The carotid sheath is an anatomical term for the fibrous connective tissue that surrounds the vascular compartment of the neck. It is part of the deep cervical fascia of the neck, below the superficial cervical fascia meaning the subcutaneous adipose tissue immediately beneath the skin.
Section of the neck at about the level of the sixth cervical vertebra. Showing the arrangement of the fascia coli. Carotid sheath is labeled in red.
|Latin||vagina carotica fasciae cervicalis|
The deep cervical fascia of the neck includes four parts:
- The investing layer (encloses the SCM and Trapezius)
- The carotid sheath (encloses the vascular region of the neck)
- The pretracheal fascia (encloses the visceral region of the neck)
- The prevertebral fascia (encloses the vertebral region of the neck)
The carotid sheath is located at the lateral boundary of the retropharyngeal space at the level of the oropharynx on each side of the neck and deep to the sternocleidomastoid muscle, extending from the base of the skull to the first rib and sternum.
The four major structures contained in the carotid sheath are:
- the common carotid artery as well as the internal carotid artery (medial)
- internal jugular vein (lateral)
- the vagus nerve (CN X) (posterior)
- the deep cervical lymph nodes
The carotid artery lies medial to the internal jugular vein, and the vagus nerve is situated posteriorly between the two vessels.
The ansa cervicalis is embedded in the anterior wall of sheath. It is formed by "descendens hypoglossi" (C1) and "descendens cervicalis" (C2-C3).