Sense organs Flashcards
1
Q
Sense organ
A
A group of receptor cells that respond to a specific stimulus
2
Q
sense organs in humans & their stimuli
A
eye - light ear - sound skin - touch, temperature nose - chemicals mouth - chemicals
3
Q
what direction does light entering the eye travel
A
cornea → pupil → lens → optic nerve
4
Q
Cornea
A
- Transparent outer layer
- Refracts light, focusing it towards the retina
5
Q
Pupil
A
the ‘hole’ at the front through which light can pass into the eye from the cornea to the lens
6
Q
Lens
A
- Transparent rounded structure
- Refracts light, focusing it onto the retina
7
Q
Iris
A
- The coloured part of the eye
- Controls the amount of light passing through the pupil
8
Q
Retina
A
- Layer containing receptor cells
- Responds to light levels and to light of different colours
9
Q
Optic nerve
A
- Bundle of neurones
- Carries nerve impulses from the retina to the brain
10
Q
Blind spot
A
the part of the retina where the optic nerve enters the eye
11
Q
Cones*
A
12
Q
rods *
A
13
Q
Reactions of the pupil to light intensity
A
- in dim light, the pupil becomes larger, letting more light into the eye
- in bright light, the pupil becomes smaller, letting less light into the eye
