Homeostasis and the nervous system

Question 1

What is a stimulus

Answer 1

A change in the environment.

Question 2

What is the nervous system?

Answer 2

Means that humans can react to their surroundings and coordinate their behaviour.

Question 3

How does the nervous system react to a stimuli?

Answer 3

Receptors detect a stimuli and send electrical impulses down neurones to the nervous system.

CNS(central nervous system) sends electrical impulses to other neurons down to effectors.

Effectors carry out a response.

effectors -muscle which contracts/gland which secretes hormones

Question 4

What is a neurone?

Answer 4

nerve cell

thin

long

carry electrical impulses

and have branches

Question 5

How does nervous system react to an hot object?

Answer 5

receptor detects stimuli

electrical impulses pass from the receptor across the sensory neurone (connected to receptors
and receptors allow us to sense our environment.

end of sensory neurone- junction (synapse)
at synapse chemical released- diffuses across to a relay neurone in the (CNS)
triggers electrical impulse.

electrical impulse travels across relay neurone and reaches another synapse

chemical released

triggers electrical impulse in the motor neurone.

electrical passes from motor neurone to effector

effector= muscle contracts and pulls away from hot object

Question 6

Functions of reflexes?

Answer 6

Automatic and rapid

do not involve conscious of the brain.

Question 7

In reflexes does the conscious part of the brain make a decision?

Answer 7

no

Question 8

Why are reflexes important?

Answer 8

protect us from danger.