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Ehab ZAYYAN, MD, PhD. Otolaryngology & Head and Neck Surgery Hacettepe University School of Medicine Ankara- Turkey ENT Consultant European Gaza Hospital Assistant Professor Islamic University- Faculty of Medicine. The Scalp. SCALP. S kin C onnective tissue A poneurosis
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Ehab ZAYYAN, MD, PhD Otolaryngology & Head and Neck Surgery Hacettepe University School of Medicine Ankara- Turkey ENT Consultant European Gaza Hospital Assistant Professor Islamic University- Faculty of Medicine
SCALP Skin Connective tissue Aponeurosis Loose areolar tissue Periosteum (Pericranium)
1. Skin Thick and hair bearing and contains numerous sebaceous glands
2. Superficial fascia • Dense fibro- fatty connective tissue. • Firmly attached to the skin and the aponeurosis. • Numerous arteries, veins and nerves. • Free anastomosis between the ICA an ECA branches.
3. Epicranial Aponeurosis • Epicranius = occipitofrontalis muscle + galea aponeurotica • A thin tendinous sheet that unites the occipital and frontal bellies of the occipitofrontalis muscle. • The lateral margins of the aponeurosis are attached to the temporal muscle fascia. • The subaponeurotic space: potantial space beneath the aponeurosis. Limited by the muscle origin and attachment and laterally by the temporal muscle fascia.
4. Loose areolar tissue • Occupies the subaponeurotic space • Few small arteries • Emissary veins: valveless and connect the superficial veins of the scalp with the diploic veins of the skull bones and with intracranial venous sinuses. • Called the danger area of the scalp: extravasated blood spreads easily within it
5. Pericranium • The periosteum of the outer surface of the skull bones. • At the sutures of the bones it is continuous with the inner periosteum.
Occipoitofrontalis muscle • Two occipital and two frontal bellies, connected by aponeurosis • The occipital bellies originate from the superior nuchal line on the occipital bone and insert into the aponeurosis. • The frontal bellies arise from the superficial fascia of the eyebrows and inserts into the aponeurosis
Nerve supply Facial nerve → temporal branch → frontal belly Facial nerve → posterior auricular branch → occipital belly
Action • The first layers of the scalp can move forward or backward as one unit • The frontal bellies raise the eyebrows
Scalp sensory nerve supply • Lie in the superficial fascia • Supratrochlear nerve (from V1) • Supraorbital nerve (from V1) • Zygomaticotemporal nerve (from V2) • Auriculotemporal nerve (from V3) • Lesser occipital nerve (C2) • Greater occipital nerve (post ramus of C2)
Arterial supply of the scalp • Very rich blood supply • Supratrochlear and supraorbital arteries (from ophthalmic arteries, from ICA) • Superficial temporal artery (terminal branch of the ECA) • Posterior auricular artery (ECA) • Occipital artery (ECA)
Venous drainage of the scalp • The veins of the scalp freely anastomose with one another and are connected to the diploic veins of the skull bones and the intracranial venous sinuses by the valvless emissary veins.
Supratrochlear + supraorbital veins → facial vein • Superficial temporal + maxillary veins → retromandibular vein • Posterior auricular vein + post division of the retromandibular vein → external jugular vein • The occipital vein → suboccipital venous plexus → vertebral veins or IJV
Lymphatic drainage • Submandibular lymph nodes • Superficial parotid lymph nodes (preauricular) • Mastoid lymph nodes (postauricular) • Occipital nodes
Clinical • Sabaceous cysts are common in the scalp. (trauma by combs) • Lacerations of the scalp: arterial walls attaches to fibrous septa → unable to contract and stop bleeding. Pressure is a good method. • Large defects can be sutured • The aponeurosis tension: should be sutured in all deep wounds
Clinical • Life threatening scalp hemorrhage: encircle the head by a tourniquet just above the ears and eyebrows • Scalp infections: Usually localized. But may spread via the emissary vein → osteomyelitis and venous sinus thrombosis
Potential space beneath the aponeurosis: The frontalis muscle has no bony attachment in the forehead. It is integrated with the fibers of the orbicularis oculi muscle and the skin of the forehead and eyelids → liquid material can not pass into the neck or laterally but can track into the upper eyelid and forehead.