B1 - The nervous system

Question 1

What is monocular vision?

Answer 1

Monocular vision is where each eye is used separately.

Question 2

What is binocular vision?

Answer 2

Binocular vision is where both eyes are used together.

Question 3

What are the advantages to monocular vision?

Answer 3

The main advantage to monocular vision is that you are capable of having a wider field of view.

Question 4

What are the disadvantages to monocular vision?

Answer 4

The eyes are not very good at judging distance.

Question 5

What are the advantages to binocular vision?

Answer 5

The eyes are good at judging distance.

Question 6

What are the disadvantages to binocular vision?

Answer 6

You do not have a wide field of view.

Question 7

What are the different sense organs?

Answer 7

• ears
• nose
• tongue
• eyes
• skin

Question 8

Which sense organ reacts to a change in temperature?

Answer 8

The skin detects pressure, temperature and pain.

Question 9

How does binocular vision work?

Answer 9

Binocular vision produces two images and the brain compares the two images. The more similar they are, the further away is the object they are looking at.

Question 10

What does the cornea do?

Answer 10

Refracts light - bends it as it enters the eye.

Question 11

What does the iris do?

Answer 11

Controls how much light enters the pupil.

Question 12

What does the lens do?

Answer 12

Focuses light onto the retina.

Question 13

What does the retina do?

Answer 13

Contains the light receptors.

Question 14

What does the optic nerve do?

Answer 14

Carries impulses from the eye to the brain.

Question 15

What do ciliary muscles and suspensory ligaments do?

Answer 15

They work together to alter the shape of the lens.

Question 16

What causes red-green colour blindness?

Answer 16

Red-green colour blindness is an inherited condition where people do not have specialised cells in the retina.

Question 17

How is short sight corrected?

Answer 17

Diverging lens bends the light rays outwards before they enter the eye.

Question 18

How is long sight corrected?

Answer 18

Converging lens bend light rays inwards before they enter the eye.

Question 19

What is a reflex?

Answer 19

A muscular action that we take without thinking.

Question 20

Why do reflex actions protect us?

Answer 20

They are fast and automatic.

Question 21

What is the central nervous system made up of?

Answer 21

The brain and the spinal cord.

Question 22

What is the peripheral nervous system made up of?

Answer 22

Nerves to and from the brain and spinal cord.

Question 23

What do neurons carry?

Answer 23

Neurons carry nerve impulses.

Question 24

What do sensory neurons do?

Answer 24

Sensory neurons carry impulses away from sensory receptors.

Question 25

What do motor neurons do?

Answer 25

Motor neurons carry impulses to an effector.

Question 26

What are the different parts of a motor neuron?

Answer 26

• axon
• sheath
• nucleus
• cell body
• dendrites

Question 27

How are neurons adapted to carry and pass on nerve impulses quickly?

Answer 27

Neurons:

• are long
• have branched endings to pick up impulses
• are insulated by a fatty sheath to prevent loss of impulse

Question 28

What is a synapse?

Answer 28

A junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter