Ear Flashcards
illustrate a large diagram of the internal structure of the ear
see diagram in manual
what does the middle ear consist of
ear ossicles, oval window, round window and eustachian tube
what does the outer ear consist of
pinna, auditory canal and eardrum
what does the inner ear consist of
cochlea and semi circular canals
suggest one way by which the ear may be protected
- by the skull
- wax
- wearing ear protection
choose any one or can just learn all off
structure and function of the pinna
- the pinna is skin converted cartilage
- it’s role is to collect sound waves and direct them to the auditory canal
structure and function of the auditory canal
- the auditory canal is a short curved tube extending from the pinna to the eardrum. secretes ear wax for protection
- it’s role is to carry sound waves to the eardrum. The ear wax keeps canals clean and so protects the ear
structure and function of the eardrum
- the eardrum is a tightly stretched membrane which separates the outer ear from the middle ear
- it’s role is to vibrate same frequency as sound waves reaching it and transfers these vibrations to the ear ossicles of the middle ear
structure and function of the ear ossicles
- the ear ossicles are three tiny bones which connect the ear drum to the oval window
- it’s role is to transfer and amplify vibrations of the eardrum to the oval window
structure and function of the oval window
- the oval window separates the air filled middle ear from the liquid filled inner ear
- it’s role is to transfer vibrations of the stirrup to the cochlea ** this sets up pressure waves in the cochlea
structure and function of the eustachian tube
- this tube is connected to the pharynx and is normally closed. it’s opened we swallow and yawn
- it’s role is to equalise air pressure on either side of the ear drum
function of the round window
-it’s role is to dampen the pressure changes in the cochlea so that one can hear many sounds clearly in quick succession
Structure and function of the cochlea
- the cochlea is a spiral bony chamber filled with lymph
- it’s role is to generate nerve impulses from pressure waves
a. Contains sound receptors which are stimulated by the movement of lymph
b. Receptors generate an impulse which is sent to the brain through the auditory nerve
c. The brain interprets impulse as sound
Role of semi circular canals
-balance is controlled by the vestibular apparatus it consists of the semicircular canals nerve impulses are generated inside these semicircular canals
why are there three semicircular canals
to control balance in three planes
What is the role of the cochlea
Generates impulses
Describe the mechanisms of hearing
- Vibrations are collected in the outer ear
- These vibrations pass through the middle ear and are amplified by the ear ossicles
- Vibrations reach the cochlea and create pressure waves in the lymph of the cochlea
- Receptors in the cochlea are stimulated and these then create impulses
- The auditory nerve tranmits impulses to the brain
- The brain interprets impulse as sound
- The round window allows pressure waves to leave the cochlea and pass into the air filled middle ear
Name a disorder associated with the ear along with the description and corrective measure
Disorder : glue ear
Description: inflammation of the middle ear
-results from bacterial infection
Corrective measure: antibiotics
