Neck

The neck is the part of the body that connects the head to the trunk. It contains a complex arrangement of bones, muscles, vessels, nerves, and other structures that support head movement, protect vital pathways, and allow the passage of air and food. The neck also houses several glands and a network of lymph nodes that participate in immune function.

Anatomy is organized around the cervical spine, formed by seven vertebrae (C1–C7). The atlas (C1) and axis (C2) enable most head rotation, while the other vertebrae contribute to flexion, extension, and lateral movement. Intervertebral discs cushion the joints, and ligaments plus muscles stabilize the region. The major muscles include the sternocleidomastoid, which rotates and tilts the head, the scalene group, and the deeper strap and back muscles that support posture. The neck also contains the trachea, esophagus, the thyroid and parathyroid glands, the common carotid arteries and internal jugular veins, and the vagus and accessory nerves, along with a network of cervical lymph nodes.

Functionally, the neck supports the head’s weight, enables wide ranges of motion, and provides access to the thorax and abdomen for airflow, swallowing, and vascular supply. It also serves as a conduit for nerves and vessels that supply the head, face, and upper limbs. Variation in length, musculature, and fat distribution reflects individual anatomy and age-related changes.

Common conditions affecting the neck include muscle strain and whiplash injuries, cervical spondylosis, torticollis, lymphadenopathy, and thyroid or other gland disorders. Injuries and degenerative changes can impact mobility and supply to the head and upper body.