Special Senses- Ear Flashcards
(10 cards)
1
Q
What is the Ear ?
A
- organ of hearing
- stimulated by 8th cranial nerve
- consists of internal, middle and external ear
2
Q
What consists in the External Ear ?
A
- Auricle/ Pinna
2. External auditory meatus
3
Q
What is the Auricle/ Pinna
A
- composed of fibrous elastic cartilage covered by skin
- many sebaceous glands opening into hair follicles
- deeply grooved and ridged
4
Q
What is the External Auditory Meatus ?
A
- a tube from auricle to tympanic membrane
- consists of cartilaginous and osteosarcoma portions
- meatus about 2.5cm long, slightly S shaped
5
Q
What is the Cartilaginous Portion of the External Auditory Meatus ?
A
- modified sweat glands, ceremonious glands
- secretes crewmen/ wax
- wax is for protective functions
6
Q
What is the Middle Ear ?
A
- irregular shaped cavity that contains air
- auditory tube extends from nasal part of pharynx to middle ear
- both sides tympanic membrane has atmospheric pressure
- tympanic membrane(eardrum) vibrates when sound is heard
7
Q
What consists in the Middle Ear ?
A
- Tympanic Membrane (Eardrum)
2. Auditory Ossicles (Malleus, Incus, Stapes)
8
Q
What is the Malleus ?
A
- lateral aspect of the middle ear
- shaped like a hammer (w/t head, neck and handle)
- handle of Malleus in contact with medial wall of tympanic membrane
- head forms a movable joint with incus
9
Q
What is Incus ?
A
- intermediate bone of Auditory Ossicles
- shaped like anvil
- has a body and 2 processes
- body articulates with Malleus
10
Q
What is Stapes ?
A
- most medial of the Auditory Ossicles
- has head, neck, 2 limbs and base
- head articulates with incus, base fits into fenestra vestibule
- 3 ossicles are maintained in position by fine ligaments
