The Senses - Chp 34

Skin Diagram

What does the skin sense?

• temperature

• touch

What does the tongue sense?

• taste buds/sensors sense taste

  • the more we eat of a certain food the more taste buds we develeop

What neurons in the nose detect smell?

• olfactory neurons found in the back of the nose

Eye Diagram

Name + give the function of the parts of the eye:

conjunctiva - protective membrane around the eye

sclera - tough white layer around the eye that keeps its shape

retina - light sensitive area at the back of the eye containing rods and cones

cornea - front part of the sclera that allows light in and focuses it onto the retina

fovea - part of the retina where most images are focused

blind spot - where the optic nerve leaves the retina

optic nerve carries impulses to the brain

lens - focuses light onto the retina

iris - muscle that changes the size of the pupil controlling the amount of light let in

pupil - a hole at the front of the eye that lets light into it

cilliary muscles - change the shape of the lens

aqueous + vitreous humour - keep the eye in shape + absorbs shock

What is the difference between rods and cones?

Rods

• see in black and white

• more

• work in dim light

• many all over the retina

Cones

• see in colour

• fewer

• work in bright light

• focused around the fovea

Ear Diagram

Name + give the function of the parts of the ear:

pinna - the outer part of the ear that collect vibrations

auditory canal - carries vibrations to the eardrum

eardrum - carries the vibrations to the middle ear, physical barrier prevents water entering ear

ossicles - consist of the hammer, anvil and stirrup, they amplify the vibrations and pass them onto the oval window

cochlea - converts the vibrations into electrical impulses that are sent to the brain along the auditory nerve

eustachian tube - connects the middle ear with the pharynx and helps to equalise pressure between the middle and outer ear

Name + describe + give a correction for a hearing disorder

• glue ear

• a sticky substance builds up in the inner ear causing some deafness

  • decongestions can be given or a small operation to place tubes called grommets to keep it open

How does the ear control balance?

• the vestibular apparatus in the inner ear controls balance

• it consists of 3 semisicircular tubes filled with fluid that moves as we move

• if the tubes are blocked by infection the fluid cant move causing us to lose our balance