Eye and Ear

State two features that show how the lens are adapted for focusing light onto the retina

• can change shape in response to the contraction and relaxation of ciliary body

• Transparent

Name the two types of light receptor cells in the retina and give their function

Rods: vision in black and white

Cones: vision in red, green and blue

Why could damage to the optic nerve result in blindness

No message or impulse will be sent to the brain

Describe a corrective measure for long sightedness and short sightedness

Long sightedness: Convex lens

Short sightedness: Concave lens

Vision and hearing are two of five senses in humans. Name one of the other sense and the organ associated with this sense

Taste - Tongue

What is the function of the optic nerve

carries message from the eye to the brain

What is the function of the iris

Contracts and relaxes in response to the amount of light entering the eye

Name and explain the function of each of the following:

1. fluid that fills the rear chamber

2. The two types of light receptor cells

3. the transparent covering in front of the cornea

1. Vitreous humour: maintains the shape of the eye

2. Rods and cones: Rods function in vision of black and white, and cones function in visions of red, green and blue

3. Lens: Focuses light onto the retina

Name a part of the eye that has a corresponding feature to the cochlea in the ear and explain why

Retina. Both contain receptors and detect stimuli

Name a structure that determines the diameter of the pupil

Iris

Why is there a mechanism for changing the diameter of the pupil

To control the amount of light entering the eye

Name two parts of the eye that are curved and transparent

• Lens

• Cornea

How does the curvature contribute to the eye’s function

To refract light

The eyes of carnivores are located relatively close together at the front of the skull.

The eyes of herbivores tend to be located at the sides of the skull.

With reference to either herbivores or carnivores, suggest the benefits of either arrangement

Herbivore: Wider field vision/ detection of predators

Carnivore: Better judgement of distance/ Better focus on prey

Give function of Semi-circular canals and Cochlea

Semi-circular canals - Balance

Cochlea - Hearing

What’s name given to the bone that protects the internal part of the ear

Skull

The eardrum transfers sound vibrations to three small bones. What is the collective term for these three bones?

Ossicles

The Eustachian tube connects the middle ear to another structure. What is this structure?

Throat

Name one disorder of the ear and a treatment

Disorder: Glue ear

Treatment: Grommets

What is the function of the Eustachian tube?

Equalises pressure

What is the function of the semi-circular canals?

Balance

Briefly outline the function of the pinna

picks up sound waves and channels them to the eardrum

Name another part of the ear that has a similar function to the stirrup

Anvil

Function of the ossicles

Transfer sound waves into the inner ear