C27 - Anatomy of Temporal Bone, External Ear, and Middle Ear

Question 1

Articulations of temporal bone

Answer 1

sphenoid
parietal
occipital
zygomatic

Question 2

superior face of pyramid

Answer 2

middle fossa floor

Question 3

posterior face of pyramid

Answer 3

anterior limit of posterior fossa

Question 4

antero-inferior face of pyramid

Answer 4

muscle attachments of neck and infratemporal fossa

Question 5

base of pyramid

Answer 5

muscular-cutaneous side of the head

Question 6

Four embryologic components of temporal bone

Answer 6

squamous
mastoid
petrous
tympanic

Question 7

lateral wall of middle fossa

Answer 7

squamous part

Question 8

bony roof of glenoid fossa

Answer 8

zygomatic process

Question 9

anterior extension of squamous

Answer 9

zygomatic process

Question 10

insertion of temporalis muscle to squamous

Answer 10

outer cortex

Question 11

insertion of masseter to squamous

Answer 11

zygomatic process

Question 12

horizontal line formed on the most inferior insertion by temporalis muscle on squamous

Answer 12

temporal line

Question 13

aligned with zygomatic process; used as a surface landmark to estimate middle fossa floor

Answer 13

temporal line

Question 14

average offset of temporal line

Answer 14

4.7mm

Question 15

bulbous bony structure shaped by the expansion of air filled spaces within

Answer 15

mastoid part of temporal bone

Question 16

mastoid tip or process was due to

Answer 16

constant pull of scm and posterior belly of digastric

Question 17

perforated by multiple small emissary vessels that drain from central air cell or antrum and form a depressed cribriform area at the anterior junction of mastoid with tympanic

Answer 17

mastoid cortex

Question 18

evident near the posterior limit of the outer mastoid cortex

Answer 18

foramen of single emissary vein

Question 19

evident on posterior medial aspect of temporal bone

Answer 19

sulcus of sigmoid sinus

Question 20

froamen of single emissary vein communicates with

Answer 20

sulcus of sigmoid sinus

Question 21

indictaed by a rough and irregular surface at the mastoid tip

Answer 21

site of scm insertion

Question 22

insertion of posterior belly of digastric

Answer 22

medial to the mastoid tip, in a sulcus that terminates anteriorly at the stylomastoid foramen

Question 23

sulcus for occipital artery

Answer 23

medial and parallel to digastric sulcus

Question 24

base of petrous part of temporal

Answer 24

united with mastoid laterally

Question 25

apex of petrous part

Answer 25

oriented anteromedially between the occipital and sphenoid bones

Question 26

anterior surface of petrous

Answer 26

forms the posteromedial margin of middle fossa floor

Question 27

significant surface features of petrous medially

Answer 27

arcuate eminence

Question 28

arcuate eminence is formed by

Answer 28

prominence of scc and sulcus of superior petrosal sinus

Question 29

anterior of petrous, the junction of greater sphenoid wing, the musculotubal canal contains the

Answer 29

more superficial semicanal of the tensor tympani and a deeper semicanal of eustachian tube

Question 30

smooth depression at petrous apex

Answer 30

trigeminal ganglion

Question 31

posterior to trigeminal ganglion

Answer 31

foramina and sulci of the greater and lesser superficial petrosal nerves, running parallel to sphenoid suture line

Question 32

roof of middle ear and mastoid

Answer 32

located lateral to arcuate eminence

Question 33

posterior surface of petrous part is oriented

Answer 33

in the vertical plane that forms the anterior bony limit of the posterior fossa

Question 34

posterior surface of petrous framed by

Answer 34

sulci for sigmoid, superior petrosal, inferior petrosal sinuses

Question 35

center of posterior surface of petrous

Answer 35

porous acousticus

Question 36

fundus of porous acousticus

Answer 36

falciform (horizontal) crest bill bar (vertical) crest foramina of cn 7 and 8

Question 37

emerges from a depression superior and lateral to the acoustic meatus

Answer 37

subarcuate artery

Question 38

occupies the depression and opening located inferolaterally, known as operculum

Answer 38

endolymphatic sac and duct

Question 39

formed at the junction between the petrous and occipital bones

Answer 39

jugular foramen

Question 40

jugular formane is partitioned into

Answer 40

``` pars nervosa (posterior) pars venosa (anterior) by the jugular spine ```

Question 41

inferior surface of temporal bone is irregular because

Answer 41

presence of multiple muscle attachments

Question 42

external aperture of cochlear duct is located

Answer 42

medial and anterior to the jugular spine within the pars nervosa

Question 43

marks the most superior limit of jugular foramen

Answer 43

external aperture of the cochlear aqueduct

Question 44

enters the jugular foramen adjacent to the opening of the cochlear aqueduct

Answer 44

glossopharyngeal nerve

Question 45

important inferior limit of dissection to protect the lower cranial nerves in the translabyrinthine approach to the internal auditory canal

Answer 45

cochlear aqueduct

Question 46

cochlear aqueduct opens into what structure at the cochlear base

Answer 46

scala tympani

Question 47

occupies a dome shaped compartment located lateral to the pars venosa of jugular foramen, directly under the middle ear space

Answer 47

jugular bulb

Question 48

located directly anterior to the jugular bulb depression which is separated by a wedge shaped bone called the keel

Answer 48

inferior foramen of the carotid canal

Question 49

tympanic cannaliculus penetrates the keel to transmit sensory and prganglionic parasympathetic fibers from the inferior ganglion of the glossopharyngeal nerve into the middle ear as the

Answer 49

jacobson nerve

Question 50

located anterior to the stylomastoid foramen

Answer 50

styloid process

Question 51

both are located at the anterior limit of digastric groove

Answer 51

styloid process and stylomastoid foramen

Question 52

eagle syndrome

Answer 52

odynophagia, dysphagia, foreign body sensation in the throat

Question 53

eagle syndrome brought about by

Answer 53

elongation or angulation of the styloid process, as a result of compression of cranial nerves or the ica

Question 54

froms the anterior wall and floor and part of the posterior wall and roof of the bony eac and the anterior wall of and floor of the middle ear

Answer 54

tympanic part of the temporal bone

Question 55

the anterior edge of the open ring fromed by the tympanic part of the temporal bone froms this structure within the eac

Answer 55

tympanosquamous suture line

Question 56

the anterior edge of the open ring formed by the tympanic part of the temporal bone froms this structure within the middle ear

Answer 56

petrotympanic suture line

Question 57

chorda tympani exits the ear through this structure

Answer 57

petrotympanic suture line

Question 58

this line serves as a land,ark for the main trunk of the facial nerve

Answer 58

tympanomastoid suture line, for,ed by the posterior edge of the tympanic ring which curves from the posterior eac inferiorly to within millimeters of the stylomastoid foramen