Myelin

Question 1

What stains myelin?

Answer 1

Osmium
White matter turns black

Question 2

What is white matter?
What is grey matter?

Answer 2

White matter- nerve tissue of CNS
- composed myelinated nerve fibers/axons
Gray matter- nerve tissue of CNS
- composed nerve cell bodies/dendrites

Question 3

What makes up CNS?

Answer 3

Brain and spinal cord

Question 4

Function of myelination?
Effect on resistance and capacitance?

Answer 4

Myelination improves conduction
Allows electrical signals to jump node to node- saltatory conduction
Increase resistance
Decrease capacitance

Question 5

What are gaps along myelinated axon called?

Answer 5

Node of Ranvier
High density ion channels

Question 6

Where do AP occur in myelinated axons?

Answer 6

Node of Ranvier

Question 7

What type of conduction does myelinated axons allow?

Answer 7

Saltatory conduction

Question 8

What is myelin sheath made of bio?

Answer 8

70% Lipid
30% Protein

Question 9

Function of myelin sheath?

Answer 9

Insulate axons

Question 10

What cells form myelin sheath?
CNS
PNS

Answer 10

CNS- Oligodendrocytes
PNS- Schwann

Question 11

What cells form myelination in CNS?

Answer 11

Oligodendrocytes

Question 12

What cells form myelination in PNS?

Answer 12

Schwann

Question 13

When does myelination begin?

Answer 13

Utero
3rd trimester

Question 14

Is myelin white or grey matter?

Answer 14

White

Question 15

What is grey matter?

Answer 15

Dendrites and synapses

Question 16

What is main function myelin?

Answer 16

increase speed of electrical impulses

Question 17

What nerves is myelination commonly found in?

Answer 17

Somatic

Question 18

What nerves unmyelinated commonly found? (3) Eg

Answer 18

Post ganglionic autonomic fibres
Olfactory
Interneurons
Eg Hypothalamus

Question 19

Label?

Answer 19