The senses Flashcards
Conjunctiva
Protects sclera
Sclera
Holds in eye in shape
Cornea
Let’s light into eye
Choroid
Absorbs light in the eye
Retina
Light acceptors
Cons and rods
Cons
6 million in eye
Detect colours
Work in bright light
Mostly @fovea
Rods
120 million in eye
Detects black and white
Works in dim light
All over retina
Fovea
Region is sharpest vision
Images are focused
Blind spot
No rods/cones
Not sensitive to light
Optic nerve
Carries impulses to brain
Cerebum
Lens
Changes shape to focus light on retina
Ciliary muscle
Causes lens to change depending on what looking at
Accommodation
Changing of the lends depending on what one is focusing on
Iris
Controls Amount of light entering the eye
Aqueous humour
Salt solution holds front eye in place
Vitreous humour
Supports eye by exerting outward pressure
External muscle
Moves the eye
Long sighted
Convex
Short sighted
Concave
Ear
Balance and hearing
Pinna
Collects and channels vibrations into auditory canal
Auditory canal
Carries vibrations to ear drum
Eardrum
Vibrates as result of vibrations that reach it
Ossicles
Three tiny bones hammer anvil stirrup
Transmit and amplify vibrations
Eustachian tube
Equalises pressure on either side of eardrum
Middle ear to pharynx(throat)
Cochlea
Responsible for hearing
Converts vibrations into electrical impulses
Organ of corti
In cochlea
contains receptor cells that allow hearing
Semilunar canals
Responsible for balance
Filled with lymph
Balance
Detected by vestibular apparatus in inner ear
Pain parts of apparatus in semilunar canal
Deafness
Cause:loud noises over a long period of time
Treatment: hearing aids
