Nerves And Sensitivity

Question 1

What is a coordinated response?

Answer 1

Being able to make things happen in different parts of the body and at the right time

Question 2

Which two systems do animals use to coordinate responses?

Answer 2

The nervous system The endocrine (hormone) system

Question 3

A coordinated response requires 3 things….

Answer 3

Stimulus Receptor Effector

Question 4

What is a stimulus?

Answer 4

Change in animals surroundings

Question 5

What is a receptor?

Answer 5

Organ that detects the change e.g. Your eye

Question 6

What is the effector?

Answer 6

Muscles are the effectors that respond and make something happen

Question 7

What energy change takes place in the eye receptor?

Answer 7

Light into electrical nerve impulses

Question 8

What energy change takes place in the ear receptor?

Answer 8

Sound into electrical nerve impulses

Question 9

What energy changes take place in the tongue receptor?

Answer 9

Chemical to electrical nerve impulses

Question 10

What energy change takes place in the nose receptor?

Answer 10

Chemical to electrical nerve impulses

Question 11

What energy changes take place in the touch receptors in skin?

Answer 11

Pressure into electrical nerve impulses

Question 12

What energy changes take place in the temperature receptors in skin?

Answer 12

Heat into electrical nerve impulses

Question 13

Name the 2 main parts of the central nervous system

Answer 13

Brain and spinal cord

Question 14

Which part of the nervous system contains all other nerves which send impulses to all effectors (muscles)

Answer 14

Peripheral nervous system

Question 15

What does the central nervous system do?

Answer 15

Coordinates all nervous responses such as moving or reflexes

Question 16

Name the 3 types of neurone.

Answer 16

Sensory neurones - from receptors Relay neurones - to central nervous system Motor neurones - to the effectors (muscles)

Question 17

Name the parts of a motor neurone

Answer 17

• Nucleus
• Dendrite
• Cell body
• Axon
• Myelin sheath

Question 18

What does the myelin sheath do?

Answer 18

Insulates the axon and speeds up the transmission of the impulse.

Question 19

What does the dendrite do?

Answer 19

Tree like projections which connect to many different neurones

Question 20

What is a reflex?

Answer 20

Automatic actions which do not involve the brain They are very fast and involve the three neurones Impulse moves from receptor to effector in a reflex arc

Question 21

Describe how a reflex arc response works. Clue: touching a hot plate

Answer 21

1. Receptor detects stimulus
2. Sends impulse along a sensory neurone
3. Sensory neurone passes impulse across the spinal cord to the relay neurone
4. Relay neurone passes the impulse to the motor neurone
5. Motor neurone causes the effector to contract
6. Gap between neurones is called a synapse

Question 22

What is a synapse

Answer 22

A junction between two nerve cells