Receptors And Reflex Arc

Question 1

Three main types of neurone

Answer 1

Sensory
Relay
Motor

Question 2

Sensory neurones

Answer 2

Carry impulses from receptors -> CNS

Question 3

Relay neurones

Answer 3

Found entirely within the CNS and connect sensory and motor neurones

Question 4

Motor neurones

Answer 4

Carry impulses from the CNS -> effectors

Question 5

What is a reflex arc

Answer 5

A pathway along which impulses are transmitted from a receptor to an effector without involving conscious regions of the brain

Question 6

Example of a reflex arc step by step

Answer 6

1) A burn is detected by a pain receptor in the skin
2) Sensory neurone sends electrical impuses to the spinal cord (coordinator)
3) Electrical impulses are passed on to relay neurones in the spinal cord
4) The relay neurone connects the motor neurone and passes the impulses on
5) The motor neurone carries the impulses to the muscle in the leg (the effector)
6) Impulses cause the muscle to contract and pull the leg up and away from the hot object

Question 7

Reflex pathway in steps simple

Answer 7

Stimulus
receptor
Sensory neurone
Relay neurone
Motor neurone
Effector
Response