Neuro physiology Flashcards
(36 cards)
pseudo unipolar neurone - how many neurites?
one neurite that bifurcates
most excitable part of neurone
axon hillock and initial segment
Axon with a large/small? diameter can conduct an AP at greater velocity
Large diameter
lower resistance
Microglia: oligodendrocytes/schwann cells -which ones are found in the CNS?
CNS: oligodendrocytes
most excitable parts along an axon
nodes of ranvier (myelin sheath gaps)
name of nerve conduction in myelinated axons
saltatory conduction
most common excitatory and inhibitory transmitters in the CNS
excitatory: glutamate
inhibitory: GABA or glycine
inhibitory neurotransmission involves efflux of ?
K+
excitatory NTM involves influx of ?
Na+
LMN’s
alpha innervate ?-fusal fibres and gamma innervate ?-fusal fibres
alpha LMN’s innervate extra-fusal fibres
gamma LMN’s innervate intra-fusal fibres
where are golgi tendon organs located
at the junction of the muscle and tendon
what do golgi tendon organs monitor
changes in muscle tension
|»_space; protect muscle from overload
what type of sensory afferents innervate golgi tendon organs
1b
When 1b afferent is excited, is alpha-MN inhibited or excited?
alpha-MN INHIBITED by excitation of 1b afferent
what is the crossed extensor reflex
opposite leg extends to stop you falling over when the other leg flexes in response to noxious stimulus
Rubrospinal tract is responsible for limb ..?
flexors
Vestibulospinal tract is responsible for limb ..?
extensors
reticulospinal tract
which is medial - pontine or medullary?
which enhances antigravity reflexes?
pontine is medial, medullary is lateral
pontine enhances antigravity muscles»_space; contraction of lower limb
medullary opposes this»_space; relaxes antigravity muscles
State functions of each fibre type: A-alpha A-beta A-delta C
A-alpha: proprioceptors of skeletal muscle
A-beta: mechanoreceptors of skin
A-delta: pain and temperature
C: temperature, pain, itch
In what laminae do nociceptive A-delta and C fibres terminate
I and II (and also V for A-delta)
Nociceptive pathway: which causes primary and which causes secondary hyperalgesia a) Peripheral sensitisation b) central sensitisation which one plays a major role in heat?
Peripheral sensitisation > Primary hyperalgesia
- plays a major role in heat
Central sensitisation > secondary hyperalgesia
(underlies pain that persists after tissue healing)
what is viscerosomatic pain like?
sharp and well localised
what contains axons of the nerve cells - white matter or grey matter?
White matter contains axons
Grey matter contains cell bodies of the nerve cells
what does the central canal contain
CSF
