The senses

Question 1

All sense organs contain what ?

Answer 1

Receptor cells

Question 2

A receptor

Answer 2

A cell that can detect a stimulus

Question 3

A stimulus

Answer 3

Any change in your environment

Question 4

Eyelids

Answer 4

Protects eye blinking squeezes tears over surface of the eye

Question 5

Conjunctiva

Answer 5

Transparent lining on inside of eye lids that also travel across the cornea to protect it

Question 6

Sclera

Answer 6

White of eye
Holds shape of eye

Question 7

Cornea

Answer 7

Transparent part of sclera
Bends light for it to focus on retina

Question 8

Choroid

Answer 8

Contains blood vessels
Brings food and oxygen to cells of eye

Question 9

Retina

Answer 9

Contains light receptor cells
Two types -
rod for black and white -cone for coloured

Question 10

Blind spot

Answer 10

Part where the optic nerve leaves the eye
No rods or cones in this area

Question 11

Optic nerve

Answer 11

Carries impulse from eye to brain

Question 12

Iris

Answer 12

in dim light iris expands and allows more light in
In bright light the iris contracts and reduces light into eye

Question 13

Ciliary body

Answer 13

Thickened edge of choroid
Has muscle fibres that control the shape of the lens by pulling on the ligaments that hold it in place

Question 14

Fovea

Answer 14

Point of most accurate vision

Question 15

Aqueous humour

Answer 15

Water liquid at front of eye
supplies nurients to cornea and lens
helps maintain shape of the eye
helps refract light

Question 16

Vitreous humour

Answer 16

Protein gel behind the lens
helps hold shape of eye
help in refracting light onto the retina

Question 17

Acomodation

Answer 17

Is the ability of the lens to change its shape to form a clear image
(lens changes to convex for close objects)
(lens changes to concave for further objects)

Question 18

Pinna

Answer 18

Sticks out of from side of head
funnels sound into ear

Question 19

Eardrum

Answer 19

membrane of skin and fine protein fibres stretched across the inner part of our ear canal
vibrates when sound waves hit it

Question 20

3 small bones

Answer 20

Hammer, Anvil, Stirrup
amplify sound

Question 21

Eustachian tube

Answer 21

connects back of throat and ear

Question 22

Why should air pressure in and outside the eardrum be equal ?

Answer 22

so that the eardrum is free to vibrate

Question 23

What happens if air pressure outside eardrum drops ?

Answer 23

eardrum is stretched outwards and cannot vibrate

Question 24

How do our ears pop?

Answer 24

Eustachian tube opens

Question 25

How do we hear?

Answer 25

sound travels to eardrum through pinna
eardrum vibrates
hammer anvil and stirrup vibrate this amplifies sound
stirrup pushes on oval window of cochlea
liquid is moved by oval
hairs on receptor cells detect movement and send a signal to brain along the auditory nerve
brain interprets sound

Question 26

How does the ear balance?

Answer 26

The three semicircular canals are filled with fluid
head movement detected by nerves in these canals notifies brain
brain sends message to cerebellum which triggers reflex action in our muscles