Scalp Anatomy Overview

10 Questions

Which nerve provides motor innervation to the frontal belly of the occipitofrontalis muscle?

Facial nerve

Which nerve supplies sensory innervation to the anterior part of the scalp close to the median plane?

Supraorbital nerve

What is the origin of the supratrochlear nerve?

Ophthalmic division of the trigeminal nerve

Which nerve supplies sensory innervation to the posterior half of the lateral surface of the scalp?

Greater auricular nerve

Which nerve provides motor innervation to the occipital belly of the occipitofrontalis muscle?

Cervical nerves

Which nerve supplies sensory innervation to the skin of the lower part of the auricle and the skin opposite the angle of the mandible?

Great auricular nerve

Which nerve provides sensory innervation to the anterior half of the lateral surface of the scalp?

Zygomaticotemporal nerve

Which nerve originates from the mandibular division of the trigeminal nerve?

Auriculotemporal nerve

Which nerve provides sensory innervation to the area around the auricle?

Great auricular nerve

Which nerve is responsible for supplying motor innervation to the muscles of facial expression?

Facial nerve

Study Notes

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.