The Scalp 312021 1 THE SCALP The soft

The Scalp 3/1/2021 1

THE SCALP: The soft tissue covering the cranial vault is called the scalp Extent: Anteriorly: Supraorbital margins Posteriorly: External occipital protuberance On each side: Zygomatic arch 3/1/2021 2

Scalp consists of five layers: ü Skin ü Close network of subcutaneous tissue ü Aponeurosis ( galea aponeurotica) ü Loose subaponeurotic tissue ü Pericranium 3/1/2021 3

1. Skin: It is provided with numerous hair and sebaceous and sweat glands skin Subcutaneous tissue Galea aponeurotica Loose subaponeurotic tissue Pericranium 3/1/2021 4

2. Close network of subcutaneous tissue: It consists of close network of subcutaneous tissue which connects the skin with underlying galea aponeurotica and epicranius muscles skin Subcutaneous tissue Galea aponeurotica Loose subaponeurotic tissue Pericranium 3/1/2021 5

3. Epicranius muscle and its aponeurosis: The Epicranius includes: Occipito-frontalis muscle which consists of Ø Occipital belly behind Ø Frontal belly in front 3/1/2021 6

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Galea aponeurotica: It is a fibrous sheet which connects occipitalis and frontalis muscle 3/1/2021 8

4. Loose subaponeurotic tissue: It lies beneath the epicranius muscle and presents a potential space containing emissary veins skin Subcutaneous tissue Galea aponeurotica Loose subaponeurotic tissue Pericranium 3/1/2021 9

5. Pericranium: It is outer periosteum of the skull skin Subcutaneous tissue Galea aponeurotica Loose subaponeurotic tissue Pericranium 3/1/2021 10

Nerve supply: Ten nerves supply the scalp on each side Five in front of the auricle Four are sensory and one is motor Five behind the auricle – Four are sensory and one is motor 3/1/2021 11

Nerves in front of auricle: ØSupra-trochlear (S) ØSupra-orbital (S) ØZygomatico-temporal (S) ØTemporal branch of facial nerve (M) ØAuriculo-temporal nerve (S) 3/1/2021 12

Nerves behind the auricle: ØPosterior branch of great auricular nerve(S) ØPosterior auricular branch of facial nerve (M) ØLesser occipital nerve (S) ØGreater occipital nerve (S) ØThird occipital nerve (S) 3/1/2021 13

Arterial supply: Five sets of arteries supply the scalp on each side Three in front of the auricle Two behind the auricle 3/1/2021 14

Arteries in front of the auricle: Ø Supra-trochlear Ø Supra-orbital Ophthalmic artery ØSuperficial temporal External carotid artery 3/1/2021 15

Arteries behind the auricle: Ø Posterior auricular Ø Occipital artery External carotid artery 3/1/2021 16

Venous Drainage: Ø Supra-trochlear Ø Supra-orbital Ø Superficial temporal Ø Posterior auricular Ø Occipital vein 3/1/2021 17

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Emissary veins: On each side two sets of emissary veins Parietal Superior sagittal sinus Mastoid– Sigmoid sinus 3/1/2021 Emissary vein Sigmoid sinus 19

Diploic veins: Frontal diploic vein. Supra-orbital vein Occipital diploic vein– Occipital vein 3/1/2021 20

Lymphatic drainage: Anterior part of scalp. Pre-auricular Posterior part of scalp– Post-auricular 3/1/2021 21

Applied anatomy: 1. Because of the abundance of sebaceous glands, the scalp is common site of sebaceous cysts 2. Since blood supply to scalp is rich avulsed portions need not to be cut away. They can be replaced in position and stitched: they usually take up and heal away 3. Wounds of the scalp bleed profusely because of the vessels are prevented from retracting by the fibrous fascia. Bleeding can be arrested by applying pressure against the bone.

4. Because of the density of fascia, subcutaneous hemorrhages are extensive, and the inflammation in this layer cause little swelling but much pain 5. The layer of loose aerolar tissue is known as the dangerous area of scalp because emissary veins , which open here, may transmit infection from the scalp to the cranial venous sinuses 6. Collection of blood in the layer of loose connective tissue causes generalized swelling of the scalp. The blood may extend anteriorly into the root of the nose and into the eyelids, causing black eye