Sense Of Hearing

Question 1

Sense of hearing: the ear has two sensory functions hearing and balance ( equilibrium)

Answer 1

• sensory receptors for both functions are meachanoreceptores in the inner ear.
• meachanoreceptores contains of hair cells with stereocilia ( long microvillia) that are sensitive to mechanical stimulation.

Question 2

Anatomy of the ear has three divisions

The auditory tube extends to the nasopharynx, equalization of air pressure.

Answer 2

1- inner ear: the only part that is fluid- filled.
It has three main areas: semicircular canals for equilibrium/ vestibular for equilibrium/ cochlea for hearing.
2- middle ear begins at the tympanic membrane (eardrum) and ends at oval window
Three bones( malleus, incus, and stapes called ossicles).
3- outer ear: the pinna funnels sounds into the auditory canals.

Question 3

Auditory pathway to the brain

Answer 3

Auditory canal sounds leaves
Vibrates to the tympanic membrane
Vibration are amplified across the ossicles
Stapes strikes the oval window this oval transmits Vibration to the cochlea/ the organ of corti( the sense organ for hearing is founding inside the cochlea.
Corti move up and down which cause stereocilia to bend. Has different frequencies: at the tip to low pitched sounds, at the base to high pitched sounds.
The cochlea nerve send impulses to the auditory cortex in the temporal lobe.

Question 4

Volume is due to the amplitude ( height) of sounds waves.

Answer 4

Loud noises cause more intense Vibration, so the amplitude of sound waves is larger.
The brainterprets this as volume.