(final prep) special senses

Question 1

ear is divided into 3 parts

Answer 1

1. external ear
2. middle ear
3. internal ear

Question 2

external ear

Answer 2

collects sound waves and focuses them inward

consists of: pinna (auricle), external auditory canal, leading to the eardrum/tympanic membrane

Question 3

middle ear

Answer 3

loc: in temporal bone

small air filled cavity, lined w. epithelium

most outer (lateral) wall: eardrum (tympanic membrane)

most inner (medial) border: thin bony plate w. 2 openings 1. oval and 2. round windows.

also houses the auditory ossicles connected via synovial joints: MALEUS (hammer), INCUS (anvil), STAPES (stirrup)
* the handle of the hammer is attached to the eardrum

the middle ear communicates with the nasopharynx by means of Eustachian tube

Question 4

inner ear (labyrinth)

Answer 4

canal /net like structure consists of
BONY outer labyrinth (lined with periosteum)
and MEMBRANOUS inner labyrinth (flowing w. enodolymph)
*bet. these two is perilymph fluid

divided into 3 portions:

1. semicircular canals
2. vestibule - receptors for equilibrium (utricle and sacculi filled with endolymph)
3. chochlea - receptors for hearing

Question 5

static movement (straightline) is detected by

Answer 5

structures of the vestibule
macula utriculi - detects horizontal movement
macula sacculi - detects vertical movement

Question 6

kinetic movement (rotational movement of head)

Answer 6

is detected by hair cells in christa ampullaris in ampulae of semicircular canals

Question 7

3 semicircular canals

Answer 7

2 vertically oriented (anterior and posterior)
1 horizontally oriented (lateral)

*ea. canal has a broad portion ampulla