6. head face

HEAD: CRANIUM(SCALP) AND FACE

THE HEAD

BOUNDARIES Lower border of mandible Angle of mandible Mastoid process Superior nuchal line External occipital protuberance

DIVISION Face Cranium(Supraorbital margin,

Zygomatic arch, Superior border of External acoustic meatus, Mastoid process)

THE CRANIAL PART

THE CRANIUM DIVISION THE VERTEX(CALVARIA)

Frontoparietoccipital regionTemporal region

BASE OF CRANIUM(BASE OF SKULL)

Internal surfaceExternal surface

CAVITY OF CRANIUM(CRANIAL CAVITY)BrainMeninges and blood vesselsCranial nerves

FRONTAL PARIETAL OCCIPITAL REGION

Boundaries Anterior －

supraorbital margin Posterior － external

occipital protuberance and superior nuchal line

Lateral － superior temporal line

SCALP

Soft tissue covering the cranial vault It is hair bearing area of the skull Extend from supra orbital margin anteriorly

to external occipital protuberance & superior nuchal line posteriorly

On each side to superior temporal line

SCALP S-Skin C-connective tissue (superficial fascia) A-aponeurosis (galea aponeurotica)/

Occipitofrontalis L-loose areolar tissue P-pericranium

SKIN Thick and hairy Firmly attached to the epicranial aponeurosis

through dense fascia Abundance sebaceous glands Sebaceous cyst are common

CONNECTIVE TISSUE Fibrous and dense containing blood vessels and

nerves Binds skin to subjacent aponeurosis Wounds bleed profusely as blood vessels are

prevented from retraction by fibrous tissue. Bleeding is stopped by applying pressure against the bone

Subcutaneous hemorrhage are not extensive since fascia is dense

Inflammation cause little swelling but are much painful

APONEUROSIS Anteriorly frontal belly and

posteriorly occipital belly of occipitofrontalis muscle

Frontal belly originate from skin of forehead and mingled with orbicularis oculi muscle

Occipital belly originate from lateral 2/3 of superior nuchal line

It gaps if cut transversely and should be stitched

LOOSE AREOLAR TISSUE

Extends anteriorly into the eyelids because frontalis has no bony attachment

Posteriorly to superior nuchal line On each side to superior temporal line Bleeding cause generalized swelling of scalp Called dangerous layer of scalp-emissary veins

open here and carry any infections inside the brain (venous sinus)

Bleeding lead to black eye Caput succedaneum in new born

PERICRANIUM

Is the periosteum of skull Loosely attached to surface of bone but is

firmly adherent to the sutures Injury deep to it take the shape of bone

(cephalhaematoma) Scalping injury- should be replaced and

stitched because healing is better

Caput succedaneum cephalhaematoma

TEMPORAL REGION

Boundaries Superior － superior

temporal line Inferior － superior

border of zygomatic arch

Anterior － the junction of frontal and zygomatic bones

Posterior － posterior portion of superior temporal line

TEMPORAL REGION

Layers consists of five layers:

Skin Superficial fascia Temporal fascia Temporalis Periosteum

BLOOD SUPPLY

Arteries Supratrochlear Supraorbital Superficial temporal Posterior auricular

artery Occipital artery

Veins-follows the artery

NERVE SUPPLY In front of auricle

Supratrochlear n. Supraorbital n. Zygomaticotemporal n. Auriculotemporal n. Temporal branch of

facial n. Behind auricle

Greater auricular n Lesser occipital n. Greater occipital n. Third occipital n. Post. Auricular branch of

facial n.

LYMPHATICS Anterior part

Preauricular (parotid) gr. of lymph node Posterior part

Posterior (mastoid) gr. of lymph node &occipital gr. of lymph node

FACE

Boundaries Extends superiorly to the hair line, inferiorly

to the chin and base of mandible, and on each side to auricle

Forehead is common to both scalp and face

SKIN Very vascular Due to rich vascularity face blush and

blanch Wounds of face bleed profusely but heal

rapidly Results of plastic surgery are excellent on

face Facial skin is rich in sebaceous gland and

sweat gland Sebaceous gland keep the skin oily but

also cause acne in adult Sweat gland regulate body temperature

FACIAL MUSCLE Called muscle of facial expression and

lie in superficial fascia Embryologically they develop from

mesoderm of 2nd branchial arch, therefore supplied by facial nerve

ORBICULARIS OCULI

3 parts- Orbital part

Originate from medial part of medial palpebral ligament and form concentric rings, return to point of origin

Action –closes the lids tightly Palpebral part

Originate from lateral part of medial palpebral ligament Insert into lateral palpebral raphe

Action-closes the lids gently Lacrimal part

Originate from lacrimal fascia& lacrimal bone Insert into upper &lower tarsi

Action-dilate lacrimal sac

ORBICULARIS ORIS

Originate from maxilla above incisor teeth and insert into skin of lip.

Action –closes the mouth

BUCCINATOR Upper fibers

Origin- from maxilla opposite molar teeth

Insertion-upper lip Lower fibers

Origin-from mandible opposite molar teeth

Insertion-lower lip Middle fibers

Origin –from pterigomandibular raphe

Insertion-decussate before passing to lips

Action- prevent accumulation of food in vestibule of mouth

PLATYSMA Origin– upper part of

pectoral and deltoid fascia

Insertion– base of mandible, skin of lower face and lip

Action– releases pressure of skin on the subjacent veins, depress mandible, pulls angle of mouth downwards

MASTICATORY MUSCLES Masseter

Origin － inferior border and medial surface of zygomatic arch

Insertion － lateral surface of ramus of mandible and angle of mandible

Action － elevates mandible

Temporalis Origin － temporal

fossa Insertion － coronoid

process of mandible Action － elevates and

retracts mandible lateral pterygoid Medial pterygoid

NERVE SUPPLY OF FACE

Motor supply Facial nerve\

Leaves skull through internal acoustic meatus, facial canal and stylomastoid foramen

Divided three parts First part － between

stylomastoid foramen and parotid gland

Second part － within parotid gland

Third part － outside of parotid gland

SENSORY SUPPLY TRIGEMINAL NERVE Ophthalmic division

Supratrochlear Supraorbital Lacrimal Infratrochlear External nasal

Maxillary nerve Infraorbital Zygomaticofacial and

zygomaticotemporal Mandibular nerve

Auriculotemporal Buccal nerve Mental

Skin over the mandibular angle is supplied by ant. Div. Of greater auricular n.

BLOOD SUPPLY OF FACE

Arterial supply- Facial artery Superficial temporal

artery Ophthalmic artery

Supraorbital and Supratrochlear

VENOUS DRAINAGE Vein follow the arteries

and drain into common facial vein and retromandibular vein

Deep connections of facial vein-

Communication between supraorbital &superior ophthalmic vein

With pterigoid plexus of vein through deep facial vein.

Superior ophthalmic vein & ptergoid plexus of vein communicate with cavernous sinus

LYMPHATIC DRAINAGE 3 territories- Upper territories- greater

part of forehead, lateral ½ of eye lid, conjunctiva, lateral part of cheek and parotid area– preauricular lymph node (parotid)

Middle territories- median part of forehead, external nose, upper lip, lateral part of lower lip, medial ½ of eye lid, medial part of cheek, greater part of lower jaw– submandibular lymph node

Lower territories- central part of lower lip, chin– sub mental lymph node

APPLIED

Trigeminal neuralgia Maxillary and mandibular nerve are involved Excruciating pain in the region of distribution of

these nerve In infranuclear lesions of facial nerve (eg,

bell’s palsy)- whole face is paralyzed c/f

Affected side is motionless Loss of wrinkles Eye cannot be closed In smiling the mouth is drawn to normal side During mastication food accumulates in vestibule of

mouth In supranuclear lesions of facial nerve only

the lower part of face is paralyzed. The upper part (frontalis &part of orbicularis oculi) escapes due to its bilateral innervation

Dangerous area of face- infections from face mainly from upper lip & nose can go to cavernous sinus through ophthalmic vein and deep facial vein