The Ear + The skin Flashcards
2 functions of the ear
hearing
balance
3 parts of a mammalian ear
air-filled outer ear
air-filled middle ear
fluid-filled inner ear
3 parts of the outer ear
pinna
external auditory canal
eardrum
pinna is composed of
cartilage
function of pinna
helps to collect and funnel sound waves into the ear
external auditory canal
lined with hairs and wax-producing cells
function of external auditory canal
wax traps dirt, microbed etc, and protects ear
eardrum
a tightly stretched membrane that separates the outer ear from the middle ear
function of eardrum
transfers sound waves to the middle ear
middle ear contains
3 bones called the malleus, the incus and the stapes (hammer, anvil and stirrup)
function of the bones
carry sound waves from the eardrum to the oval window
function of oval window
transfers sound waves to the inner ear
eustachian tube
connects middle ear with the pharynx
function of eustachian tube
keeps air pressure equal on both sides of the eardrum
inner ear
a coiled tube filled with fluid (lymph)
contains sensory cells
inner ear consists of
the cochlea
the semi-circular canals, utricle and saccule
function of the cochlea
hearing - converts sound waves into nerve impulses
function of the semi-circular canals, utricle and saccule
balance - they detect movement, acceleration and position of head in relation to gravity
sound is caused by
vibrations in the air
first thing that happens to the sound
vibrations pass through the outer ear and ear drum to the middle ear
when sound waves are in middle ear
they pass via the ear bones and oval window the the fluid in the cochlea
when sound has reached cochlea
movement in the fluid of cochlea stimulates sensory hair cells
sensory cells send electrical impulses to the brain via the auditory nerve
brain interprets these as sound