The Nervous System

Question 1

What should all control systems include?

Answer 1

Receptors, coordination centre and effectors

Question 2

What do receptors do?

Answer 2

Detect stimuli(touch)

Question 3

What does the ‘coordination centre’ do?

Answer 3

Receives and processes information from receptors around the body

Question 4

Give an example of the coordination centre

Answer 4

Brain, spinal cord or pancrease

Question 5

What do effectors do?

Answer 5

Bring about responses which restores optimum levels( body temp, blood sugar levels)

Question 6

Give an example of effectors

Answer 6

Muscles and glands ( they include muscle contradictions or hormone release)

Question 7

What are nerve cells called?

Answer 7

‘Neurones’

Question 8

What are neurones function?

Answer 8

To carry electrical impulses from one place to another

Question 9

What are a bundle of neurones called?

Answer 9

A nerve

Question 10

What are the 3 types of neurone?

Answer 10

Sensory
Motor
Relay

Question 11

Name some features of the nerve cells

Answer 11

Axon( long fibre), myeline sheath
Dendrons

Question 12

What’s the function of the axon?

Answer 12

Long so they can carry messages up and down the body

Question 13

What’s the function of the myeline sheath?

Answer 13

Insulates the axon

Question 14

What’s the functions of dendrons?

Answer 14

Branch further as dendrites at each end- receive incoming impulses from other neurones

Question 15

What’s a synapse?

Answer 15

The gap between 2 neurones when they meet

Question 16

State what happens when an electrical impulse moves from one neurone to another

Answer 16

1) electrical impulse travels along the first axon
2) this trigger the nerve-ending of a neurone to release chemical messengers caused neurotransmitters
3) these chemicals diffuse across the synapse+bind with receptor molecules on the membrane of the 2nd neurone
4)receptor molecules on the 2nd neurone bind to specific neurotransmitters released from 1st neurone
5)this stimulates the 2nd neurone to transmit the electrical impulse

Question 17

What do receptor cells detect?

Answer 17

A change in the environment( stimulus) and start electrical signals along neurones- this moves to central nervous system -CNS.

Question 18

What happens after the receptor cell moves the electrical signals to the CNS?

Answer 18

The relay neurone coordinates the responses, sending messages back along different neurones to the muscles

Question 19

What do the effectors do after the CNS sent the response?

Answer 19

Muscles contract/relax
Glands secrete hormones

Question 20

Give what happens receptors to response

Answer 20

Stimulus
Receptor(sensory neurone)
CNS/relay neurones
Motor neurones
Effectors
Response

Question 21

What’re receptors?

Answer 21

Groups of specialised cells-detect a change in the environment and stimulate electrical impulse in response

Question 22

Give the pathway of a reflex

Answer 22

Stimulus
Receptor
Sensory neurone
Relay neurone
Motor neurone
Effector
Response

Question 23

Give the steps in the reflex arc in more detail

Answer 23

1) skin detects a stimulus
2)sensory neurones send electrical impulses to relay neurones- located in the spinal chord. They connect sensory neurones to motor neurones
3) motor neurones send electrical impulses to an effector
4) the effector produces a response

Question 24

Give the aim of the practical to investigate human reaction time

Answer 24

To determine whether a factor such as caffeine or background noises affects reaction time

Question 25

What do sensory neurones do?

Answer 25

Transmit signals from receptors

Question 26

What do relay neurones do?

Answer 26

Transmit signals between neurones

Question 27

What do motor neurones do?

Answer 27

Transmit signals to effectors

Question 28

Give the sequence of events for a voluntary response

Answer 28

-Stimulated receptor— sensory neurones
-Sensory neurone send a signal to the spinal chord then to the brain
-The brain processes then sends a signal via a motor neurone to the effector
- effector carried out the response

Question 29

Give the sequence of an involuntary action (reflex)

Answer 29

-stimulated receptor send a signal to a sensory neurone
-the sensory neurone sends a signal to a relay neurone in the spinal chord
-relay neurone connects to a motor neurone
-Response travels from the motor neurone to the effector
-effector carries out the response