Muscle reflexes: Control of posture Flashcards

1
Q

How does the feedback loop work?

A

Muscle spindle detects length in a muscle
Feeds to spinal cord
sends effector to muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a length trasnducer

A

Spindle in parallel with muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are intrafusal fibres

A

designed to monitor length in muscle

contractile elements are gone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What innervates intrafusal fibres

A

Innervated by type 1a (thick and II (thin) for sensory inn

innervated by dynamic and static gama efferernts for motor inn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How do fibres sense velocity

A

Fast adapting and very quickly stop firing as soon as stimulus ends
produce a phasic response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is meant by alpha-gamma coactivation

A

Contract muscle with alpha motor neurone also contract spindle with gamma motor meurone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does the alpha- gamma coactivation do?

A

Prevents spindle from being unloaded

gamma neurones can determine how toned the muscles are

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the stretch reflex

A

Monosynaptic reflex but recriprocal innervation
muscle contracts against stretch
smooths and damps muscle movement
signals length and velocity of muscles centrally via the spinocerabellar adn dorsal tracts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does the golgi tendon organ insure?

A

tendon doesn’t stretch and allows us to control muscle force finely aswell as length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the crossed extensor reflex

A

An opposite side to stimulus to stiffen the body and stabilise posture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens when we are walking

A
  • alternate contraction of flexors and extensors

central pattern generator in spine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly