl- channels in postsynaptic membrane open -> hyperpolarisation of the membrane -> no AP