Peripheral Nerve

Question 1

Connective tissue layers of a nerve? (3 layers)

Answer 1

endoneurium - surrounds sensory neuron
perineurium - surrounds one fascicle
epineurium - surrounds groups of fascicles

Question 2

5 types of sensory receptors?

Answer 2

Meissner corpuscle
Ruffini’s corpuscles
Pacinian corpuscle
Merkel’s disks
Free nerve endings

Question 3

Meissner corpuscle?

Answer 3

fast adapt to change in pressure/vibrations
sensitive

Question 4

Ruffini’s corpuscles

Answer 4

sensitive to stretch
slow adapt but less sensitive

Question 5

Pacinian corpuscle

Answer 5

stimulus = layers to slide against each other
rapid adapt but less sensitive

Question 6

Merkel’s disks

Answer 6

relay ongoing pressure
- release neurotransmitter
- slow adapt

Question 7

Free nerve endings

Answer 7

sensory neuron dendrites are free

Question 8

Purpose of myelination?

Answer 8

insulates axon
increase speed of transmission

Question 9

Cells that myelinate CNS vs PNS?

Answer 9

Oligodendrocytes – form several myelin sheath
Schwann cells – form one myelin sheath
— insulate unmyelinated fibers (separate axons)
— Schmidt-Lanterman clefts

Question 10

Saltatory conduction?

Answer 10

Nodes of Ranvier = depolarize membrane (AP)
Internode = passive spread btwn AP (myelinated)

Question 11

Neuromuscular junction?

Answer 11

external lamina with neurotransmitter receptors invaginate = synaptic cleft