L18: Reflexes

Question 1

What are the 3 types of reflexes

Answer 1

Involuntary
Voluntary
Rhythmic e.g diaphragm

Question 2

What happens when the posture is disturbed when the body moves

Answer 2

A feedback and feed forward system occurs to adjust the posture

Question 3

What does out postural muscle need to do for stability

Answer 3

• maintain tone to counteract gravity

- corrective reflexes to maintain stability

Question 4

Does the activity of skeletal muscle depend on somatic or autonomic system

Answer 4

Somatic

Question 5

How does the skeletal muscle move

Answer 5

Plan to move is initiated in the motor cortex
Action is programmed
Primary motor cortex initiated the movement of the skeletal muscle

Question 6

How is the skeletal muscle controlled for storement in the future

Answer 6

By sensory input

Question 7

What are the sensory inputs

Answer 7

Visual system
Vestibular system
Skin receptors
Propioceptors

Question 8

What do propioceptors sense

Answer 8

Muscle tension

Question 9

What are propiceptors

Answer 9

Receptors in muscle

Question 10

Where are propiceptors found

Answer 10

In muscle

Question 11

What are somatic motor reflexes

Answer 11

Stereotypic movements elicited by specific sensory stimuli

Question 12

What type of fibres are muscle spindle

Answer 12

Intrafusal muscle

Question 13

What is the role of intrafusal muscle spindle

Answer 13

A sensory organ that senses

Question 14

What are the 2 regions of the muscle spindle

Answer 14

Central region

Polar region

Question 15

What does the central region of the muscle spindles involve

Answer 15

Primary and secondary sensory afferents that feed to the brain

Question 16

What does the polar region of the muscle spindle involve

Answer 16

Gamma motor neurones that adjust sensitivity of the spindle

Question 17

What group of sensory fibres are primary afferents

Answer 17

Group 1a

Question 18

What group of fibres are secondary fibres

Answer 18

Group 2 afferents

Question 19

What happens when a muscle spindle is stretched

Answer 19

Fire action potential to the spinal cord
Alpha motor neurone signals to extrafusal muscle
Muscle contracts

Question 20

What is the role of gamma efferents

Answer 20

Correct the loss of muscle spindle sensitivity

Question 21

What happens in a golgi tendon organ

Answer 21

Golgi tendon organ detects stretch

Too munch stretch switches it off to prevent out stretching

Question 22

What is the alpha gamma co activation in the stretch reflex

Answer 22

When the muscle shortens the spindle is relieved
Sensory axons that innervate the spindle may stop
Gamma motor neurones become activated at the same time
The gamma motor neurone contract to maintain tension on the central region

Question 23

What do muscle spindles sense

Answer 23

Stretch of the muscle

Question 24

What do golgi tendon organs sense

Answer 24

Tendon stretch

Question 25

What does muscle spindle cause

Answer 25

Causes muscle activation

Question 26

What do golgi tendon organs cause

Answer 26

Muscle inhibition

Question 27

What type of fibres do alpha motor neurone innervate

Answer 27

Extrafusal fibres

Question 28

What type of fibres do gamma motor neurone innervate

Answer 28

Intrafusal fibres within the extrafusal fibre

Question 29

What is the stimulus of the stretch reflex

Answer 29

A load e.g someone pouring water into your cup that you are holding