Ear Flashcards
What are the three main areas of the ear?
Outer ear
Middle ear
Inner ear
What are the main structures of the outer ear? x3
Auricle (pinna)
Ear canal (external auditory meatus)
Tympanic membrane (eardrum)
What is the function of the auricle?
Outer ear - most visible part
Acts as a funnel
Helps localise sound
Conchae - resonating cavity
What is the function of the ear canal?
Concha to the ear drum
Transmits sound from pinna to eardrum
What is the function of the ear drum?
Located at the end of the auditory canal
Three layered tissue
Vibrates in response to pressure from sound waves
Easily damaged
What are the main structures of the middle ear?
- Ossicular chain (malleus, incus, stapes)
- Eustachian tube
- Oval and round windows
What is the function of the ossicular chain? x2
Bones of the middle ear
1. Transmits sound efficiently with no distortion
2. Amplifies incoming sound before transmitting it into inner ear fluid
What is the function of the eustachian tube?
Connects middle ear to nasopharynx
1. Aeration - brings O2 to the middle ear
2. Maintains air pressure within and outside the middle ear
3. Can allow infections to spread to the middle ear
What are the main structures of the inner ear? x2
- Balance sensors (vestibular system)
- Hearing sensors (cochlea)
What is the function of the cochlea?
Small fluid filled spiral in the temporal bone
1. Sound waves are transmitted from the oval window to the cochlea fluid
2. Basilar membrane - tissue within the cochlea containing hair cells (cilia) turn movement into electrical sound
3. Electrical signal travels along the auditory nerve to the brain where the messages are interpreted as recognised sounds
What is the function of the vestibular system?
Semicircular canals - part of the vestibular system
Three fluid filled tubes
Contains hair cells that detect movement in the fluid - sends impulses to the brain
Brain decodes this and helps body keep balance
