The Ear - External, Middle, & Inner

The Ear

receptor organ for hearing & equilibrium (balance) 

What are three main regions of the ear?

External, Middle, & Internal Ear

What is the functions of External & Middle Ear?

Hearing

What is the function of Internal Ear?

Both Hearing & Equilibrium

External Ear is composed of…

Auricle (pinna)

Auricle (pinna) 

helps direct sounds 

What does the External Acoustic Meatus contain?

Hairs, Sebaceous glands & ceruminous glands

External Ear - Tympanic membrane

forms the boundary between the external & the middle ear (Ear drum)

Middle Ear - Ear Ossicles

smallest bones in the body

Middle Ear - Malleus

attaches to the eardrum

Middle Ear - Incus

between malleus & stapes

What is the Middle Ear - Medial wall penetrated by?

Oval & Round Window

Middle Ear - Pharyngotympanic tube (Auditory tube) 

Links the middle ear & pharynx 

Inner Ear - Bony Labyrinth

a cavity consisting of: Semicircular Canals, Vestibule, & Cochlea

What is Cochlea filled with? 

Fluid & Hair Cells 

When you hear sound, the vibration of air in your outer ear cause….

the bones in the middle ear to shake/vibrate.

What happens vibration hits the ear?

It causes fluid in the cochlea to move, which moves hair cells in the Cochlea.

What does the moving hair cells in Cochlea trigger?

CN - VIII to send action potentials to the brain.

Semicircular Canals - Balance

Hair Cells (Ampullary Cupula) detect the movement of fluid & tells your brain about where you are in space.

Motion Sickness

mismatch in the movement of fluid in your semicircular canal and what your eyes see.