Gross Anatomy of the TEMPORAL BONE, EXTERNAL EAR, and MIDDLE EAR M1 Gross and Developmental Anatomy 9:00 AM, December 11, 2008 Dr. Milton M. Sholley Professor of Anatomy and Neurobiology 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. 2
Lateral View of Temporal Bone in situ Fig. 7.3A, page 612 3 Temporomandibular Joint (TMJ) Mandibular fossa -Part of squamous temporal bone Disk Condyloid process (head) of mandible Fig. 7.40A, page 664 4 Fig. 7.46A, page 675
Mastoid process Plane (coronal) of the cut through the temporal bone as seen on the next slide 5 Petrosal Sinuses Inferior Superior Sigmoid sinus Mastoid air cells within the mastoid process Grant s Atlas, 12 6 th Ed. Fig. 7.24B, page 642
Inferior View of Skull showing Temporal Bone (in dark pink) Carotid canal Petrous portion of temporal bone Jugular foramen 7 Foramen ovale Foramen spinosum Spine of sphenoid Mandibular fossa Petrotympanic fissure External auditory meatus Mastoid process Cartilagenous auditory tube Internal carotid artery entering carotid canal Jugular foramen Stylomastoid foramen Inferior View 8
The Cartilagenous Auditory Tube Opens into the Nasopharynx (air can exchange between nasopharynx and the middle ear cavity) Opening of auditory tube (Eustachian tube) Torus tubarius Nasopharynx (space above the soft palate) Soft palate Grant s Atlas, 12 9 th Ed. Fig. 7.61, page 694 Tensor veli palatini muscle Hamulus Pterygomandibular raphe Cartilagenous auditory tube Levator veli palatini muscle Salpingopharyngeus muscle Palatopharyngeus muscle Superior pharyngeal constrictor muscle 10
Tensor veli palatini muscle Hamulus Palatoglossus muscle Cartilagenous auditory tube Levator veli palatini muscle Salpingopharyngeus muscle Superior pharyngeal constrictor muscle Palatopharyngeus muscle 11 Buccinator muscle Superior pharyngeal constrictor muscle Pterygomandibular raphe 12
Superior View of Cranial Fossae shows Petrous Part of Temporal Bone Superior face of petrous pyramid (also called anterior face) Posterior face of petrous pyramid Grant s Atlas, 12 13 th Ed. Fig. 7.6A, page 618 Tegmen tympani Arcuate eminence Hiatus of facial canal Grant s Atlas, 12 14 th Ed. Fig. 7.77A, page 714
Superior View of Petrous Pyramid (drilled out) Internal auditory meatus Greater petrosal nerve Lesser petrosal nerve Geniculate ganglion Malleus Incus Facial nerve (before genu) Facial nerve (after genu) Middle ear cavity Fig. 7.74, page 709 15 Tegmen tympani Arcuate eminence Hiatus of facial canal Grant s Atlas, 12 16 th Ed. Fig. 7.77A, page 714
Anterior (superior) semicircular canal raises arcuate eminence 17 Tegmen tympani Arcuate eminence Hiatus of facial canal Grant s Atlas, 11 18 th Ed. Fig. 7.77A, page 714
Posterior View of Petrous Parts of Temporal Bones Internal auditory meatus Fig. 7.4C, page 615 Posterior face of petrous pyramid 19 Structures seen on Posterior Face of Petrous Pyramid Groove for inferior petrosal sinus Internal auditory meatus Groove for superior petrosal sinus Groove for sigmoid sinus Grant s Atlas, 11 th Ed. Fig. 7.85B, page 706 Opening of cochlear canaliculus Opening of vestibular aqueduct 20
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Auricle Lateral view Scaphoid fossa Triangular fossa Tubercle Crura of antihelix Helix Antitragus Crus of helix Antihelix Concha Tragus Ear lobe Grant s Atlas, 12 23 th Ed. Fig. 7.68A, page 703 Cutaneous Innervation of Auricle Concha (green area)- Auricular branch of vagus (Arnold s nerve) Lateral surface of blue area- Great auricular nerve Medial surface of blue area- Great auricular nerve Lateral surface of red area- Auriculotemporal nerve Free medial surface of red area- Lesser occipital nerve Syllabus, page 466, topic e 24
25 Middle Ear Cavity Horizontal section Lateral Incus Malleus External auditory meatus Tympanic membrane (Eardrum) Facial nerve (in facial canal) Chorda tympani Stapes Middle ear cavity (Tympanic cavity) Auditory tube Anterior Similar to: Grant s Atlas, 26 12 th ed. Figure 7.72A, p. 707
External view of Tympanic Membrane (Eardrum) Pars flaccida Posterior mallear fold Lateral process of malleus Anterior mallear fold Handle of malleus Posterior Pars tensa Umbo Anterior Cone of light Figure 7.71A, page 706 Inferior 27 Incus Middle Ear Cavity Horizontal section Facial nerve (in facial canal) Lateral Malleus Chorda tympani Middle ear cavity (Tympanic cavity) Tympanic membrane (Eardrum) Anterior Similar to: Grant s Atlas, 28 12 th ed. Figure 7.72A, p. 707
Diagram of Middle Ear Cavity Anterior wall removed ROOF Chorda tympani Tympanic membrane LATERAL WALL Malleus Incus Stapes MEDIAL WALL Lesser petrosal nerve Facial nerve in facial canal Tympanic plexus FLOOR Tympanic nerve Figure 7.73A, page 708 Facial nerve beyond stylomastoid foramen 29 Simplified Diagram of Lateral Wall of Middle Ear Cavity (Inside the cavity looking out) 30
Tensor tympani Detailed Diagram of Lateral Wall of Middle Ear Cavity (Inside the cavity looking out) Attic Tegmen tympani Aditus ad antrum Bony auditory tube Tympanic canaliculus Mastoid air cells Chorda tympani Internal carotid artery Facial nerve Internal jugular vein Grant s Atlas, 12th Ed. Figure 7.75D, page 711 31 Lateral Wall of Middle Ear Cavity (Inside the cavity looking out) Attic (or epitympanum) Tensor tympani muscle Bony auditory tube Chorda tympani nerve Eardrum 32 Facial nerve
Epitympanic recess (attic) Malleus Incus Stapes Vestibule External auditory meatus and tympanic membrane Coronal section drawing 33 Medial Wall of Middle Ear Cavity (Inside the cavity looking in) Tensor tympani muscle Greater petrosal nerve Tendon of stapedius muscle Round window Stapes in oval window Promontory of cochlea Bony auditory tube 34
Parts of the Bony Labyrinth (in inner ear) that form the Medial Wall of the Middle Ear Horizontal or lateral semicircular canal Oval window (stapes fits here) Facial canal (for facial nerve) Posterior Anterior Figure 7.77C, page 714 Round window Promontory of cochlea 35 Tympanic Plexus is on the Medial Wall of Middle Ear Tympanic plexus lies on the medial wall of the middle ear (i.e. on the promontory) Jugular foramen Figure 7.75B, page 710 Carotid canal Inferior tympanic canaliculus (tympanic nerve runs through it) Tympanic nerve (branch of CN IX) 36
Diagrammatic Review of Glossopharyngeal Nerve (CN IX) Glossopharyngeal nerve Lesser petrosal nerve Otic ganglion Parotid gland Auriculotemporal nerve Tympanic nerve (branch of glossopharyngeal) Page 835 37 Superior View of Petrous Pyramid (drilled out) Internal auditory meatus Greater petrosal nerve Lesser petrosal nerve Geniculate ganglion Malleus Incus Facial nerve (before genu) Facial nerve (after genu) Middle ear cavity Fig. 7.74, page 709 38
Diagrammatic Review of Facial Nerve page 831 39 Review of Facial Nerve page 831 40
End of Part 1 41 Radiologic Anatomy Practice Questions Head 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. 42
A. Identify the black area indicated by the arrow. B. The bony structures indicated by the yellow arrows are the. 43 A. Identify the black area indicated by the red arrow. B. Identify the bony structure indicated by the red arrow. 44
A. The yellow arrows indicate the. B. Identify the black area indicated by the red arrow. 45 A. The yellow arrows indicate the. B. Identify the structure indicated by the red arrow. 46
A. Identify the soft tissue structure indicated by the red arrow. B. The yellow arrow indicates the. 47