2.5 The Brain & The Eye

Question 1

What is the brain made of?

Answer 1

The brain is made of billions of interconnected neurones

Question 2

What is the function of the brain?

Answer 2

The function of the brain is to control complex behaviour

Question 3

What are the 6 regions of the brain?

Answer 3

• Cerebral Cortex
• Cerebellum
• Medulla
• Spinal Chord
• Pituitary Gland
• Hypothalamus

Question 4

What is the Cerebral Cortex responsible for?

Answer 4

The Cerebral Cortex controls language, memory, intelligence and consciousness

Question 5

What is the Cerebellum responsible for?

Answer 5

The Cerebellum is responsible for muscle coordination, balance and movement

Question 6

What is the Medulla responsible for?

Answer 6

The Medulla is responsible for unconscious activities such as breathing and heart rate

Question 7

Why is difficult to investigate and study brain function?

Answer 7

Because the brain is an incredibly complex and very delicate organ

• Also because it is inside the skull

Question 8

How have neuroscientists been able to research and map out parts of the brain?

Answer 8

• By studying people with brain damage to see which functions have been affected
• By electrically stimulating parts of the brain to observe any visible responses and also see the effects of it
• By using MRI Scanning Techniques to help highlight areas of the brain that are active during different activities

Question 9

Explain the Eye

Answer 9

The eye is a sense organ which contains receptors that are sensitive to light intensity and colour

Question 10

What is the Iris?

Answer 10

The iris is a thin layer in front of the lens
It contains muscle cells which contract to control the size of the pupil

Question 11

What is the Pupil?

Answer 11

The pupil is a hole that allows light to enter the eye

Question 12

What are Ciliary Muscles?

Answer 12

Ciliary muscles are rings of muscles that change the shape of the lens to focus light rays on the back of the retina

Question 13

What are Suspensory Ligaments?

Answer 13

Suspensory Ligaments are strong radial ligaments that hold the lens in the centre of the right of the ciliary muscle

Question 14

What is the retina?

Answer 14

The retina is a layer containing receptors sensitive to the light intensity and light colour

Question 15

What are the two types of receptor cells in the eye?

What are they responsible for?

Answer 15

• Rod Cells which detect light intensity
• Cone Cells which detect colour

Question 16

What is the function of the optic nerve?

Answer 16

The optic nerve contains neurones that carry impulses from the receptor cells in the retina to the brain, and from the brain to the muscles in the eye

Question 17

What is the sclera?

Answer 17

The sclera is the white, protective outer layer of the eye that protects the eye and maintains the shape of the eye

Question 18

What is the cornea?

Answer 18

The cornea is a transparent part of the sclera which allows light through eye and refracts it as it enters the eye to focus on the retina

Question 19

What is the function of the lens?

Answer 19

The lens refracts rays of light so that they focus at the retina

Question 20

What features allow the lens to perform its function?

Answer 20

The lens is elastic, so it is able to change shape when the suspensory ligaments attached to it become tighter or looser.

Question 21

What is accommodation?

Answer 21

Accommodation is the process of changing the shape of the lens so that they focus on near or distant objects

Question 22

How does the eye focus on a near object?

Answer 22

The ciliary muscles contract whilst the suspensory ligaments loosen, causing the lens to be thicker and light to be refracted strongly

Question 23

How does the eye focus on a distant object?

Answer 23

The ciliary muscles relax whilst the suspensory muscles are pulled tight, causing the lens to be pulled thin and refract light lightly

Question 24

What is adaptation?

Answer 24

Adaptation is a reflex action that protects the retina from damage in bright light and protects us from not seeing objects in dim light

Question 25

What happens to the iris in bright light?

In terms of adaptation

Answer 25

In bright light, the circular muscles of the iris contract to narrow the size of the pupil - to prevent too much light from entering

Question 26

What happens to the iris in dim light?

Answer 26

In dim light, the radial muscles of the iris contract to dilate the pupils and allow as much light as possible into the eye

Question 27

What are the 2 defects of the eyes?

+ How do they happen?

Answer 27

Myopia (Short-Sightedness)
Hyperopia (Long-sightedness)

They happen when the rays of light do not focus on the retina

Question 28

How are myopia and hyperopia generally treated?

Answer 28

Myopia and Hyperopia are generally treated with spectacle lenses that refract rays of light so that they focus on the retina

• Myopia is generally treated with concave lenses
• Hyperopia is generally treated with convex lenses

Question 29

What type of new technologies can also treat eye defects?

Answer 29

• Soft and hard contact lenses
• Laser surgery that changes the shape of the cornea
• A replacement lens in the eye