B1.2.1 ~ The Nervous System

Question 0

Whats the central nervous system (CNS)?

Answer 0

Brain and spinal cord.

Question 1

Whats stimulus?

Answer 1

A stimulus is a change in the environment that we can detect.

Question 2

What are receptors?

Answer 2

Receptors are cells that can detect a particular stimulus. Sense organs contain a lot of these receptor cells.

Question 3

What are the three neurones?

Answer 3

Sensory Neurone.
Relay Neurone.
Motor Neurone.

Question 4

Whats an effector?

Answer 4

It’s the organ that makes the response. This could be a muscle or a gland that responds by releasing a chemical, such as a hormone.

Question 5

What are sensory neurones?

Answer 5

Sensory neurones transmit messages from the sense organ such as the eye or nose to the brain or spinal cord.

Question 6

What are motor neurones?

Answer 6

Motor neurones transmit messages from the brain and spinal cord to the muscles and glands.

Question 7

Whats a synapse?

Answer 7

A synapse is a junction between 2 neurones. When a nerve impulse reaches a synapse a chemical transmitter is released. The chemical diffuses across the gap and sets up the nerve impulse in the next neurone.

Question 8

What are reflexes?

Answer 8

Reflex actions are automatic responses to stimuli that could cause your body harm. Reflexes do not involve the brain, they are processed in the spinal cord. That’s why they are quicker than normal responses.