Nerves

Question 1

What is a stimulus?

Answer 1

A change in your environment which you may need to react to

Question 2

What are your 5 different sense organs?

Answer 2

Eyes, ears, nose, tongue and skin

Question 3

What are receptors?

Answer 3

Groups off cells which are sensitive to stimuli

Question 4

What do receptors do?

Answer 4

They change stimulus energy into electrical impulses

Question 5

What does the CNS consist of ?

Answer 5

Brain + spinal cord

Question 6

What happens in the CNS?

Answer 6

The information from sense organs is sent there and responses are coordinated

Question 7

What are sensory neurones?

Answer 7

The nerve cells that carry signals as electrical impulses from the receptors in the sense organs to the CNS

Question 8

What are relay neurones?

Answer 8

The nerve cells that carry signals from sensory neurones to motor neurones

Question 9

What are motor neurones?

Answer 9

The nerve cells that carry signals from the CNS to the effector

Question 10

What are effectors?

Answer 10

Muscles and glands

Question 11

How do muscles and glands react differently to nervous impulses?

Answer 11

Muscles contract, glands secrete chemicals

Question 12

What is synapse?

Answer 12

The connection between 2 neurones

Question 13

How is the nerve signal transferred?

Answer 13

By chemicals which diffuse across the gap

Question 14

What are reflexes?

Answer 14

Automatic, rapid responses to certain stimuli

Question 15

Describe what happens when a bee stings your finger?

Answer 15

• when a stimulus is detected by receptors, impulses are sent along a sensory neurone to the CNS
• when the impulses reach a synapse between the sensory and relay neurone, they trigger chemicals to be released. These chemicals cause impulses to be sent along the relay neurone
• the same thing happens when the impulses reach the synapse between relay neurone and motor neurone
• the impulses then travel along the motor neurone to the effector
• the muscle then contracts moving your hand away from the bee

Question 16

Describe the pathway a behaviour takes?

Answer 16

• stimulus
• receptor
• sensory neurone
• brain
• motor neurone
• effector
• response

Question 17

What are the 3 areas of the brain?

Answer 17

Cerebral cortex, cerebellum , medulla

Question 18

What is the cerebral cortex and what does it do?

Answer 18

It is the outer wrinkly bit. It’s responsible for consciousness, memory, intelligence and language

Question 19

What does the cerebellum do?

Answer 19

It is responsible for muscle coordination

Question 20

What does the medulla do?

Answer 20

It control unconscious activities like breathing and your heart rate

Question 21

What are the 3 methods scientists use to study the brain?

Answer 21

• Studying patients with brain damage
• Electrically stimulating the brain
• MRI scans

Question 22

Describe how scientist study patients with brain damage

Answer 22

If a small part of the brain has been damaged the effect this has on the patient can tell you a lot about what the damaged part of the brain does.

Question 23

Describe how scientists electrically stimulate the brain

Answer 23

The brain can be electrically stimulated by pushing a tiny electrode into the tissue and giving it a small zap of electricity. By stimulating what different parts of the brain does, it is possible to get and idea of what those part do.

Question 24

How do MRI scans help to study the brain?

Answer 24

An MRI scanner is a big tube-like machine that can produce a very detailed picture of the brain’s structures. Scientists use it to found out what parts of the brain are active when people are listening to music or trying to recall memory