Lips- Surround the mouth, or entrance to the oral cavity.- Separated from the cheek by nasolabial groove.- Philtrum extends superiorly from at the columnella, the fleshy partition between the nostrils to the vermillion border inferiorly
- Lower lip is separated from the chin by the labiomental groove.- Upper and lower lip meets at the angle of the mouth.
Layers of the Lips:1. Skin - thin and hairless, allowing the redness of the underlying capillary bed to show through.2. Superficial Fascia - loosely arranged and contains some fats.3. Muscle - orbicularis oris
3. Submucous Tissue - contains blood vessels and labial mucous glands which opens to the vestibule of the mouth.4. Mucous membrane - coats the intraoral vestibule of the lips and then reflects from the upper and lower lips to the attached gingiva. This is called the vestibular or mucolabial fold.
External Ear- Contains a single elastic cartilage which provides support to the external ear.- Skin is tightly bound to the cartilage with no intervening subcutaneous layer.- Skin and cartilage is thrown into several folds.
Cheeks (Buccae):- Form the lateral movable walls of the oral cavity.- Mucosa of the cheeks ends in the mucobuccal fold superiorly and inferiorly.- Buccal fat pad is lies superficial to the buccinator muscle.- Parotid duct opens intraorally thru the mucosa of the cheeks at the occlusal level of the second maxillary molar.
Layers of the Cheeks:1. Skin,2. Superficial fascia containing the fat of Bichot, zygomatic major, risorius, platysma, the parotid duct, and the branches of the facial and trigeminal nerves.3. Muscular layer – Buccinator muscle4. Submucous layer containing mucous buccal glands,5. Mucous membrane
External Nose- The framework is composed of the nasal bones, septal cartilage, lateral cartilages, and alar cartilages.- Skin of the nose is continues beyond the external nares into the vestibule of the nose, with nasal hairs to filter larger particles of dusts in the air.
Eyelids (Palpebrae) Form a curtain for the ocular globe or the eyeball.External features:1. Palpebral fissure - transverse eliptical opening between the upper and lower eyelid.2. Palpebral commissure - the lateral and medial junctions of the upper and lower eyelids.3. Superior palpebral margins - covers the superior 1/5s of the iris when the lids are open.
4. Inferior palpebral margins - cuts across the lower border of the iris when the lids are open.5. Cilia or eyelashes - project from the palpebral margins intwo or three irregular rows.6. Plica semilunaris - a cresent fold at the medial angle of the eye that separates the white of the eye from the medial, reddish-colored lacrimal lake.
External features:7. Lacrimal lake - small, raised, triangular are bordered by the plica semilunaris; a raised, reddish area within the lake is the caruncle.8. Superior and inferior papillae - are small, raised bumps at the junction of the ciliated hairless margins of the lids; at the apex of which is the lacrimal punctum.9. Conjuctivum - mucous membrane inner lining of the lid.
The Five Layers of the ScalpSkin a layer of thin skin containing numerous hair follicles, sweat glands, and sebaceous glandsConnective tissueA thick, dense, subcutaneous connective tissue is anchored firmly to the skin above and the membranous layer below.
AponeurosisIs formed by the galea aponeurotica.Loose Connective TissueAllows freedom of movement of the superficial three layers over the top of the skullPeriosteumFirmly anchored to the underlying bone.
1. Craniofacial muscles- related mainly to theorbital margins andeyelids, the externalnose and nostrils, thelips, the cheeks andmouth, the pinna, scalp,and cervical skin. Theseare collectively referredto as the muscles offacial expression.
Common Characteristics of the Muscles of Facial Expression• All are inserted into the skin of the face;• All are supplied by the muscular branches of the facial nerve
2. Masticatory muscles- - concerned primarily with the movements of the temporomandibular joint.
The Craniofacial Muscles• They are grouped as: 1. epicranial 2. circumorbital and palpebral 3. nasal 4. buccolabial
1. The Epicranial MusclesThe epicranius is made up of two main parts:1. Occipitofrontalis2. Temporo-parietalis
The Muscles of the Scalp Muscle Origin Insertion Action Cranial NerveFrontalis Aponuerosis Skin of the Pulls the VII – of the scalp forehead scalp up and temporal back branchesOccipitalis Lateral 2/3s Skin of the Pulls the VII – of the occipital scalp posterior superior area backward auricular nuchal line, and forward branches mastoid process
2. Circumorbital and Palpebral MusclesThis group of muscle if composed of the following: 1. orbicularis oculi, 2. corrugator supercilii, 3. and levator palpebrae superioris.
Muscle Origin Insertion Action Cranial NerveOrbital part Bone of the Medial Closes eyes VII – upper medial palpebral forcefully temporal orbital ligament and margin zyomatic branchesPalpebral Medial Fibers arch Closes the VII –part palpebral laterally thru eye gently temporal ligament lids and and interdigitate zyomatic laterally in a branches rapheLacrimal Lacrimal Medial Squeezes VII –part bone behind aspects of lubricating temporal the lacrimal the lid tears against and sac the eyeball zyomatic branches
Muscle Origin Insertion Action Cranial NerveCorrugator Medial Skin Vertical VII -supercilii aspect of the underlying wrinkling of temporal supraorbital the eyebrow the bridge of branches margin the nose as in frowning
3. Nasal MusclesThe nasal muscle group is composed of the following muscles:1. Procerus2. Nasalis - compressor nares - dilator nares3. Depressor septi
Muscle Origin Insertion Action Cranial NerveDepressor Medial fibers Mobile part Draw the VII –septi of dilator of the nasal septum Superior naris muscle septum downwards buccal to narrow the branches nostrils
Muscle Origin Insertion Action Cranial NerveProcerus Nasal bone Skin of Transverse VII – and lateral glabella wrinkling of Temporal nasal the bridge of and cartilages the nose zygomatic branchesNasalisCompressor Canine Midline Compresses VII –Nares eminence of aponeurosis the nostrils Zygomatic the maxilla overlying and buccal nasal branches cartilagesDilator Nares Nasal notch Skin of Dilates or VII – of the margin of flares the Zygomatic maxilla nostril nostrils and buccal branches
4. Buccolabial MusclesI. Elevators, retractors, and evertors of the upper lipII. Depressors, retractors, and evertors of the lower lipIII. A compound sphincter
I. elevators, retractors, and evertors of the upper lip :levator labii superioris alaque nasi,levator labii superioris,zygomaticus major and minor,levator anguli oris,and risorius
II. Depressors, retr actors, and evertors of the lower lipdepressor labii inferioris,depressor anguli oris, andmentalis
III. A compound sphincter orbicularis oris, accessory muscles to the orbicularis oris incisivus superior, and incisivus inferior
Muscle Origin Insertion Action Cranial NerveLevator labii Frontal One slip goes Elevate the VII –superioris process of the to the ala of ala of the zygomatic andalaque nasi maxilla the nose the nose and the buccal other to the upper lip branches orbicularis orisZygomaticus Zygomatic Angle of the Draws the VII –major bone mouth angle of the zygomatic and mouth up and buccal back as in branches smiling or laughingZygomaticus Zygomatic Skin on the Deepen the VII –minor bone medial nasolabial nasolbial zygomatic and to the groove groove as in buccal zygomaticus sorrow branches major muscle
Muscle Origin Insertion Action Cranial NerveLevator labii 3 heads:superioris Angular Alar Elevates the VII - head: frontal cartilacge upper lip zygomatic process of and skin of and flares and buccal the maxilla the nose the nostrils branches Infraorbital head: Upper lip Gives the inferior expression margin of of sadness the orbit Zygomatic Contraction head: Nasolabial groove and of the whole zygomatic muscle gives bone upper lip the expression of disdain or doubt
Muscle Origin Insertion Action Cranial NerveLevator Canine fossa Angle of the Elevates the VII –anguli oris of the mouth angle of the zygomaticor caninus maxilla mouth and buccal below the (muscle of branches infraorbital happiness) foramenMentalis Incissive Skin of the Elevate the VII – fossa of the chin chin. It also mandibular mandible causes branches trembling of the chin. It wrinkles the skin of the chin as in disdain or doubt.
Muscle Origin Insertion Action Cranial NerveRisorius Superficial Skin and Draw the VII – fascia over mucosa of anglef the zygomatic the parotid the angle of mouth and buccal fascia the mouth laterally, branches giving an expression of strain or tensenessDepressor Oblique line Lower lip Depresses VII –labii of the the lower lip mandibularinferioris mandible as in “irony” branchesDepressor Oblique line Angle of the Depresses VII – buccalanguli oris of the mouth the angle of andor mandible the mouth mandibularTriangularis branches
Muscle Origin Insertion Action Cranial NerveBuccinator Pterygmandi The fibers Draw the VII - buccalOr Bugler’s bular raphe, are directed angle of the branchesor buccal towards the mouthTrumpeter’s alveolar angle of the laterally andmuscle processes of mouth to press the maxilla and blending cheeks mandible with he against the upper or teeth while lower chewing. portions of Useful in the mastication, orbicularis swallowing, oris muscle whistling, sucking, and blowing
Muscle Origin Insertion Action Cranial NerveOrbicularis Extrinsic Pass around Compresses VII -oris fibers: the mouth the lips zygomatic, From within the against the buccal and insertions of lips as a anterior mandibular circumoral sphincter teeth, closes branches muscles the mouth, and protrudes Intrinsic Pass the lips fibers: obliquely From the forward and incisive insert into fossae of the the skin of mandible the lip and maxilla
Muscle Origin Insertion Action Cranial NervePlatysma Skin and The fibers Retract and VII --thin, sub- superficial are directed depress the cervicalcutaneous fascia of the upward and angle of the branchquadrilateral pectoral and forward to mouthmuscular deltoid be insertedsheet regions into thecovering the lower borderupper part of theof the chest, mandibleside of theneck andlower part ofthe face
Muscles of the External Ear Muscle Origin Insertion Action Cranial NerveAnterior Aponeurosis Anterior Pulls the ear VII -auricular of the scalp, medial forward temporal temporal aspect of the branches fascia helix of the auriclePosterior Superior Inferior Pulls the ear VII -auricular lateral medial backward Posterior aspect of aspect of auricular mastoid auricle branches processSuperior Aponeurosis Superior Pulls ear VII -auricular of the scalp, medial superiorly temporal temporal aspect of branches fascia auricle
The facial nerve arises as two distinct trunks from the lower border of the pons:1. the smaller of thetwo trunks is thenervus intermedius ( asensoryand parasympatheticroot)2. the larger root is themotor root
The Course of the Facial NerveFrom the lower border of the pons varolli, the two roots of the facial nerve approach and enter the internal acoustic meatus. The meatus leads to the petrous temporal bone and joins the facial canal. The facial nerve runs laterally within the facial canal, turns sharply at the genu (knee) to run posteriorly, and then drops inferiorly to exit thru the stylomastoid foramen at the base of the skull. The nerve enters the substance of the parotid gland and then breaks up into 5 sets of muscular branches. The genu of the nerve contains the sensory geniculate ganglion.
Schematic Diagram Pons varolii internal auditory meatus petrous temporal facial canal genu to run posteriorly stylomastoid foramen parotid gland five muscular branches.
Branches of the Facial Nerve1. The greater petrosal nerve2. The nerve to the stapedius muscle3. The chorda tympani nerve4. The posterior auricular nerve5. The facial branches (motor)
Branches of the Facial Nerve1. The greater petrosal nerve- arises from the genu of the facial nerve within the facial canal.- contains mainly taste fibers to the palatal mucosa and- parasympathetic fibers to the lacrimal gland, the mucosa of the palate, nasopharynx and the nasal cavity.
Branches of the Facial Nerve2. The nerve to the stapedius muscle- arises within the facial canal and is motor to the stapedius muscle of the middle ear.
Branches of the Facial Nerve3. The chorda tympani nerve - arises from the descending portion of the facial nerve within the facial canal. - leaves the skull thru the petrotympanic fissure - Taste fibers are distributed to the anterior two thirds of the tongue via the lingual nerve.
Branches of the Facial Nerve4. The posterior auricular nerve arises from the stylomastoid foramen and communicates with the great auricular and lesser occipital nerves. It has 2 branches: 1. auricular branch which supplies the auricularis posterior and intrinsic muscles on the cranial aspect of the auricle, and 2. occipital branch which supplies the occipital belly of the occipitofrontalis.
Branches of the Facial Nerve5. Facial branches (motor) arise within the parotid gland as five main groups. These are: a. Temporal b. Zygomatic c. Buccal d. Mandibular, and e. Cervical These branches innervate the muscles of facial expression and platysma.
Motor Branches of the Facial Nerve1. Temporal2. Zygomatic3. Buccal4. Mandibular5. Cervical
Motor Branches of the Facial Nerve1. Temporal2. Zygomatic3. Buccal4. Mandibular5. Cervical
Motor Branches of the Facial Nerve1. Temporal branches - travel superiorly and anteriorly to supply the facial muscles situated above the zygomatic arch, including the orbit and the forehead. They innervate: 1. the anterior and superior auricular muscles, 2. the frontalis muscle, and 3. the superior portion of the orbicularis oculis muscle.
Motor Branches of the Facial Nerve2. Zygomatic branches - runs transversely across the face to supply the facial muscles in the zygomatic, orbital, and infraorbital areas. They supply: 1. the inferior portion of the orbicularis oculis muscle, 2. the superior portions of the zygomaticus major, levator labii superioris, levator anguli oris, nasalis, and orbicularis oris muscles.
Motor Branches of the Facial Nerve3. Buccal branches - supplies the muscles of the cheek and circumoral muscles. They innervate: 1. the buccinator, and 2. the inferior portions of the zygomaticus major, levator labii superioris, levator anguli oris, nasalis, and orbicularis oris muscles.
Motor Branches of the Facial Nerve4. Mandibular branches - supplies the muscles of the chin and the lower lip. Specifically they pass to: 1. the depressor anguli oris, 2. depressor labii inferioris, and to 3. the mentalis muscles.
Motor Branches of the Facial Nerve5. Cervical branches - descend to the neck to supply: 1. the platysma, 2. posterior belly of the digastric, 3. stylohyoid muscles
Cranial Nerve TestLesions of the facial nerve may cause: (1) paralysis of facial muscles, (2) loss of taste sensation from the anterior two thirds of the tongue, (3) decreased salivation.