Simple reflexes

Question 1

What is the definition of a reflex

Answer 1

These are stereotyped involuntary reaction of the cns to specific sensory input. They bring a rapid response

Question 2

What are the 3 general functions of reflexes

Answer 2

Protection
Postural control
Homeostasis

Question 3

What are the 5 components of any reflex

Answer 3

Sensory receptor
Afferent 
Integration 
CNS
Efferent
Effector

Question 4

What are the neurones called that are in the integration centre

Answer 4

Interneurones

Question 5

What is a myotatic/ simple stretch reflex

Answer 5

A reflex that is involved in posture

Adjusts degree of skeletal muscle.

Question 6

What are the sensory receptors for myotatic reflex

Answer 6

Propioceptors

Question 7

An examples of myotatic reflex

Answer 7

Muscle spindle

Question 8

How does the muscle spindle work in terms of a reflex

Answer 8

• The sensory receptors sense stretch like weight
• the stretch stimilus sets up action potential that runs through the AFFERENT
• a EXCITATORY neurotransmitter is released
• efferent increases in activities
• muscle contracts to prevent damage like becoming ripped apart

Question 9

What is a reverse myotatic reflex , give an example

Answer 9

This reflex can occur in the golgi tendon organ
-nerve endings of the golgi ending are activated by pressure
- AP is generated which runs through the afferent
-AP is passed to the integration centre
-an EXCITATORY neurostransmitter is released
-interneurones are however INHIBITORY
-efferent activity goes down
-muscle does no contract
Example is weight lifters

Question 10

The name of a reflex that doesn’t use propioceptors

Answer 10

Crossed extensor reflex

Question 11

How does the crossed extensor reflex happen

Answer 11

-Pain is detected in the left leg (e.g from a pin)
- sensory receptors convert the stimulus to AP
-AFFERENT carries ap to the integration centre
-the interneurones are INHIBITORY and EXCITATORY
- EXCITATORY cause contraction
-INHIBITORY cause relaxation
-overall this causes the leg stepping on the pin to go up and the other leg to withstand the bodies weight.
This means that 2 responses occur simultaneously