Special Senses II Flashcards
1
Q
the ear
A
- detects sound and movement of head
- signals transmitted via vestibulocochlear nerve (CN VIII)
- external, middle, and inner
2
Q
external ear
A
- auricle
- external acoustics meatus
- tympanic membrane
3
Q
auricle
A
- pinna
- funnel shapes visible part
- skin covered, elastic cartilage supported structure
- protects entry into ear and directs sounds waves in
4
Q
external acoustic meatus
A
- bony tube extending through temporal bone
5
Q
tympanic membrane
A
- eardrum
- delicate funnel shaped epithelial sheet
- separates external and middle
- termination of external acoustic meatus
- vibrates when sound waves hit it
- transmits sound wave energy into middle and inner ear
6
Q
protection of ear canal
A
- cerumen, wax like secretion of ceremonious glands
- combines with dead sloughed cells to form earwax
- prevents larges objects from entering
- fine hairs guarding opening
- may helps impede growth of microorganisms
7
Q
middle ear components
A
- auditory tube
- auditory ossicles
- auditory muscles
8
Q
middle ear
A
- in petrous (hard) part of temporal bone
- has air filled tympanic cavity
- sound transmitted here via auditory ossicles
- bound medially by bony wall
- houses oval and round window
- separates middle form inner ear
9
Q
oval and round window
A
- oval window= sound enters
- round window= sends sound back out
10
Q
auditory tube
A
- eustachian tube
- passage from middle ear to nasopharynx
- normally closed at connection to nasopharynx
- allows pressure to equalize in middle ear
11
Q
valsalva maneuver
A
- piping your ears
- pushes air in nasopharynx up tube to open it and equalize the pressure in middle ear
12
Q
3 auditory ossicles
A
3 smallest bones of body
1) malleus
2) incus
3) stapes
13
Q
malleus
A
- attached to medial surface of tympanic membrane
- resembles hammer
14
Q
incus
A
- middle ossicle resembling and anvil
15
Q
stapes
A
- resembles stirrup
- has disc-like footplate fitting into oval window
- beats on oval window where cochlea receives info
- marks lateral wall of inner ear
16
Q
auditory ossicles
A
- amplify and transmit sound waves into inner ear
- vibrate when sound waves strike tympanic membrane
- causes stapes footplate to move in and out of oval window
- movement initiating pressure waves in inner ear fluid
- tympanic membrane 20 time greater that footplate so sound transmitted amplified 20-fold
17
Q
pathway of sound in auditory ossicles
A
1) eardrum
2) malleus
3) incus
4) stapes
18
Q
auditory muscles
A
- stapedius (stapes) and tensor tympani (malleus)
- tiny skeletal muscles within middle ear
- restrict ossicles movement when loud noises occur
- bone could be moved out of place
19
Q
inner ear
A
- cochlea
- spiral organ