Neck Anatomy Overview

The superior border of the neck is formed by the inferior margin of the mandible anteriorly and the base of the skull posteriorly.

The inferior border of the neck is defined by the top of the sternum, clavicle, adjacent acromion, and a line from the acromion to the spinous process of the 7th cervical vertebra.

The neck houses vital functions like head support, passage of blood vessels and nerves, and connecting the oral and nasal cavities to the digestive and respiratory systems.

The vertebral compartment of the neck encloses the cervical vertebrae, spinal cord, cranial nerves, and associated postural muscles.

The visceral compartment of the neck surrounds glands like the thyroid and parathyroid, and portions of the respiratory and digestive systems passing between the head and thorax.

The vascular compartments of the neck, located on each side, contain major blood vessels and the vagus nerve (CN X).

The deep cervical fascia, a layer of connective tissue, wraps around to define compartments within the neck, separating and supporting various structures.

Arises anteriorly from the external carotid artery, courses deep to the hyoglossus muscle, and supplies the muscles of the tongue, sublingual gland, and floor of the mouth.

The first branch of the external carotid artery, supplies the thyroid gland, larynx, and surrounding neck muscles.

Arises posteriorly from the external carotid artery, runs superiorly and posteriorly, and supplies structures of the posterior scalp and deep back muscles.

A small branch of the external carotid artery, supplies the parotid gland, external ear, and parts of the scalp posterior to the ear.

A thick layer of fascia surrounding the major blood vessels and nerves of the neck.

Nerve that supplies the skin of the parotid region, ear, and mastoid area. It ascends across the sternocleidomastoid muscle from its posterior border to the base of the ear.

Nerve arises from C2 and C3 spinal nerves. It travels horizontally across the sternocleidomastoid muscle, supplying the lateral and anterior parts of the neck.

Group of cutaneous nerves emerging from beneath the posterior border of the sternocleidomastoid muscle. They descend and supply the skin over the clavicle and shoulder down to rib II.

Nerve that exits the skull through the jugular foramen. It innervates the sternocleidomastoid and trapezius muscles.

Region of the neck bounded by the anterior edge of the sternocleidomastoid muscle, the inferior edge of the mandible, and the midline of the neck.

Triangle within the anterior triangle, bounded by the inferior border of the mandible, the digastric muscle, and the investing layer of deep cervical fascia.

Large salivary gland located in the submandibular triangle, 'hooked' around the posterior margin of the mylohyoid muscle.

Triangle within the anterior triangle, bounded by the hyoid bone, the anterior belly of the digastric muscle, and the midline of the neck.

Triangle within the anterior triangle, bounded by the hyoid bone, the superior belly of the omohyoid muscle and the anterior border of the sternocleidomastoid muscle.

Muscle that helps to depress the hyoid bone. It has two bellies: an inferior belly that passes through the posterior triangle and a superior belly that divides the muscular and vascular triangles of the anterior triangle.

A space located between the buccopharyngeal and prevertebral fascia, extending from the base of the skull to the upper part of the posterior mediastinum.

A longitudinal space filled with loose connective tissue (LCT) between the two layers of prevertebral fascia, extending from the base of the skull through the posterior mediastinum to the diaphragm.

These spaces act as pathways for the spread of infections from the neck to the mediastinum.

A large, thin sheet of muscle located in the superficial fascia of the neck, extending from the superficial fascia of the upper thorax to the mandible and muscles around the mouth.

A large vein formed posteriorly to the angle of the mandible by the posterior auricular vein and retromandibular vein. It runs downward superficial to the sternocleidomastoid muscle and pierces the investing layer to join the subclavian vein at the inferior aspect of the sternocleidomastoid.

A variable and inconsistent vein that begins as small veins which come together around the hyoid bone and extend inferiorly, connecting at the jugular venous arch. It joins the subclavian vein directly or joins the external jugular vein.

Situated in the neck, with the following boundaries: - Posterior border of the sternocleidomastoid (anterior) - Anterior border of the trapezius (posterior) - Middle 1/3 of the clavicle (inferior) - Investing layer of deep cervical fascia (roof) - Muscles of the neck in the prevertebral fascia (floor)

A muscle that originates from the sternum and clavicle and inserts into the mastoid process and superior nuchal line of the skull. It tilts and rotates the head, and pulls it forward when both contract.

A muscle that originates from the superior nuchal line, external occipital protuberance, ligamentum nuchae, and spinous processes of C7-T12 vertebrae. It inserts into the lateral ½ of the clavicle, acromion, and spine of the scapula, rotating, elevating, retracting, and depressing the scapula.

A muscle that originates from the posterior surface of the sternal manubrium, inserts on the oblique line of the thyroid cartilage, and depresses the larynx.

A muscle that originates from the greater horn and adjacent body of the hyoid bone, inserts on the oblique line of the thyroid cartilage, and depresses the hyoid bone. This action is crucial in swallowing.

This muscle originates from the base of the styloid process, inserts on the lateral body of the hyoid bone, and pulls the hyoid posterosuperiorly during swallowing.

A muscle that originates from the mastoid notch and the digastric fossa of the mandible, inserts on the intermediate tendon attached to the body of the hyoid bone, and elevates the hyoid bone during swallowing.

The deep belly of the digastric muscle originates from the mastoid notch, and the superficial belly originates from the digastric fossa on the inferior mandible. Both bellies insert on the intermediate tendon attached to the body of the hyoid bone. This muscle elevates the hyoid bone and opens the mouth during swallowing.

This muscle originates from the inferior mental spine on the inner surface of the mandible, inserts on the anterior surface of the body of the hyoid bone, and elevates the hyoid bone during swallowing.

A nerve that supplies the thyrohyoid muscle, originates from the ansa cervicalis, and travels with the hypoglossal nerve.

A loop of nerves formed by the ventral rami of cervical nerves C1-C3, and supplies most of the infrahyoid muscles (sternothyroid, omohyoid, sternohyoid, and thyrohyoid).

This muscle originates from the superior border of the scapula, inserts on the inferior border of the hyoid bone, and depresses the hyoid bone. This action helps in swallowing and vocalization.

This muscle originates from the medial surface of the manubrium of the sternum and the superior part of the first costal cartilage, inserts on the inferior margin of the hyoid bone, and depresses the hyoid bone. It helps in swallowing and speaking.