The senses Flashcards
what does the Ears do
Ears provide hearing and maintain body balance
Ear structure has 3 parts
- Outer ear
- Middle ear
- Inner ear
The outer ear functions
- The visible part of the ear
- Protects the inner structures from damage
- The passage for sound waves
functions of External auditory meatus - the
auditory canal
- Lined with ceruminous glands and hairs
- Filter out dust and foreign particles
functions of The tympanic membrane
(eardrum)
separates the auditory canal from the middle ear
The middle ear
1-Found within a cavity in the temporal bone
2-Has minute bones known as auditory ossicles
3-Auditory ossicles transmit sounds from
the tympanic membrane to the inner ear
The inner ear structure
1- ampulla
2- oval window
3- round window
The inner ear functions
- Responsible for hearing and balance
- Within the inner ear structures the vibrations of sound waves are translated into nerve impulses
- Semi-circular canals and vestibule help to maintain posture and balance
function of The eustachian tube
Connects the middle ear to the throat Maintains the atmospheric pressure of air within the ear Enables eardrum to vibrate as the soundwaves reach it
how does the inner ear work
The cochlea receives sound in the form of vibrations
* Vibrations cause the stereocilia to move.
* Stereocilia then convert these vibrations into nerve impulses which are taken up to the brain to be interpreted.
Eye structures
Eyelids
* Layers of tissue above and below the
front of the eye
* Protect the eyes through blinking
Eyelashes
* Line the edges of the eyelids
* Filter and trap substances e.g. dust
Sebaceous and mucous secretions
lubricate the eyelids
Lacrimal glands
secretes what
lacrimal fluid
what is lacrimal fluid function
- keeps the surface of the
eye moist - Prevents the cornea from
drying out
Parasympathetic stimulation of the lacrimal
glands causes
crying
what is The sclera
- A fibrous outer layer
- At the front of the eye it is continuous with the cornea
