Head Factoids

Cranium

Neurocranium: bony covering of brain and meninges; calvaria is dome-like roof, cranial base is floor. Made up of frontal, ethmoidal, sphenoidal, occipital, 2x temporal and 2x parietal bonesViscerocranium: facial bones; mandible, ethmoid, vomer, 2x maxilla, 2x inf nasal conchae, 2x zygomatic, 2x palatine, 2x nasal, 2x lacrimalNB. External occipital crest descends from ex occipital protuberance (inion), sup nuchal line extends laterally from protuberance; hard palate formed by palatine processes of maxilla and horizontal plates of palatine bones; post border of hard palate forms post nasal spine; choanae (post nasal apertures) are separated from each other by the vomer (forms part of nasal septum); sphenoid is composed of greater and lesser wings and pterygoid processes (consisting of lat and med pterygoid plates); cranium articulates with vertebral column via occipital condyles; internal cranial base split into ant (highest), middle and post (lowest) cranial fossa; bones consist of in and ex tables of compact bone separated by diploe (cancellous bone)Sella turcica is saddle-shaped area on top of sphenoid bounded by ant and post clinoid processes; made up of tuberculum sellae (post to prechiasmiatic sulcus), hypophysial fossa (seat of saddle post to tuberculum sellae), dorsum sellae (protrudes superiorly to form post clinoid processes)Ant cranial fossa: frontal, ethmoid and body and lesser wings of sphenoidMiddle cranial fossa: separated from ant by sphenoidal crests of lesser wing and limbus; separated from post by sup border of petrous temporal bone; formed by greater wings of sphenoid, squamous and petrous temporal bonePost cranial fossa: ant boundary is dorsum sellae of sphenoid; temporal bone forms walls; in occipital protuberance marks where confluence of dural venous sinuses occurPneumatised bones: contain air spaces: frontal, temporal, sphenoidal, ethmoidOrbitomeatal plane: lower margin orbit and upper margin acoustic meatus on same plane

Sutures: fibrous interlocking Metopic suture is remnant of frontal sutureSynchondroses: hyaline cartilage

Foramens: ANT CRANIAL FOSSA

Foramen cecum Nasal emissary vein (only during fetal development)Cribiform foramina Olfactory nerve (I) through sieve-like cribiform plate of ethmoid on either side of crista galliAnt and post ethmoidal foramina Ant and post ethmoidal vessels

MIDDLE CRANIAL FOSSAOptic canals Optic nerve (II) and ophthalmic arteriesSuperior orbital fissure CN III, IV, VI; ophthalmic nerve (V1); ophthalmic veins

Between greater and lesser wings of sphenoid; communicates with orbitForamen rotundum Maxillary nerve (V2)Foramen ovale Mandibular nerve (V3) and accessory meningeal artery

Opens into infratemporal fossaForamen spinosum Middle meningeal artery and vein; meningeal branch of V3Foramen lacerum In carotid artery

Closed by cartilage plate in lifeGroove of greater petrosal nerve Greater petrosal nerve, petrosal branch of middle meningeal artery

POSTERIOR CRANIAL FOSSAForamen magnum Medulla, meninge, spinal cord, vertebral arteries, ant and post spinal arteries, dural veins, spinal accessory nerve (XI)Jugular foramen IJV, IX, X, XI, inf petrosal and sigmoid sinuses, meningeal branches of ascending pharyngeal and occipital arteries

Large opening between occipital and petrous part of temporal boneHypoglossal canal Hypoglossal nerve (XII)Condylar canal Emissary veinMastoid foramen Mastoid emissary vein from sigmoid sinus, meningeal branch of occipital arteryIn acoustic meatus Facial (VII) and vestibulocochlear (VIII) nerves, labyrinthine artery

OTHERSSupraorbital Supraorbital nerve and vesselsInfraorbital Infraorbital nerve and vesselsMental Mental nerve and vesselsZygomaticofacialPalatineStylomastoid Facial nerve (VII), stylomastoid artery

Landmarks:

Pterion: greater wing of sphenoid, squamous temporal, frontal and parietal; overlies course of ant division of middle meningeal arteryLambda; junction of lambod and sagittal suturesBregma: junction of coronal and sagittal suturesAsterion: junction of parietomastoid, occipitomastoid and lamboid suturesNasion: junction of frontonasal and internasal sutures

Scalp

1) Skin: many sweat and sebaceous glands and hair follicles2) Connective tissue: thick, dense, richly vascular, many cutaneous nerves3) Epicranial aponeurosis: attachment for muscle bellies (occipitofrontalis, temporoparietalis, sup

auricular – all innervated by facial nerve (VII)4) Loose areolar tissue: allows free movement of above 3 layers; pus and blood can spread easily in

this5) Pericranium: external periosteum of neurocranium

Cranial Meninges

Extradural / epidural space: space pathologically; NOT continuous with spinal epidural space

Subdural space: pathological space

2-Arachnoid mater: thin, intermediate

Subarachnoid space: contains CSF, formed by choroid plexuses

3-Pia mater: delicate, vasculated; Arachnoid and pia are continuous, make up leptomeninx

1-Dura mater: tough, thick, fibrous; external periosteal layer (adherent to int table of skull, continuous with periosteum on ex surface of skull), internal meningeal layer (continuous with spinal dura mater at foramen magnum); internal layer adherent to external except where infoldings occur

Infoldings: Cerebral falx – in longitudinal cerebral fissure, separates cerebral hemispheres, from frontal crest of frontal bone and crista galli of ethmoid internal occipital protuberanceCerebellar tentorium – separates cerebellum and cerebrum; attaches to clinoid process of sphenoid, petrous temporal bone, occipital bone and parietal bone; divides brain into supratentorial and infratentorial compartments; brainstem passes through tentorial notchCerebellar falx- attached to internal occipital crest, separates cerebellar hemispheresSellar diaphragm – between clinoid processes, roof over hypophysial fossa containing pituitary gland

Dural Venous Sinuses

Frontal emissary vein passes through foramen cecum, connects SSS with veins of frontal sinus and nasal cavities; parietal emissary passes through parietal foramen connecting SSS with veins of scalp; mastoid emissary passes through mastoid foramen connecting SS with occipital/post auricular vein; posterior condylar emissary passes through condylar canal connecting SS with suboccipital plexus

Other Vasculature

Middle meningeal artery: from maxillary; enters floor of middle cranial fossa through foramen spinosum runs laterally runs anteriorly on greater wing of sphenoid ant branch runs pterion then around vertex; post branch over post craniumMiddle meningeal vein: drains into pterygoid plexus

Brain

Spaces between periosteal and meningeal layers of duraConfluence of sinuses: where sup, straight, occipital and transverse meetArachnoid granulations: collections of arachnoid villa which protrude through meningeal layer into sinusesSup sagittal sinus: from crista galli to int occipital protuberance; receives sup cerebral veins and lateral venous lacunaeInf: runs in border of cerebral falxStraight: formed by union of inf CS and great cerebral vein; runs where cerebral falx attaches to cerebellar tentoriumTransverse x2: pass laterally along postlat margins of cerebellar tentorium; become sigmoid at post aspect of petrous temporal bones; form groove in occipital bones; DRAINS confluenceSigmoid x2: form grooves in temporal and occipital bones; continues as IJV after transversing jugular foramen

Occipital: in border of cerebellar falx; communicates with internal vertebral venous plexusSup petrosal: run in cerebellar tentorium; ends in transverse sinusInf petrosal: runs in groove between petrous part of temporal bone and basilar part of occipital bone; ends in IJVBasilar plexus: connects inf petrosal sinusesCavernous sinus: on either side of sella turcica on upper surface of sphenoid; extends from sup orbital fissure to apex of petrous part of temporal bone; receives sup and inf ophthalmic veins, sup middle cerebral vein and sphenoparietal sinus; drains through sup and inf petrosal sinuses and emissary veins to pterygoid plexus; contains int carotid artery, abducent nerve (VI), oculomotor (III), trochlear (IV), trigeminal (V)Emissary veins: connect venous sinuses with external veins; valveless; usually flows away from brain

Ventricles

Blood Supply

Cerebrum: occipital lobe separated from others by parieto-occipital sulcusDiencephalon: epithalamus, dorsal thalamus and hypothalamusMidbrain: lies at junction of middle and post cranial fossaePons: in ant part of post cranial fossaMedulla oblongata: in post cranial fossaCerebellum: 2 lateral hemispheres united by vermis

Lateral ventricles x2 interventricular foramen x2 3rd ventricle (between R+L ½’s of diencephalons cerebral aqueduct 4th ventricle (on post pons and medulla) central canal of spinal cord, enters subarachnoid space through median aperture or lat apertures x2 (ONLY means by which CSF enters SAS), enters interpeduncular and quadrigeminal cisterns then superiorly through medial and suplat surfaces. CSF secreted by choroidal epithelial cells in choroids plexuses in roof of 3rd and 4th V’s, and inf horns of lat ventricles, which are fringes of pia mater. Absorbed through arachnoid granulations into venous system. NB. Monro-Kellie doctrine – skull is rigid block, inc contents cause inc ICp. Cisterns separate arachnoid and pia: cerebellomedullary (post and lat, gains CSF from 4th ventricle), pontocerebellar (continuous with spinal SAS), interpeduncular (basal, between cerebral peduncles of midbrain), chiasmatic (antinf to optic chiasm), quadrigeminal (between corpus callosum and cerebellum, contains great cerebral vein), ambient (lat to midbrain)

In carotid artery (ant circulation of brain): arises from common carotid to cranial base enters cranial cavity through carotid canals in petrous temporal bone go ant through cavernous sinus (with III, IV, VI above it, optic nerve passes ant to it) in carotid groove in side of sphenoid split into ant and middle cerebral arteriesVertebral artery (post circulation of brain): 1st branch of 1st part subclavian artery L larger than R cervical parts ascend through transverse foramina of C1-6, atlantic parts perforate dura and arachnoid and pass through foramen magnum intracranial parts unite at pons to form basilar artery ascends to clivus through pontocerebellar cistern to sup border pons divides into post cerebral arteriesCerebral arteries: ant (medial + sup surfaces, frontal pole), middle (lat surface and temporal pole), post (inf surface, occipital bone)

Venous drainage: valveless; sup cerebral sup sagittal sinus, inf and sup middle cerebral straight, transverse and sup petrosal sinuses, great cerebral forms straight sinus, sup and inf cerebellar transverse and sigmoid

Facial Muscles

Zygomaticus major: lat aspect zygomatic bone angle of mouth (modiolus); curl lipRisorius: parotid fascia and buccal skin modiolusDepressor angularis oris: antlat base of mandible modiolusDepressor labii inferioris: platysma and antlat body of mandible skin of lower lipMentalis: body of mandible skin of chin; big sad bottom lip

Nerves of Face

Muscles develop from mesoderm in 2nd pharyngeal archesOccipitofrontalis: occipital (bony attachments, lat 2/3 sup nuchal line epicranial aponeurosis) and frontal (no bony attachments, epicranial aponeurosis skin and subcut tissue) bellies; surprisedOrbicularis oris: med maxilla and mandible, perioral skin, angle of mouth m membrane of lipsBuccinator: mandible, alveolar processes, pterygomandibular raphe (thickening of buccopharyngeal fascia) angle of mouth, orbicularis oris; deep muscles; blow out cheeksOrbicularis oculi: med orbital margin, med palpebral ligament, lacrimal bone skin of margin of orbit, sup and inf tarsal plate; palpebral (gently closes eyelids), lacrimal (pulls lids medially), and orbital part (tightly closes eyelids)Corrugator supercilli: med end superciliary arch skin sup to middle of supraorbital margin and superciliary arch; confusedProcerus: fascia aponeurosis over nasal bone and lat nasal cartilage skin of inf foreheadLevator labii superioris: infraorbital margin skin of upper lipZygomaticus minor: ant aspect zygomatic bone skin of upper lip; curl lip

Cutaneous: from cervical plexusGreat auricular nerve: inf aspect auricle, parotid region of face; Trigeminal: from lat surface of pons; sensory to face, motor to muscles of mastication (massester, temporal, medial + lateral pterygoids

Ophthalmic: sensory; enters orbit through sup orbital fissure trifurcates into frontal, nasociliary and lacrimal frontal runs in roof of orbit splits into supraorbital and supratrochlear nerves forehead and scalp nasociliary divides in orbit into post ethmoidal, ant ethmoidal (gives off ex nasal nerve) and intfatrochlear nerves lacrimal is sensory and secretomotor to lacrimal glands

Maxillary: sensory; leaves cranium through foramen rotundum in base of greater wing of sphenoid enters pterygopalatine fossa enters orbit through inf orbital fissure where it becomes inf orbital nerve zygotamic runs in lat wall of orbit gives off zygomaticofacial and zygomaticotemporal (secretomotor to lacrimal) nerves, sensation to lat cheek and temple infraorbital palatine branches, branches to mucosa of maxillary sinus, to post teeth (via sup alveolar nerves) passes through infraorbital foramen

Vasculature of Face

pterygopalatine nerves – suspend pterygopalatine ganglion in fossa; sensory to nose, palate, tonsil, gingivae

Mandibular: union of sensory and motor root in foramen ovale in greater wing of sphenoid divides into auricotemporal (to parotid gland), buccal and mental nerves

Innervation of scalp post to auricles is from spinal cutaneous nerves (greater auricular, lesser, greater and third occipital nerves). Ant to auricles from trigeminal (supratrochlear, supraorbital, zygomaticotemporal, auriculotemporal)

Motor: Facial: motor root to facial expression muscles – root around temporal bone emerges through stylomastoid foramen between mastoid and styloid processes gives off post auricular nerve (passes postsup to auricle of ear, supplies auricularis post and occipital belly of occipitofrontalis rest of facial nerve runs forward through parotid gland branches.

Temporal: from sup aspect parotid gland crosses zygotmatic arch auricularis sup and ant, frontal belly occipitofrontalis, sup orbicularis oculiZygomatic: inf orbicularis oculi and facial muscles inf to orbitBuccal: passes external to buccinator upper orbicularis oris and inf levator labii superiorisMarginal: to risorius and muscles of lower lip and chin; emerges from inf border of parotid, and crosses inf border of mandibleCervical: passes inf from inf border of parotid gland then post to mandible

2nd (pterygoid): at lat pterygoid muscle, medial to temporal muscle masseteric (TMJ and masseter) deep temporal (deep to temporal muscle, to muscle) pterygoid (to pterygoid) buccal (to buccal fat pad, buccinator, buccal mucosa)

3rd (pterygopalatine): distal to lat pterygoid, passes through pterygomaxillary fissure to pterygopalatine fossa, lies ant to pterygopalatine ganglion post sup alveolar (maxillary molar and premolar teeth) infraorbital (traverses infraorbital foramen; to IO and IR, lacrimal sac, maxillary canines and incisors, maxillary sinus, skin of face) pterygoid canal (mucosa of upper pharynx, pharyngotympanic tube, tympanic cavity) pharyngeal (nasopharynx, sphenoidal air sinus) descending palatine (hard and soft palate) sphenopalatine (nasal cavity, sinuses, anterior palate)

Scalp supplied by occipital, post auricular, superficial temporal arteries from ex carotid; in carotid Supraorbital and supratrochlear are branches of ophthalmic artery

Face and scalp mostly from ex carotid arteryFacial: from ex carotid; passes to inf border of mandible deep to platysma crosses mandible, buccinator and maxilla to med canthus of eye; deep to zygomaticus major and levator labii superioris; branches are sup and inf labial, lat nasal and angular arteriesSuperficial temporal: terminal branch of ex carotid; emerges between TMJ and auricle temporal fossa ends by dividing into frontal and parietal branchesTransverse facial: from sup temporal; superficial to masseter; supplies parotid gland, masseter and skin of faceMaxillary: split into 3 parts relative to lat pterygoid1st (mandibular): prox to lat pterygoid, runs deep to condylar process of mandible, but lat to stylomandibular ligament deep auricular (to ex acoustic meatus, ex TM, TMJ ant tympanic (in TM) middle meningeal (enters cranial cavity via foramen spinosum; to periosteium, bone, red BM, dura mater, trigeminal ganglion, gacial nerve, geniculate ganglion, tympanic cavity, tensor tympani) accessory meningeal (enters cranial cavity via foramen ovale; to infratemporal fossa, sphenoid bone, mandibular nerve, otic ganglion inf alveolar (via mandibular foramen; mandible, chin, myloyoid

Parotid Gland

Orbits

ValvelessDeep facial vein: drains into pterygoid plexus deeplyFacial vein: joins by ant communicating branch of retromandibular vein into IJVSup ophthalmic: drains into cavernous sinusRetromandibular: formed by joining of sup temporal and maxillary; runs superficial to ex carotid and deep to facial nerve; ant branch joins with facial, post branch joins post auricular to form EJV

Scalp drained by supraorbital, supratrochlear, superficial temporal and post auricular, occipital, deep temporal

LymphFrom scalp, face and neck drains into superficial ring of LN’s (submental, submandibular, parotid, mastoid, occipital) deep cervical LN’s (mainly located along IJV) jugular lymphatic trunk to join thoracic duct or BC veinLat face/scalp superficial parotid LNUpper lip + lat lower lip submandibular LNChin and central lower lip submental LN

Enclosed in tough fibrous parotid sheath, from investing layer of deep cervical fascia; wedged between ramus of mandible and mastoid process; apex at angle of mandible, base related to zygomatic arch; duct passes anteriorly from ant edge turns medially at ant border of masseter pierces buccinator enters mouth at 2nd maxillary molarFrom sup to deep in gland: parotid plexus of facial nerve, retromandibular vein, ex carotid arteryGland SUPPLIED by greater auricular (C2-3, supplies sheath), auriculotemporal (from trigeminal, secretory)

Roof: orbital frontal, lesser wing sphenoidMedial: ethmoidal, lacrimal, frontal, sphenoidsInf: maxilla, zygomatic, palatine; split from lat by inf orbital fissureApex: at optic canal in lesser wing of sphenoid, med to sup orbital fissurePalpebral conjunctiva is continuous with bulbar conjunctiva (adherent to periphery of cornea); deep recesses at sup and inf conjunctival fornices; eyelids strengthened by tense band of connective tissue (sup and inf tarsi), orbicularis oculi is superficial to this; tarsal gland lubricate eyelashes and lids, ciliary glands are assoc with eyelashes; med and lat palpebral commissures define angles of eye at med and lat canthi; medial and lat palpebral ligament connects tarsi to med margin of orbit, orbicularis oculi inserts onto med one; orbital septum extends from tarsi to margins of orbitLacrimal glands: secrete lacrimal fluid lacrimal duct in lat sup conjunctival fornix conjuctival sac lacrimal canaliculi at lacrimal punctum on lacrimal papilla near med angle eye lacrimal sac nasolacrimal duct inf nasal meatus; fluid production stimulated by paraS from facial (VII) and maxillary (V)

LR: common tendinous ring sclera; abducent (VI); look outMR: common tendinous ring sclera; oculomotor (III); look inSO: body of sphenoid through fibrous ring of trochlea sclera deep to SR; trochlear (IV); look down and outIO: ant floor of orbit sclera deep to LR; oculomotor (III); look up and outNB: medial movement of sup pole is intorsion, lat movement of sup pole is extorsion; triangular expansions from LR and MR attach to lacrimal and zygomatic bones forming check ligaments, fuse with fascia of IO and IR to form suspensory ligament of eyeball; III, IV, VI enter through sup orbital fissure

Nerves: Ciliary ganglion comes from V1 – receive branches from communicating branch of nasociliary nerve (V1), paraS/oculomotor root of ciliary ganglion (III), sym root of ciliary ganglion (int cervical plexus)

short ciliary nerve: from V1, paraS and sym fibres to ciliary body and iris long ciliary nerve: from V1, sym fibres to dilator pupillae

3 layers: Fibrous: sclera and cornea (sensory from ophthalmic V); provides attachment for muscles of eyeVascular: choroid, ciliary body, iris; vascular lamina externally, capillary lamina of choroid deeper; ciliary body attaches choroid to iris; ciliary processes are folds on internal surface of ciliary body, secrete aqueous humour; post chamber is space between iris and ciliary body; sphincter pupillae closes pupil, dilator pupillae opens pupilInner: retina; consists of neural (light detection) and pigment cell (vision) layers; optic disc contains no photoreceptors and is insensitive to light; macula lutea is lateral to optic disc, fovea centralis is central depression is macula lutea; optic part terminates at ora serrata, post to ciliary body; supplied by central artery of retina (from ophthalmic) and central vein of retina

Capsule of lens is anchored by zonular fibres to ciliary body, encircled by ciliary processes (contraction fat lens)

Aqueous humour drains into scleral venous sinus at iridiocorneal angle removed by limbal plexus drain into vorticose and ant ciliary veins

2: sup rectus 3: inf rectus 4: med rectus 5: lat rectus 6: sup oblique 8: inf oblique7: trochlea 9: levator palpebra superioris 10: sup tarsus 11: sclera 12: optic nerve

Extraocular: LPS: from lesser wing of sphenoid sup tarsus and skin; oculomotor (III); deep lamina includes sup tarsal muscleRecti muscles: arise from common tendinous ring surrounding optic canalSR: common tendinous ring sclera; oculomotor (III), look up and in; muscular sheath fused with LPS so when look up eyelid opensIR: common tendinous ring sclera; oculomotor (III), look down and in

Blood supply:

Temporal Region

Temporal fossa: post and sup by temporal lines, ant by frontal and zygomatic bones, lat by zygomatic arch, inf by infratemporal crest, floor by pterion (frontal, parietal, temporal, greater wing of sphenoid), filled by temporal muscle covered by temporal fascia (attached to sup temporal line, zygomatic arch)

Infratemporal fossa: lateral is ramus of mandible, medial is lateral pterygoid plate, ant is post aspect of maxilla, post is tympanic plate and mastoid and styloid processes, sup is inf surface of greater wing of sphenoid, inf is med pterygoid muscle attaching to mandible. Contains:Inf temporal muscle, lat and med pterygoid musclesMaxillary artery: from ex carotid, arises post to neck of mandible Pterygoid venous plexus: between temporal and pterygoid muscles; anastomosis with facial vein via deep facial vein, cavernous sinus via emissary veinMandibular nerve: descends through foramen ovale; divides into inf alveolar, auriculotemporal, lingual, buccal nerves in fossa; supplies muscles of mastication (except buccinator)Otic ganglion: inf to foramen ovale, med to V3, post to med pterygoid muscle

In carotid ophthalmic artery central artery of retina (runs in dural sheath of optic nerve, then within optic nerve, emerges in optic disc) supraorbital (passes through supraorbital foramen to scalp and forehead0 supratrochlear lacrimal (along sup border of LR to lacrimal gland, conjunctiva, eyelids) dorsal nasal (along dorsum of nose) post ciliary arteries (supply choroid (short) and ciliary body and iris (long)) post ethmoidal (ethmoid) ant ethmoidal (also supplies frontal sinus, nasal cavity, dorsum nose) ant ciliary (network in iris and ciliary body)

Ex carotid maxillary infraorbital artery

Venous drainage through sup and inf ophthalmic veins (pass through sup orbital fissure cavernous sinus), central retinal vein goes straight into cavernous sinus

TMJ

HingeCndyle of mandible, articular tubercle of temporal bone, mandibular fossaJoint capsule is looseHas sup and inf synovial membranes relative to articular disc; temporomandibular ligament prevents post dislocation; stylomandibular ligament is thickening of capsule of parotid (styloid process to angle); sphenomandibular ligament (spine of sphenoid to lingula of mandible) bears weight

Movement produced by muscles of mastication – temporal, masseter, med and lat pterygoids – all innervated by V3Temporal: from temporal fossa tip of coronoid process and ant border of ramusMasseter: from inf border of maxillary process of zygomatic bone and zygomatic arch angle and lat surface ramusLat pterygoid: 2 heads from infratemporal surface of greater wing of sphenoid, and lat surface lat pterygoid plate joint capsule and articular disc, condyloid processMed pterygoid: 2 heads from med surface lat pterygoid plate and pyramidal process of palatine bone and tuberosity of maxilla med surface ramus of mandibleSuprahyoids: digastric, stylohyoid, mylohyoid, geniohyloidInfrahyoids: omohyoid, sternohyoid, sternothyoid, thyrohyoid

Close mouth: temporal, masseter, medial pterygoidOpen mouth: lat pterygoid, and supra and infrahyoidsProtrude chin: lat and med pterygoid, masseterRetrude chin: temporal and masseterLateral: temporal of same side, pterygoids of opposite side

Oral Cavity

Oral vestibule: slit-like space between teeth and buccal gingival inc lipsOral cavity proper: between upper and lower dental arches, communicates with oropharynxLips: contain orbicularis oris and sup and inf labial muscles; labial frenula on inner surface in midline; blood from sup and inf labial arteries (from facial, infraorbital and mental); sup lip supplied by infraorbital nerve, lower by mental nerveCheeks: prominence occurs at junction of zygomatic and buccal regions; buccinators and buccal fat pads; supplied by buccal branches of maxillary artery and mandibular nerveGingivae: composed of fibrous tissue covered with mmTeeth: deciduous (20) then permanent (32); 2x incisors, 1x canine, 2x premolars, 3x molars; vestibular inward, lingual outward; crown projects from gum, neck between crown and root, root held in socket by peridontium; made of dentin, covered by enamel at crown and cement at root; root canal transmits nerves and vessels to pulp cavity through apical foramen; tooth sockets are in alveolar proceses, separated by

intraalveolar septa; roots of teeth and bone of alveolus form dento-alveolar syndesmosis, peridontium extends between cement of root and periosteum of alveolus; supplied by sup and inf alveolar branches of maxillary artery; lymph to submandibular LN’s; sup (V2) and inf (V3) alveolar nerves form dental plexuses

Palate: Hard (ant 2/3 have bony skeleton formed by palatine processes of maxillae and horizontal plates of palatine bones; nasopalatine nerves pass from nose though incisive canals into incisive fossa behind incisors in midline, ant to fossa is elevation called incisive papilla; greater palatine foramen opens medial to 3rd molar, contains greater palatine vessels and nerve (branch of V2); lesser palatine foramen is post to greater in palatine bone, contains lesser palatine vessels and nerve (branch of V2))Soft (post 1/3, palatine aponeurosis from tensor veli palatine muscle attaches to post aspect of hard palate; other muscles are levator veli palatine, palatoglossus, palatopharyngeus, musculus uvulae; conical uvula hangs from it; joined by palatoglossal and palatopharyngeal arches to tongue and pharynx (these are the pillars of fauces, glossal anterior, pharyngeal posterior); palatine tonsils found on either side of oropharynx, in tonsillar fossa between 2 arches); palatine glands are found deep to muscosa; palatine raphe is line passing in midlineVenous drainage via pterygoid plexus; soft palate also supplied by nasopalatine nerve (V2); muscles are supplied by pharyngeal plexus, except tensor veli palatine supplied by V2

Artery: lingual (from ex carotid, dorsal to post, deep to ant, passes deep to hyoglossus, dorsal communicate, deep don’t 2y to septum)Veins: dorsal and deep lingual veins sublingual veinLymph: post 1/3 sup deep cervical LN; med ant 2/3 inf deep cervical LN; lat ant 2/3 submandibular LN; apec and frenulum submental LN

Salivary glands: submandibular (along body of mandible partly deep to mylohyoid; duct passes medially, lingual nerve loops under it, opens into sublingual papilla @ base of frenulum; supplied by submental arteries, paraS from lingualr nerve via shorda tympani nerve, sym from sup cervical ganglion; lymph to deep cervical LN); sublingual (in floor between genioglossus and mandible, glands unite around lingual frenulum; numerous ducts open among sublingual folds; blood from sublingual and submental arteries from lingual and facial arteries; same nerves as submandibular); parotid see above

Pterygopalatine Fossa

Between pterygoid process of sphenoid and post aspect of maxilla, med is perpendicular plate of palatine bone, roof is greater wing of sphenoid, floor is pyramidal process of palatine bone; communicates with

Tongue: root rests on floor of mouth = post 1/3; body = ant 2/3; dorsum has v-shaped terminal sulcus pointing posteriorly to foramen cecum, divides tongue into ant and post parts; vallate papillae (ant to sulcus in v-shaped row), filiform papillae (sensitive to touch, ant tongue), fungiform papillae (at apex), foliate (at margins); has midline groove; post tongue has underlying lymphoid nodules (make up lingual tonsil); deep lingual vein visible on either side of frenulum along with sublingual caruncle (opening of submandibular salivary gland); muscles separated by lingual septumExtrinsic muscles: alter position; genioglossus (sup mental spine of mandible dorsum of tongue), hyloglossus (body and greater horn of hyoid inflat tongue), styloglossus (ant distal styloid process, stylohyoid lig postlat tongue), palatoglossus (palatine aponeurosis of soft palate postlat tongue)Intrinsic muscles: alter shape; sup + inf longitudinal, transverse, vertical; confined to tongue with no attachment to boneInnervated by motor: hypoglossal (XII) (except palatoglossus, from pharyngeal plexus); sensory: lingual (V3) ant 2/3, post by lingual branch of glossopharyngeal (IX); taste: chordae tympanii nerve (VII) ant 2/3, post by lingual branch of glossopharyngeal (IX); small area just ant to epiglottis supplied by int laryngeal nerve (X); sensory fibre carry paraS nerves to glands of tongueSweetness @ apex, saltiness lat, sour and bitter post

infratemporal fossa through pterygomaxillary fissure, with nasal cavity via sphenopalatine foramen, with orbit via inf orbital fissure, with middle cranial fossa via foramen rotundum and pterygoid canal; contains terminal part of maxillary artery, maxillary nerve

Nose

Supporting skeleton made by bone (nasal bones, frontal processes of maxilla, nasal part of frontal, bony parts of nasal septum) and hyaline cartilage (2 lat cartilages, 2 alar cartilages, 1 septal cartilage); septum partly bony and cartilage (perpendicular plate of ethmoid, descends from cribiform plate; vomer, postinf part; septal cartilage, articulates with bone); roof = frontal, nasal, ethmoid, sphenoids bones; floor = palatine process of maxilla, horizontal plates of palatine bone; medial = nasal septum; lateral = nasal conchae; nasal vestibule is lined with skin, otherwise lines with mucosa; inf 2/3 of mucosa is respiratory, upper 1/3 is olfactory; conchae separated by meatus which lie inf to related conchae; sup meatus received post ethmoidal sinus, middle meatus has ethmoidal infundibulum where receives frontal sinus via frontonasal duct; inf meatus receives nasolacrimal duct; postsup is sphenoethmoidal recess (receives opening of sphenoid sinus), medially is common nasal meatusArtery: Med/lat wall: ophthalmic ant and post ethmoidal

Maxillary sphenopalatine (through spenopalatine foramen), greater palatine (through incisive canal)

Facial septal branch of sup labial Submucosal venous plecus drains into sphenopalatine, facial and ophthalmic veins; ex nose drains into facial vein via angular and lat nasal veinsPostinf = maxillary via nasopalatine to septum, via greater palatine nerve to lat wall; antsup = ophthalmic nerve via ant and post ethmoidal nerves; ext nose = V1 (via infratrochlear and ex nasal branch of ant ethmoidal nerve), alae by nasal branch of infraorbital nerve (V2)Olfactory nerves pass through cribiform plate olfactory bulb

Monday thur 7.30 – 9.30

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cashmere clubbottom of columbo ston lpast beckenham library