This Lcd Projector

This LCD projector Is donated by the USA based SWU MHAM Medical Alumni to the Anatomy Depar tment and received by Dr. Allan Libr ando, Chair man. T his pr oject is Initiated by: Dr. Halber t Capuy Dr. Lorens Alaan Dr. Mel Alle go ( Pr esident) Other USA based Medical pr actitioner s who attended the SWU 60 th Diamond Jubilee anniver sar y in Januar y 11 – 14, 2007

Head and neck

The skull

The Neurocranium bones • • • • • • >

Frontal bone Parietal bones ( paired) Temporal bones ( paired) Occipital bone Sphenoid bone Ethmoid bone Largely flat, curved and united by fibrous interlocking sutures.

Facial skeleton

)

( viscerocranium or splanchnocranium

• • • • • • • •

Lacrimal bones ( 2 ) Nasal bones ( 2 ) Maxillae ( 2 ) Zygomatic bones ( 2 ) Palatine bones ( 2 ) Inferior nasal conchae ( 2 ) Mandible ( 1 ) Vomer ( 1 )

Anterior Skull • Glabella – the smooth slightly depressed area between the superciliary arches.

• Nasion – the intersection of the frontal and the nasal bone ( bridge 0f the nose) • Supraorbital arch – the angular boundary between the squamous and orbital bones. •

Supraorbital notch or foramen – passage for vessels and nerves.

• Superciliary arch – a ridge superior and lateral to the glabella. • Orbital fissures – superior and inferior • Optic canal – for passage of optic nerve

Anterior Skull • • •

Zygomatic bones ( zygoma, cheekbone, malar bone) Zygomatico facial foramen Piriform apertures – pear shaped anterior nasal

• • •

Nasal septum – bony divide of the nasal cavity Nasal conchae – curved bony plates on the lateral wall Maxillae – the upper jaw (alveolar processes for the

• • • •

apertures

maxillary teeth ).

Infraorbital foramen – passage for the infraorbial nerves Mandible – U shaped bone with alveolar process for the mandibular teeth Mental foramina – for the mental nerve and vessels. Mental protuberance – prominence of the chin.

Clinical applications • Injury to Superciliary arches – laceration with profuse bleeding, • Blackeye – bruising and bleeding of tissues around the orbit with hematoma formation. • Malar flush – redness of the skin covering the zygomatic prominence.e.g. fever in PTB • Le Fort Fracture - Fractures of the maxillae, alveolar process, bony nasal septum, lacrimal, pterygoid plates of the sphenoid, bridge of the nose. • Resorption of alveolar bones – due to loss of teeth. • Mandibular prognathism – decrease in vertical facial dimensions with overclosure due to total loss of teeth.

Clinical… • a. b. c. d.

Fractures of the Calvaria – Depressed fracture Linear fracture Comminuted fracture Contrecoup fracture (counterblow)

Lateral aspect of the skull • Pterion – the union of frontal, parietal, sphenoid and temporal bones. Importance - It overlies the anterior branch of the middle meningeal artery. • Temporal fossa – boundaries; superior/posterior by temporal lines, inferiorly by the zygomatic arch.

• Zygomatic arch – formed by the union of the temporal process of zygomatic and zygomatic process of temporal bone

• External acoustic meatus – • Mastoid process – • Infratemporal fossa – space inferior and deep to the zygo arch, mandible and posterior maxilla.

Posterior aspect of the skull • Occiput – temporal

from occipital,parietal,mastoid part of

• Inion - Occipital protuberance • Foramen magnum – large opening at the base • Superior nuchal line • Lambda – the junction of the sagittal and lambdoid sutures

Superior aspect of skull • Parietal eminence – • Frontal eminence • Coronal sutures – separates frontal and parietal bone • Sagittal sutures – separates parietal bones • Lambdoid sutures – separates the parietal and temporal bone from occipital bone • Bregma – intersection of sagittal and coronal sutures. • Vertex – most superior point of the skull • Parietal foramen – found posteriorly near the sagittal sutures, transmits emissary veins.

Landmark

Shape and location

Pterion

G. Wing sphenoid

Lambda Bregma(forepart of head)

Vertex Asterion Glabella Inion ( back of head)

Pt. of coronal/sagittal sutures Pt. of coronal/sagittal sutures Superior part of skull Starshaped, parietomastoid, occipitomastoid and lambdoid sutures At the root of the nose Prominent at external occipital protuberance

SCALP • S – Skin • C – Subcutaneous tissue • A - Aponeurosis • L – Loose connective tissue • P - Periostium

Muscles of facial expression • Buccinator - this is the muscle of the cheek. It is used in whistling and sucking and is also involved in mastication. • Zygomaticus minor - it elevates the upper lip in order to show contempt and deepens the nasolabial sulcus to express sadness. • Levator anguli oris - this raises the corner of the mouth. • Depressor labii inferioris - it depresses the lip and is used in the expression of impatience. • Levator labii superioris - this elevates and everts the upper lip and aids the zygomaticus minor muscle in the expression of sadness. • Risorius - this is involved in grinning. • Procerus - this small muscle runs from the bridge of the nose to the forehead and is useful in frowning and in reducing the glare of bright lights. • Platysma - this is a sheet-like muscle which covers the neck and lower face. It has an embryological role related to the facial nerve.

Facial muscles

Facial expression

1. Orbicularis oris Oral sphincter, pucker, whistle

2. Dilator muscles Open mouth wide 3. Levator labii superioris alaque nasi

Elevate upper lip and wing of nose

4. Mentalis

Expression of doubt

5. Buccinator

Aids in mastication, blowing Frowning,depress angle mouth

6. Depressor anguli oris 7. Procerus

8. Levator anguli oris

Draws eyebrow inferior, frown Elevates corner of mouth

Smile, laughing

Muscles of the Nose • Procerus small slip from frontalis, draws eyebrow inferiorly as in frowning or from glare. • Depressor septi, from maxilla into mobile part of nasal septum. Helps in deep inspiration • Nasalis – main muscle, composed of the a. compressor naris – transverse, compress the piriform aperture ( nostril) b. dilator naris – alar (wing) part, from maxilla to alar cartilage * All innervated by buccal branch of facial nerve

Branches of Facial nerve • Temporal -

cross the parotid, to auriclaris, occipito

frontalis & orbicularis oculi.

• Zygomatic – inferior orbicularis occuli, inferior of eye.

• Buccal – buccinators, orbicularis oris, lev. labii sup. • Mandibular – risorius & muscles of lower lip/chin. • Cervical – platysma and superficial neck muscles.

Facial nerve injury Injury results to paralysis of the affected muscles. 1. Inflammation at the stylomastoid foramen produces edema and swelling and compression of the nerve. 2. Loss of tonus of orbicularis oculi > eversion of lower lid 3. Cornea cannot be lubricated, becomes dry, ulcerations or keratitis 4. Patient cannot blow, whistle or chew effectively. Weakens the buccinator, orbicularis oris, cheek and lip muscle. Results to displacement and drooping of mouth corners due to contraction of unopposed contralateral facial muscles cause saliva and food dribbling at the sides of the mouth.

Nerves of the face • Trigeminal nerve (C.n.V)–

sensory nerve of the face, and motor nerve for mastication • Branches of the Trigeminal ganglion: a. Ophthalmic nerve***** 1. nasociliary nerve 2. Frontal nerve 3. Lacrimal nerve b. Maxillary nerve c. Mandibular nerve , sensory part

Ophthalmic nerve Cutaneous branches: a. external nasal nerve b. infratrochlear nerve c. supratrochlear nerve d. supraorbital nerve e. lacrimal nerve

Maxillary nerve •

Cutaneous branches 1. Infraorbital nerve – to the upper cheek, mucosa of maxillary sinus, incisors, canine, premolar, upper gingiva, inferior eyelids, nose, skin and mucosa of upper lip. 2. Zygomaticotemporal nerve – to the temple 3. Zygomaticofacial nerve – to the face at the zygoma

Mandibular nerve Cutaneous Branches • Auriculotemporal nerve – to the auricle, external acoustic meatus, tympanic membrane. • Buccal nerve – to the buccinator, mucosa of cheek and gingiva • Mental nerve – to the chin mucous membrane of lower lip and inferior labial fold.

Facial Vasculature • Mostly from the External carotid artery 1. Facial artery – cervical branches; ascending palatine, tonsillar, glandularSMG,submental, muscular. facial br.;inferior/sup. Labial, Lateral nasal,muscular & angular

2. Superficial temporal artery – transverse facial, medial temporal, anterior auricular, frontal & parietal.

3. Maxillary artery , composed of 3 parts

1st part(bet. Mandibular/sphinopalatine) = ant. Tympanic, deep auricular, middle meningeal(cranial via for.ovale), accessory meningeal, inferior alveolar to mandible, gingiva, teeth.

Maxillary artery, continue… st • 1 part – branches thru foramen and canals, ant. Tympanic, deep auricular, middle meningeal (cranial via for.ovale), accessory meningeal, inferior alveolar to mandible, gingiva, teeth. * 2nd part - supplies muscles, 2 deep temporals, pterygoids, masseteric, buccal arteries rd • 3 part - accompanied by maxillary nerve thru bony canal, lie at [pterygopalatine fossa lateral to the ganglion. branches; posterior superior alveolar, infraorbital, descending palatine, artery of pterygoid canal, pharyngeal, sphenopalatine. * Features: there are 5 branches from each part, first 5 reach destination by entering foramina, middle 5 supply soft tissue & use no foramina, last 5 use foramina. The infraorbital the 6th branch is really the termination of the maxillary artery.

Other clinical facts of the facial vasculatures •

• • • •

Compression of facial artery on one side cannot stop any bleeding due to anastomoses of its branches and other facial vessels. Facial wounds bleed freely and heal quickly. Pulses of the Facial arteries; a. temporal pulse, just anterior to auricle b. facial pulse, at inferior border of mandible Transverse facial artery from the superfacial temporal artery supply the parotid gland and duct, masseter and skin of face anastomose with facial artery. There are anastomoses in the head between the branches of the internal and external carotid artery. Branches of the Post. Sup. Alveolar supply the gum, molar, premolars and maxillary sinus.

Other clinical features… • Branches of the infraorbital artery supply the orbital structures, maxillary sinus, via the anterior superior alveolar branch of canine and incisor teeth. • Descending palatine artery divides into greater and lesser palatine arteries. • The pharyngeal branch via the pharyngeal canal supplies the pharynx posterior to the auditory tube. • The sphenopalatine artery passes thru the sphenopalatine foramen and supplies the lateral wall and septum of nasal cavity.

Facial venous drainage • • • • •

Supratrochlear vein Supraorbital vein Facial vein Superfacial temporal vein Retromandibular vein

Infratemporal fossa and its contents • An irregular shaped space lying behind the maxilla, deep to the ramus of the mandible and inferior to the temporal bone. • Boundaries: Lateral = ramus of mandible Medial = lateral pterygoid plate Anterior = infratemporal surface of maxilla Posterior = anterior surface of condylar process of mandible, styloid process of temporal bone. Roof = inferior surface of greater sphenoid wing. Inferior = insertion of medial pterygoid to the mandible near the angle

Infratemporal fossa , continue… Contents: • Lower part of temporalis muscle • Medial and lateral pterygoid muscles • Maxillary artery and branches • Pterygoid plexus of veins • Mandibular division of Trigeminal nerve ** • Chorda tympanni (cn.Vll) • Otic ganglion

Mandibular division of Trigeminal nerve and its branches 1. Inferior alveolar nerve 2. Nerve to mylohyoid muscles 3. Lingual nerve 4. Buccal nerve 5. Auriculotemporal nerve 6. Nerves to muscles of mastication Mandibular nerve block = local anesthesia

thru 2 routes: extraoral = via the mandibular notch, anesthesia to the auriculo temporal, inferior alveolar, lingual, buccal nerve, skin. Intraoral = thru the buccal mucosa & buccinator muscle medial to mandibular ramus, near foramen. Affects the inferior alveolar and lingual nerve to mandibular body, ramus, mandibular teeth and gingiva, mucosa of anterior 2/3 of tongue.

Triangles of the Neck Cervical Triangles Anterior

Anterior triangle: Ventrally by midline, SCM lateral, cephalic by body of mandible Subdivisions: 1. Digastric (submandibular) = sup. by mandible, anterior and below by digastric ant. belly, post below by digastric and stylohyoid muscles 2. Carotid = sup. by post belly digastric & stylohyoid, inf. by sup.belly omohyoid, post. by SCM 3. Submental (suprahyoid) = lat. by ant. belly digastric, inferiorly by hyoid, medially by midline of neck. 4. Muscular = post. & inferior by SCM, post. & superior by sup.belly omohyoid, medially by midline from hyoid to sternum.

Posterior triangle: anterior by SCM, posterior by trapezius, inferior by clavicle Subdivisions: 1. Occipital triangle = posterior by trapezius, anterior by SCM, caudally by inferior belly omohyoid. 2. Subclavian ( omoclavicular) = anterior by SCM, Superior by inferior belly omohyoid, inferiorly by clavicle

Cervical fascia • Superficial =

covers the ant. and post. Triangle, splits to enclose SCM and trapezius. Attaches to ext. occipital protuberance. Lig. Nuchae, C7 spine, sup. Nuchal line, mastoid process, mandible, clavicle, manubrium, acromion, scapular spine.

• Fascia of Infrahyoid muscle = Superficial

enclose the sternohyoid and omohyoid, DEEP invests the sternohyoid and thyrohyoid muscles.

• Visceral fascia

= encloses the pharynx, larynx, trachea, esophagus, thyroid. Parts pretracheal encloses larynx and trachea, Buccopharyngeal covers the buccinator and posterior esophagus.

• Prevertebral fascia •

= encloses the vertebral column and its muscles. Covers the prevertebral muscles and forms the floor of posrterior triangle. Sibsons fascia ( suprapleural membrane deep to the scalene muscle) covers the cervical pleura.

Carotid sheath • An investment (cover) of the: 1. internal carotid 2. common carotid arteries 3. Internal jugular veins 4. Vagus nerve. • It is adherent to the thyroid sheath and fascia under the SCM. • Attachment, cepahlically bone at jugular foramen and carotid canal, caudally continues to the thorax.

Veins of the neck • Internal jugular vein,

start in jugular fossa as continuation of

Sigmoid sinus. Tributaries : 1. inferior petrosal sinus & meningeal veins 2. pharyngeal plexus veins 3. common facial veins 4. lingual veins, 5. superior thyroid veins thyroid veins 6. middle thyroid veins 7. right lymphatic ducts or the left thoracic duct.

• External jugular vein

= formed by the posterior retromandibular and posterior auricular veins. Tributaries: 1. posterior auricular, occipital, retromandibular and anterior jugular vein 2. posterior external jugular from cephalic part of back of neck. 3. Transverse scapular from scapular region 4. Transverse cervical

• Subclavian vein = from

axillary veins. Tributaries: 1. external jugular 2. transverse cervical 3. thoracoacromial from shoulder and upper pectoral region.

Arteries of the Head and Neck 1. 2. 3. 4. 5. 6.

Common carotids Vertebral arteries Basilar arteries Posterior cerebral arteries Subclavian artery branches External carotid artery and its branches

Common carotid artery • • • 1.

2. 3.

Left arise from the arch independently In the carotid sheath with internal jugualr vein and vagus nerve. Division: Internal carotid, S shaped curved artery, divides into middle and anterior cerebral artery with branches to the: A. middle ear ( caroticotympanic) B. cavernous sinus nerves, trigeminal ganglion, hypophysis and choroid plexus C. Ophthalmic artery to the orbit Middle cerebral artery to the frontal and temporal lobe to the cerebrum Anterior cerebral artery to the corpus callosum. Both cerebrals are terminal and have no collateral circulations and occludes easily.

Vertebral artery • A branch of the subclavian. Runs superiorly to the verterbral column and enters the transverse process C6 • Vertebral supplies: muscles, vertebral column, spinal column meninges, medulla, pons, cerebellum and cerebrum. • Spinal branches enters intervertebral foramina to supply the cord. • Last branch of the vertebral is the Posterior Inferior Cerebellar artery.

Basilar artery, • terminates in the interpeduncular cistern and divides into right and left cerbral. 1. Pontine = to pons, ventrolateral cerebellar cortex, inferior midbrain 2. Internal auditory = to dura of canal, cochlea, labyrinth, facial nerves 3. Anterior inferior cerebellar = to brain stem, superior and middle cerebellar peduncle, anterior cerebellar hemisphere 4. Superior cerebellar = to the inferior colliculi, superior cerebellar peduncle and dentate nerve 5. Posterior Cerebral artery

Posterior cerebellar artery Branches:

a. posteromedial ganglion to hypothalamus, thalamus, choroid plexus and 3rd ventricle. b. posterior choroidal branch, thalamus, subthalamus, internal capsule, choroid plexus, 3rd ventricle, lateral ventricle c. cortical branch = to inferior surface of temporal and occipital lobes

External carotid artery, branches: 1. 2. 3. 4. 5. 6. 7. 8.

Superior thyroid = infrahyoid region, larynx, thyroid gland Ascending pharyngeal = pharynx, prevertebral muscles, meninges, soft palate Lingual = tongue, suprahyoid, sublingual gland, palatine tonsils. Facial = submandibular gland, lips, nose, facial muscles, angle of eye Occipital = to SCM, meningeal branches, scalp Posterior auricular = tympanic membrane, external ear, posterior scalp. Superficial temporal = parotids, ear, face, zygomatic and temporal regions. Maxillary artery = to masticatory muscles

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