Unit Three: Equilibrium and Hearing Flashcards
What are the three anatomical regions of the ear?
- External ear. 2. Middle ear. 3. Internal ear.
What anatomical region of the ear contains the sensory organs for equilibrium (balance) and hearing?
The internal ear.
What does the external ear include? (2)
- The outer fleshy auricle. 2. External acoustic meatus.
What does the auricle protect? What does it provide?
The opening passageway and provides directional sensitivity to the ear by directing sound inward toward the tympanic membrane.
What is the tympanic membrane? What does it separate?
The eardrum. It is thin, semitransparent connective tissue separating the external ear from the middle ear.
What do ceruminous glands secrete?
Cerumen.
What does cerumen do?
Slows the growth of microorganisms and reduces the chance of infection.
What are ceruminous glands modifications of?
Sweat glands.
What does the middle ear consist of?
The tympanic cavity, which contains auditory ossicles.
What is the tympanic cavity?
An air-filled space that contains auditory ossicles.
What does the tympanic cavity communicate with? (2)
The nasopharaynx through the auditory canal. 2. Mastoid air cells.
Where does the auditory tube penetrate?
The petrous part of the temporal bone.
What is the auditory tube also called?
Eustachian tube.
What does the auditory tube do?
It helps equalize the pressure in the middle ear with external, atmospheric pressure.
What do the three bones comprising the auditory ossicles do?
They connect the tympanic membrane with the receptor complex of the internal ear.
What are the three auditory ossicles connected by? What do they do?
Synovial joints. They transfer sound vibrations from the tympanic membrane to a fluid-filled chamber within the internal ear.
What are the three auditory ossicles?
- Malleus. 2. Incus. 3. Stapes.
What is the oval window?
A hole in the bony wall of the middle ear cavity.
What does vibration of the tympanic membrane do?
It converts arriving sound waves into mechanical movements.
Describe the vibration of the auditory ossicles.
The malleus vibrates the incus. The incus vibrates the stapes.
What does the movement of the stapes do?
It causes vibrations in the fluid contents of the internal ear.
What is the auricle of the external ear made up of?
Elastic cartilage.
What two muscles reduce movements of the auditory ossicles in the ear?
- Tensor tympani muscle. 2. Stapedius muscle.