Senses

Question 1

Sensitivity

Answer 1

Ability to detect and respond to stimuli

Question 2

Stimuli

Answer 2

Changes in the environment that causes a response

Question 3

Process of getting signals

Answer 3

Stimulus
detected by
Specialised sensory cells in a sense organ
send signals through nerves to
Brin
produces
Sense

Question 4

Eye ear nose tongue skin

Answer 4

Eye&raquo_space; light&raquo_space; sight
Ear&raquo_space; sound&raquo_space; hearing
Nose&raquo_space; smells of chemical substances&raquo_space; smell
Tongue&raquo_space; flavours of chemical substances&raquo_space; taste
Skin&raquo_space; touch pressure pain temp&raquo_space; touch

Question 5

Eyelash

Answer 5

Prevent small particles from getting into eyes

Question 6

Eyebrow

Answer 6

Prevent sweat from getting into our eyes

Question 7

Eyelid

Answer 7

Close to protect eyes from dirt and strong light
Blink to moisten eye surface

Question 8

Cornea

Answer 8

Lets light pass through
Focuses light

Question 9

Iris

Answer 9

Control the size of pupil

Question 10

Pupil

Answer 10

Regulate amount of light entering eye

Question 11

Focusing muscle

Answer 11

Change thickness of lens

Question 12

Lens

Answer 12

Let light pass through
Focus light

Question 13

Jelly-like fluid

Answer 13

Maintain shape of eyeball
Help focus light

Question 14

Retina

Answer 14

Contains light-sensitive cells that detect light and produce signals

Question 15

Blind-spot

Answer 15

Spot where optic nerves leave eyeball
No light light-sensitive cells

Question 16

Optic nerve

Answer 16

Transmit signals from light-sensitive cells to brain

Question 17

Sclera

Answer 17

Protect eyeball
Maintain shape of eyeball

Question 18

Process of light into our eyes

Answer 18

1. Light from object enters our eyes through cornea
2. Cornea, lens and jelly0like fluid help focus light on retina
3. Sharp inverted image is formed on retina. Light-sensetive cells are stimulated by light to produce signals.
4. Signals sent to brain through optic nerves. Brain interprets signals as upright images.

Question 19

Humans have binocular vision…

Answer 19

…allows perception of depth

Question 20

Looking at near objects

Answer 20

Focusing muscles contract
Lens become thicker
Near object can focus on retina

Question 21

Distant object

Answer 21

Focusing muscles relax
Lens become thinner
Distant object can focus on retina

Question 22

Cells sensitive to bright light

Answer 22

Cone cells (RGB)

Question 23

Cells sensitive to dim light

Answer 23

Rod cells, no colour

Question 24

Why difficult to see in dark?

Answer 24

Only rod cells are stimulated and send signals to the brain

Question 25

Optical instruments defintion?

Answer 25

To extend our vision

Question 26

Optical instruments examples

Answer 26

Binoculars, hand lens, light microscope, electron microscope, astronomical telescope

Question 27

Why can't see stuff at blind spot

Answer 27

No light sensitive cells on blind spot When image is formed, no signals sent to brain, hence no sight.

Question 28

Possible causes of short-sightedness

Answer 28

Lens too thick Eyeballs too long

Question 29

Possible causes of long sightedness

Answer 29

Lens too thin Eyeball too short

Question 30

Astigmatism phenomenon and effect and fixed

Answer 30

Cornea or lens unevenly curved Light from object cannot form sharp image on retina Fixed: lenses with different curvatures at different points.

Question 31

Cataract phenomenon, effect and fixed

Answer 31

Lens become cloudy Light cannot pass through to reach retina, blurred vision Artificial lens through surgery

Question 32

Cataract causes

Answer 32

Old age. Heredity. Eye injuries. Prolonged exposure to sunlight.

Question 33

Colour-blindedness phenomenon, effect and (fixed)

Answer 33

Defect in 1 or more type of cone cells Affect distinguishing colours x

Question 34

Colour-blindness cause

Answer 34

Inherited, male>female