Ear anatomy Flashcards
blood supply to external ear
- superficial temporal a.
2. posterior auricular a.
external ear inn.
posterior: spinal nn. (lesser occipital, great auricular
anterior: cranial nn. (auriculotemporal (V3), CN VII, CN X)
blood supply to tympanic membrane
- anterior tympanic a.
2. deep auricular a.
external surface of tympanic membrane inn.
GSA (ectoderm)
- auriculotemporal n. (V3)
- CN X
internal surface of tympanic membrane inn.
GVA (endoderm)
tympanic n. (CN IX)
embryonic origin of external accoustic meatus
1st pharyngeal cleft
embryonic origin of tympanic membrane
1st pharyngeal cleft + 1st pharyngeal pouch + mesoderm
embryonic origin of auricle
mesenchyme of 1st and 2nd arches
only muscle that opens auditory tube
tensor veli palatini, CN V
tensor tympani
dampens movement of ossicles, especially during chewing. CN V (2 “tens” or V)
stapedius
dampens movement of ossicles, CN VII
blood supply to middle ear
- superior tympanic a.
- inferior tympanic a.
- anterior tympanic a.
- posterior tympanic a.
PS inn. to parotid gland
CN IX > tympanic n. > middle ear > lesser petrosal n. > otic ganglion > parotid
3 branches of CN VII (internal and middle ear)
- greater petrosal n (GVE-P)
- n. to stapedius (SVE)
- chorda tympani (GVVE-P, SVA)
embryonic origin of middle ear and auditory tube
1st pharyngeal pouch
embryonic origin of malleus, incus, and tensor tympani
1st pharyngeal arch
embryonic origin of stapes and stapedius
2nd pharyngeal arch (ON TEST)
embryonic origin membranous labyrinth and CN VIII ganglia
otic placode
embryonic origin bony labyrinth
surrounding mesenchyme
