5 The skin of face is very thin and connected to the facial bones by loose connective tissue. There is no deep fascia.The facial muscles lie in this connective tissue.
6 Arteries of head Facial artery Branch of external carotid artery. Loops around mandible (where it is palpable), at anterior border of masseter, to enter the faceFollows a tortuous course to medial angle of eyeLies deep to most facial muscles
7 Superficial temporal artery Terminal branch of external carotid artery.Ascends in front of ear (where it is palpable) to supply temporal and anterior portion of scalpTransverse facial artery runs above parotid duct to supply the cheek region
8 Maxillary artery Branch of external carotid . Enters into infratemporal fossa medial to neck of mandibleBranchesInferior alveolar a.Middle meningeal a.enters the skull through foramen spinosumSupplies cranium and dura materPosterior superior alveolar a.
9 Veins of head Facial vein Begins at medial angle of eye (angular vein) Runs downward and backward through the face, posterior to the facial arteryBelow angle of mandible, joins anterior branch of retromandibular vein to form common facial vein, which drains into internal jugular veinConnections with cavernous sinus through the ophthalmic vein.
10 Retromandibular veinFormed by union of superficial temporal and maxillary veinsDivides into an anterior branch that unites with facial vein and a posterior branch that joins posterior auricular vein to become external jugular vein
11 “Dangerous area” －lies between root of nose and two angles of mouth; in this area the facial vein has no valves
12 Nerves of headFacial nerve (Ⅶ) Leaves skull through internal acoustic meatus, facial canal and comes out through the stylomastoid foramen
13 Enters parotid gland and divides into its five terminal branches for muscles of facial expression TemporalZygomaticBuccalMarginal mandibularCervical
14 Trigeminal nerve (Ⅴ) Ophthalmic nerve (V1) Maxillary nerve (V 2) Mandibular nerve (V 3)Supplies sensory innervation to the face.
15 SCALP Boundaries Anterior－supraorbital margin Posterior－external occipital protuberance and superior nuchal lineLateral－superior temporal line
16 Layers consists of five layers: SkinSuperficial fasciaGalea aponeurotica and occipitofrontalisSubaponeurotic space (loose connective tissue)PericraniumThe superficial 3 layer are closely knit together, called scalp
17 The skin has the greatest concentration of hair and sebaceous glands The superficial fascia is dense connective tissue that binds the skin strongly to the underlying galea aponeuroticaIt is richly supplied by blood vessels.Wounds of the scalp bleed profusely but heal well.
18 Galea aponeuroticaIt is interposed between the frontalis and occipitalis portions of the occipitofrontalis muscle.These muscles place the aponeurosis under tension so that deep transverse lacerations of the scalp gape widely .
19 Subaponeurotic space (loose connective tissue) Extracranial hematoma, the result of bleeding in the subaponeurotic space, can extend over the cranium. lt can extend posteriorly, to the superior nuchal line; anteriorly, into the eyelids to produce the “black eye”; and laterally, to the temporal line.
20 Contains a rich network of deep arteries and veins Contains a rich network of deep arteries and veins. Therefore, this layer has been called the “dangerous area”.Infection may spread to the substance of the bones, to venous channels within the cranial cavity, or to the brain.
21 PericraniumFuses firmly with bone at the sutures and with the periosteum of the adjacent bone, thus limiting the sub periosteal space.