TEMPORAL BONE,EXTERNAL EAR,

and

MIDDLE EAR

of theGross Anatomy

M1 Gross and Developmental Anatomy9:00 AM, December 11, 2008

Dr. Milton M. SholleyProfessor of Anatomy and Neurobiology

2

Assignment: Head to Toe 2006

• Concerning the material that I will present on the Temporal Bone and Ear, I would recommend that everyone work the following questions from Head to Toe 2006: #7, #10, #65, #88, #97, #100, #104, #118, #121, #157, and #164. By working the questions, I mean that you should read and understand the hints and explanations, even if you get a question correct on your first attempt.

3

Lateral Viewof

Temporal Bonein situ Grant’s Atlas, 12th Ed.

Fig. 7.3A, page 612

4

Temporomandibular Joint (TMJ)

Mandibular fossa-Part of squamous

temporal bone

Disk

Condyloid process (head)of mandible

Grant’s Atlas, 12th Ed.Fig. 7.40A, page 664

Grant’s Atlas, 12th Ed.Fig. 7.46A, page 675

5Plane (coronal) of the cut through the temporal bone as seen on the next slide

Mastoid process

6

Mastoid air cellswithin the mastoidprocess

Sigmoid sinusSuperiorInferior

Petrosal Sinuses

Grant’s Atlas, 12th Ed.Fig. 7.24B, page 642

7

Inferior Viewof

Skullshowing

Temporal Bone(in dark pink)

Petrous portionof temporal bone

Carotid canal

Jugular foramen

8

Foramen ovale

External auditorymeatus

Mandibular fossaCartilagenousauditory tube

Internal carotid arteryentering carotid canal

Jugular foramen

Stylomastoid foramen

Inferior View

Mastoid process

Petrotympanic fissure

Spine of sphenoid

Foramen spinosum

9

The Cartilagenous Auditory TubeOpens into the Nasopharynx

(air can exchange between nasopharynx and the middle ear cavity)

Nasopharynx(space abovethe soft palate)

Soft palate

Opening of auditorytube (Eustachian tube)

Torus tubarius

Grant’s Atlas, 12th Ed.Fig. 7.61, page 694

10

Cartilagenousauditory tube

Tensor velipalatini muscle

Hamulus

Levator veli palatini muscle

Salpingopharyngeus muscle

Palatopharyngeus muscle

Superior pharyngealconstrictor musclePterygomandibular

raphe

11

Cartilagenousauditory tube

Tensor velipalatini muscle

Levator veli palatini muscle

Salpingopharyngeus muscle

Palatopharyngeus muscle

Hamulus

Palatoglossusmuscle

Superior pharyngealconstrictor muscle

12

Superior pharyngealconstrictor muscle

Pterygomandibular raphe

Buccinator muscle

13

Superior Viewof

Cranial Fossaeshows

Petrous Partof

Temporal Bone

Superior faceof petrouspyramid (alsocalled anteriorface)

Posterior faceof petrouspyramid

Grant’s Atlas, 12th Ed.Fig. 7.6A, page 618

14

Hiatus of facial canal

Arcuate eminence

Tegmen tympani

Grant’s Atlas, 12th Ed.Fig. 7.77A, page 714

15

Superior View of Petrous Pyramid(drilled out)

Greater petrosal nerveLesser petrosal nerve

Geniculate ganglion

Facial nerve(before genu)

Facial nerve(after genu)

Internal auditory meatus

Malleus

Incus

Middle ear cavity

Grant’s Atlas, 12th Ed.Fig. 7.74, page 709

16

Hiatus of facial canal

Arcuate eminence

Tegmen tympani

Grant’s Atlas, 12th Ed.Fig. 7.77A, page 714

17

Anterior (superior)semicircular canalraises arcuate eminence

18

Hiatus of facial canal

Arcuate eminence

Tegmen tympani

Grant’s Atlas, 11th Ed.Fig. 7.77A, page 714

19

Posterior faceof petrouspyramid

Posterior Viewof

Petrous Partsof

Temporal Bones

Internal auditorymeatus

Grant’s Atlas, 12th Ed.Fig. 7.4C, page 615

20Opening ofvestibular aqueduct

Opening ofcochlear canaliculus

Internal auditorymeatus

Groove forinferior petrosal sinus

Groove for superiorpetrosal sinus

Groove forsigmoid sinus

Structures seen on Posterior Face of Petrous Pyramid

Grant’s Atlas, 11th Ed.Fig. 7.85B, page 706

21

22

23

AuricleLateral view

Ear lobe

AntitragusTragus

Helix

Tubercle

ConchaAntihelix

Crus of helix

Crura of antihelixTriangular fossa

Scaphoid fossa

Grant’s Atlas, 12th Ed.Fig. 7.68A, page 703

24

Cutaneous Innervation of Auricle

Concha (green area)-Auricular branch of vagus(Arnold’s nerve)

Lateral surface of red area-Auriculotemporal nerve

Free medial surface of red area-Lesser occipital nerve

Lateral surface of blue area-Great auricular nerve

Medial surface of blue area-Great auricular nerve

Syllabus, page 466, topic e

25

26

Middle Ear CavityHorizontal section

Similar to: Grant’s Atlas, 12th ed.Figure 7.72A, p. 707

Middle ear cavity(Tympanic cavity)

Stapes

Auditory tube

Tympanic membrane(Eardrum)

Externalauditory meatus

Malleus

Incus

Lateral

Ant

erio

r

Facial nerve(in facial canal)

Chorda tympani

27

External view of Tympanic Membrane (Eardrum)

Posterior Anterior

Inferior

Pars flaccida

Pars tensa

Handle of malleus

Lateral process ofmalleus

Anterior mallear foldPosterior mallear fold

Cone of light

Umbo

Grant’s Atlas, 12th Ed.Figure 7.71A, page 706

28

Middle Ear CavityHorizontal section

Middle ear cavity(Tympanic cavity)

Tympanic membrane(Eardrum)

Malleus

Incus

Lateral

Ant

erio

r

Chorda tympani

Facial nerve(in facial canal)

Similar to: Grant’s Atlas, 12th ed.Figure 7.72A, p. 707

29

Diagram of Middle Ear CavityAnterior wall removed

Malleus

Incus

Stapes

Tympanic plexus

ME

DIA

L W

AL

L

LA

TE

RA

L W

AL

L

FLOORTympanic nerve

Lesser petrosal nerve

Facial nerve beyondstylomastoid foramen

Facial nerve infacial canal

Tympanicmembrane

Chorda tympani

Grant’s Atlas, 12th Ed.Figure 7.73A, page 708

ROOF

30

Simplified Diagram of Lateral Wallof Middle Ear Cavity

(Inside the cavity looking out)

31

Detailed Diagram of Lateral Wallof Middle Ear Cavity

(Inside the cavity looking out)

Grant’s Atlas, 12th Ed.Figure 7.75D, page 711

Internal jugular vein

Internal carotid artery

Bony auditorytube

Facial nerve

Aditus ad antrum

Tympanic canaliculus

Tensor tympani

Chorda tympani

Mastoid air cells

Tegmen tympaniAttic

32

Tensor tympanimuscle

Chorda tympaninerve

Facial nerve

Lateral Wall of Middle Ear Cavity(Inside the cavity looking out)

Bony auditorytube

Eardrum

Attic (or epitympanum)

33

Epitympanicrecess (attic)

Malleus

Incus

Stapes

Vestibule

External auditory meatusand tympanic membrane Coronal section drawing

34

Medial Wall of Middle Ear Cavity(Inside the cavity looking in)

Tensor tympanimuscle

Bony auditorytube

Promontory ofcochlea

Round window Stapes inoval window

Tendon ofstapedius muscle

Greater petrosalnerve

35Round window

Oval window (stapes fits here)

Promontory of cochlea

AnteriorPosterior

Parts of the Bony Labyrinth (in inner ear)that form the Medial Wall of the Middle Ear

Horizontal or lateralsemicircular canal Facial canal

(for facial nerve)

Grant’s Atlas, 12th Ed.Figure 7.77C, page 714

36

Tympanic Plexus is on the Medial Wall of Middle Ear

Tympanic plexus lies onthe medial wall of themiddle ear (i.e. on thepromontory)

Jugular foramen

Carotid canal

Tympanic nerve(branch of CN IX)

Inferior tympanic canaliculus(tympanic nerve runs through it)

Grant’s Atlas, 12th Ed.Figure 7.75B, page 710

37

Diagrammatic Review of Glossopharyngeal Nerve (CN IX)

Grant’s Atlas, 12th Ed.Page 835

Glossopharyngealnerve

Tympanic nerve(branch of glossopharyngeal)

Lesser petrosal nerve

Otic ganglion

Auriculotemporal nerve

Parotid gland

38

Superior View of Petrous Pyramid(drilled out)

Greater petrosal nerveLesser petrosal nerve

Geniculate ganglion

Facial nerve(before genu)

Facial nerve(after genu)

Internal auditory meatus

Malleus

Incus

Middle ear cavity

Grant’s Atlas, 12th Ed.Fig. 7.74, page 709

39

Diagrammatic Review of Facial Nerve

Grant’s Atlas, 12th Ed.page 831

40

Review of Facial Nerve

Grant’s Atlas, 12th Ed.page 831

41

End of Part 1

42

Radiologic Anatomy Practice QuestionsHead and Neck

2008

Here are the practice questions.You can look up the answers in the Radiologic Anatomy Program.

For confirmation of the answers, come to Dr. Sholley’s Review.

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B. The bonystructuresindicated by theyellow arrowsare the _______.

A. Identify theblack areaindicated bythe arrow.

44

B. Identifythe bony structureindicated by thered arrow.

A. Identify theblack areaindicated bythe red arrow.

45

A. The yellowarrows indicatethe _________.

B. Identifythe black areaindicated by thered arrow.

46

A. The yellowarrows indicatethe _________.

B. Identifythe structureindicated by thered arrow.

47

B. The yellowarrow indicatesthe _________.

A. Identifythe soft tissuestructureindicated by thered arrow.