Anatomy Iii

Front 1

Occipitofrontalis

Back 1

Digastric muscle attaches at the superior nuchal line,and the subcutaneous tissue of the eyebrows and forehead.

Action: independent contraction of the occipital belly retracts the brows and contraction of the frontal body protracts it.

innervation: facial nerve

Front 2

Obicularis Oris

Back 2

encircles the mouth and controls entry into the oral fissure. Also important for articulation.

Attachments: mandible, medial maxilla, angle of the mouth.

Action: Tonic-closes the mouth
Phasic- compresses and protrudes lips

innervation: facial nerve

Front 3

Buccinator

Back 3

Thin flat rectangular muscle that attaches to the lateral maxilla and lateral mandible opposite the molar teeth.

more medial in the mandible, so deep to all other muscles, so more closely related to buccal mucosa than skin of the face.

Innervated: facial nerve

keeps the cheek taut, and keeps the checks from getting bitten. also involved in smiling.

Front 4

Muscles involved in keeping food between occlusal surfaces of teeth, and prevent food from accumulating in the oral fissure.

Back 4

obicularis oris, buccinator, and tongue

Front 5

Obiculariris Oris and Buccinator

Back 5

Keep the cheeks and lips taught against the teeth.

Front 6

Platysma

Back 6

Attachments: subcutaneous tissue of the supraclavicular and infraclavicular regions.

base of the mandible, skin of the cheek angle of the mouth and obicularis oris.

Action: superior: tenses the skin and creates vertical lines
inferior: depresses mandible, draws corners of the mouth down as in a grimace

Innervation:facial nerve

Front 7

Levator Anguli Oris

Back 7

Attachments: -maxilla immediately inferior to infraorbital foramen
-fibers combine with the obicularis oris

Action: lifts the angles of the mouth.
Innervation:facial nerve

Front 8

Depressor Anguli Oris

Back 8

Attachments: the base of the mandible, and the ascending fibers combine with the fibers of the obicularis Oris.

Action: Depress the corners of the mouth

Innervation: facial nerve.

Front 9

Zygomaticus Major and Minor

Back 9

Atachments: Zygomatic Bone, fibers go medially and downward to blend with the fibers of the obicularis oris

Action: pulls angles of the mouth upwards and backwards

Innervation: facial nerves

Front 10

Orbicularis Oculi

Back 10

Originates-medial orbital margin and lacrimal bone
-inserts: into skin around orbit

Action:Palpebral- blinking
orbital-forceful closing

innervation: facial nerve

Front 11

Parotid Gland

Back 11

Wedged between ramus of the mandible and the mastoid process. The base is related to the zygomatic arch and the apex is posterior to the angle of the mandible

Enclosed in a tough facial capsule called parotid sheath.
Fatty tissue between the lobes of the gland ensure flexibility of the gland during mastication.

Front 12

Parotid Duct

Back 12

passes horizontally from the anterior borders of the parotid gland, and the masseter muscle, pierces the buccinator and enters the oral cavity through a small orifice.

Front 13

embeded in the parotid gland, superficial to deep

Back 13

parotid plexus of the facial nerve-CN VII and its branches

retromandibular vein- draingage from superficial face

external carotid artery

Front 14

Carotid Arteries

Back 14

Bifurcate at the level of the superior border of the thyroid cartilage

Internal: deep to every muscle in the face and becomes the primary blood supply to the brain and orbit

External: generally supplies the structures external to the skull. runs posterosuperiorly to the space between the neck and the mandible.

Front 15

Orbital Plates

Back 15

on the floor of the frontal bone of the anterior cranial fossa. separates the anterior cranial fossa from the orbits

Front 16

Cribiform plate and Crista Galli

Back 16

separates the ethmoid bone of the anterior cranial fossa from the nasal cavity. has small perforations to transmit olfactory nerve fibers CN 1 into the nasal cavity.

the crista galli is the median, crest-like elevation on the ethmoid bone that is the attachment sight for dura matter.

Front 17

Sphenoid

Back 17

lesser wing and body of sphenoid contribute to the anterior cranial fossa.

body of sphenoid also contributes to the middle cranial fossa, and includes

-the chiasmatic groove: the location of the optic chiasm.

-Sella Turcica: large part of teh body of the sphenoid.

Front 18

Sella Turcica

Back 18

Tuberculum sellae: the bony projection immediately posterior to the chiamatic groove

Hypophyseal fossa: deepest part of the sella turcica, articulates with pituatary glamd

Dorsum sallae: posterior plate that forms the posterior boundry of the sella turcica | posterior clinoid process, projections off the sides of the dorsum sallae, serve as attacchment sight for dura matter

Front 19

Anterior Clinoid process

Back 19

posterior projections off the lesser wing of the sphenoid. serve as attachment sights for dura matter.

Front 20

Greater wing of the Sphenoid

Back 20

contributes to the floor of the middle cranial fossa. can be seen from the lateral and inferior views of the skull as well.

Front 21

Openings of Sphenoid bone

Back 21

Optic canal: passes forward to the orbit and transmits the Optic Nerve CN II to the obrits

Superior Orbital Fissure: comma shaped fissure between the greater and lesser wings of the sphenoid and transmit Cranial nerves CN III-oculomotor, CN IV-trochlear, CN VI-abducens, and (CN) V-1.

Front 22

Openings contributing to Sphenoid and Temporal bones

Back 22

Carotid Canal: internal opening, found at the juntion of the greater wing of sphenoid and the petrous portion of the temporal bone.

Foramen Lacerum: found at the juncture of the greater wing and body of the sphenoid and the apex of the petrous portion of the temporal bone. lwer margin is filled with cartilage, in life. and contributes to the floor of the carotid canal.

Front 23

Temporal Bone

Back 23

Morphologically distinct regions: squamous, petrous, mastoid tympanic and styloid process

Squamous (smooth part) and Petrous (rough) portions can been seen superiorly in the middle cranial fossa.

Front 24

Posterior Cranial Fossa

Back 24

-Anterolateral wall is formed by the petrous portion of the temporal bone

-Clivus: comprised of the part of the sphenoid immediately posterior to the dorsum salle, as well as the basilar portion of the occipital bone; directly anterior to the Foramen Magnum.

Squamous Portion of Occipital Bone: portion of the occipital bone that borders the Foramen Magnum posterior (and laterally)

Internal Occipital Protuberance: midline posterior elevation at the posterior pole of internal occipital bone.

Front 25

Openings of the Posterior Cranial Fossa

Back 25

Foramen Magnum: big opening through with the medulla is continuous with the spinal cord.

Hypoglossal Canal: openings directly anterolateral to the Foramen Magnum. transmits the cranial nerve CN XII- hypoglossal nerve

Jugular foramen: opening on the posterior slope of the petrous portion of the temporal bone, at the juncture of the temporal and occipital bones. transmits the cranial nerves CN IX-glossopharengeal, CN X-Vagus and CN XI-accessory

Internal Acoustic Meatus: On the posterior slope of the petrous portion, above the jugular foramen, transmits the cranial nerves CN VII-facial nerve and (CN V) V-3

Front 26

Transverse Lines

Back 26

Anterior Transverse Line: conects between the articular eminences.

Posterior Transverse Line: anterior aspects of left and right mastoid processes

Front 27

Posterior Nasal Spine

Back 27

a midline posterior projection

Front 28

Incisive foramen

Back 28

most anterior foramen of the palatine process of the maxilla. transmits the nasopalatine nerve and vessels

Front 29

Greater Palatine Canal

Back 29

Greater Palatine Foramen: transmits the greater palatine nerve and vessels

lesser palatine foramen: transmits lesser palatine nerves and vessels

Front 30

Foramen Spinosum

Back 30

directly anterior to the spine of teh sphenoid and transmits the middle meningeal artery from the base of the skull to the interior of the skull.

Front 31

Spine of Sphenoid

Back 31

Ligament joins spine to the lingula of the mandible.

Front 32

Stylomastoid Foramen

Back 32

allows for passage of CN VII-facial nerve from within temporal bone.

Front 33

Posterior Triangle

Back 33

Borders: Sternocleidomastoid, trapezius and inf. aspect of omohyoid

contents: cervical plexus, accessory nerve, trunks of brachial plexus, lymph nodes and cervical arteries

Front 34

Omoclavicular triangle

Back 34

borders: inf. belly of omohyoid, sternocleidomastoid and clavical

contents: subclavian artery, subclavian vein, lymph nodes and suprascapular artery