B1- Nervous System

Question 1

What does the nervous system do

Answer 1

Enables humans to react to their surroundings

Question 2

What are receptors

Answer 2

Cells that detect stimuli (changes in the environment)

Question 3

Examples of receptors and the stimuli they detect

Answer 3

Receptors in eye are sensitive to light

Receptors in ears are sensitive to sound

Receptors on tongue and nose are sensitive to chemicals that let us taste and smell

Receptors in skin are sensitive to touch, pressure pain and temp change

Question 4

What do light receptors contain

Answer 4

Nucleus
Cytoplasm
Cell membrane

Question 5

Role of sensory neurones

Answer 5

Carries signals from receptors to spinal cord and brain

Question 6

Role of motor neurone

Answer 6

Carries signals from CNS to effectors

Question 7

Role of relay neurones

Answer 7

Carry message from CNS to another

Question 8

Role of synapses

Answer 8

Gap where two neurones meet

Question 9

What happens in a reflex action

Answer 9

Impulse passes along a sensory neurones to the CNS
Impulse reaches synapse between sensory neurones and relay
Chemical released at synapse causing impulse to be sent along neurone
Chemical releases between relay and motor neurone. Triggers impulse to pass down to motor neurone
Impulse reaches effector (muscle or gland) which contracts leading to response