SCALP

P.Ravishankar Senior Lecturer Dept.of Anatomy SRM Dental College Chennai India SCALP

• Definition • Extent • Layers • supply • Blood supply • Clinical Anatomy • Definition:- covering the cranial vault

• Extent:- Anteriorly:- Supra orbital margin Posteriorly:-External occipital protuberance & Superior nuchal line Laterally:-Superior temporal line Layers of SCALP

Skin Aponeurosis Loose areolar tissue Pericranium

1. Skin

Thick and hair bearing and contains numerous sebaceous glands 2. Superficial

• Dense fibro- fatty connective tissue. • Firmly attached to the skin and the aponeurosis. • Numerous arteries, veins and . • Free anastomosis between the ICA an ECA branches.

3. (Galea Aponeuritica)

• A thin tendinous sheet that unites the occipital and frontal bellies of the occipitofrontalis muscle.

• The subaponeurotic space: potantial space beneath the aponeurosis.

4.Loose areolar tissue Extension • Anteriorly:- Eyelids • Posteriorly:- Highest and superior nuchal line • Laterally:- Superior temporal line • Dangerous area of scalp connect the superficial veins of the scalp with the diploic veins of the skull and with intracranial venous sinuses

Pericranium

• Modified periosteum • Loosely attached to bones but firmly attached to sutures

Nerve supply to scalp In front of auricle Behind the auricle Sensory Sensory • Supratrochelar br.of Frontal • Posterior division of great nerve auricular nerve from cervical plexus(C2,C3) • Supraorbital br. of frontal • Lesser occipital nerve from nerve cervical plexus(C2) • Zygomatiotemporal br.of • Greater occipital Zygomatic nerve nerve(C2dorsal ramus) • Auriculotemporal nerve,br.of • Third occipital nerve(C3 Mandibular nerve dorsal ramus) Motor Motor • Temporal br. Of Facial nerve • Posterior auricular br.of facial nerve

Blood supply to scalp

Front of auricle • Supratrochelar vessels • Supraorbital vessels • Superficial temporal vessels Behind the auricle • Posterior auricular vessels • Occipital vessels Clinical anatomy • Surgical layers of scalp:-first 3 layers of scalp

• Sebaceous cyst are common in skin layer

• The wounds of scalp don’t gape unless it is cut transversely – because the aponeurotic layer is tightly attached in the anteroposterior direction of occipitio- Clinical anatomy Black eye:- • Black discoloration of skin around eye • Blood and fluid collection in the upper eye lid • Blood accumulate to upper eyelid due attachment of frontalis muscle

Black eye Safety-valve hematoma:- • Fracture of cranial vault in children may associate with tearing of duramater and pericranium,in such cases blood from intracranial hemorrahage communicate with subaponeurotic space of scalp through the fracture line • The sign of cerebral compression doesn’t occurs until subaponeurotic space is filled • Therefore blood collection in the fourth layer is called safety –valve hematoma Dangerous layer of scalp

• Blood and pus freely tend to collect in this layer ,if pus collects in this layer the infection may travel readily along the emissary veins into the intracranial venous sinuses. • Cephalhematoma:- Subperiosteal collection of blood

• Caput succedaneum:- Subcutaneous edema .it takes place during the passage of head through the birth canal due interference of venous return