Scalp Anatomy Overview

Scalp Definition and Extent

• The scalp is the soft tissue covering the vault of the skull.
• It extends from the eyebrows anteriorly, superior nuchal line and external occipital protuberance posteriorly, and superior temporal lines laterally.

Layers of the Scalp

• The scalp consists of five layers: skin, connective tissue, epicranial aponeurosis, loose connective tissue, and pericranium.
• The scalp contains sebaceous glands, blood vessels, and nerves, and attaches to the occipitofrontalis muscle.

Occipito-Frontalis Muscle

• The occipito-frontalis muscle consists of two frontal bellies and two occipital bellies connected by the epicranial aponeurosis.
• The frontal bellies attach to the skin of the forehead and eyebrows, while the occipital bellies attach to the epicranial aponeurosis and superior nuchal line.
• The muscle is supplied by the facial nerve (temporal branch for frontal bellies and posterior auricular branch for occipital bellies).
• The muscle moves the scalp forward and backward, elevates the eyebrows, and causes transverse wrinkles on the forehead.

Arterial Supply of the Scalp

• The scalp is supplied by five arteries on each side: three in front of the auricle and two behind it.
• The supratrochlear, supraorbital, and superficial temporal arteries supply the scalp in front of the auricle.
• The posterior auricular and occipital arteries supply the scalp behind the auricle.

Venous Drainage of the Scalp and Face

• The supraorbital and supratrochlear veins unite to form the anterior facial vein.
• The superficial temporal vein unites with the maxillary vein to form the retromandibular vein.
• The retromandibular vein divides into anterior and posterior divisions, which unite with the anterior facial vein and posterior division of the retromandibular vein, respectively.
• The posterior auricular vein unites with the posterior division of the retromandibular vein to form the external jugular vein.
• The occipital vein drains into the suboccipital venous plexus.

Nerve Supply of the Scalp

• In front of the auricle, four sensory branches from the trigeminal nerve supply the scalp.
• The supratrochlear and supraorbital nerves supply the anterior part of the scalp.
• Behind the auricle, four sensory branches from the cervical nerves supply the scalp.
• The great auricular nerve supplies the skin of the lower part of the auricle and skin opposite the angle of the mandible.

Learn about the definition, extent, layers, and key features of the scalp, including the soft tissues covering the skull vault. Explore details about the layers of the scalp, blood vessels, nerves, and muscles attached to it.