25/09/2026
The human neck is far more complex than it appears from the outside. Beneath the skin are several carefully arranged layers that protect and support important structures. The outermost skin contains sensory nerves, hair follicles, sweat glands, oil glands and small blood vessels. Underneath is the subcutaneous tissue, which contains varying amounts of fat, lymphatic vessels, nerves and blood vessels. This layer provides cushioning and allows the skin to move over deeper tissues. Within the superficial fascia is the platysma, a thin sheet-like muscle extending from the upper chest toward the lower face. It helps move the skin of the neck and lower face.
Deeper inside is the deep cervical fascia, a strong network of connective tissue that surrounds, separates and supports structures throughout the neck. It includes the investing fascia around muscles such as the sternocleidomastoid and trapezius, the pretracheal fascia surrounding structures in the front of the neck, and the prevertebral fascia surrounding the cervical spine and deep muscles. The carotid sheath is another important fascial structure. It surrounds the carotid artery, internal jugular vein and vagus nerve. These fascial layers also create spaces between tissues, which provide pathways for nerves and vessels and can sometimes allow infections or fluid to spread.
Within and beneath these layers are numerous muscles, blood vessels and nerves. The neck muscles include the sternocleidomastoid, trapezius, scalene muscles, levator scapulae, prevertebral muscles, and the suprahyoid and infrahyoid muscle groups. These muscles help control head movement, posture, swallowing and speech. Major blood vessels include the carotid arteries, which carry blood toward the brain, and the internal jugular veins, which return blood toward the heart. Important nerves include the vagus nerve, phrenic nerve, cervical plexus and sympathetic trunk. The neck also contains lymph nodes and lymphatic vessels that are part of the body's immune system.
At deeper levels are the thyroid and parathyroid glands, larynx, trachea and esophagus. The thyroid helps regulate metabolism through hormone production, while the parathyroid glands help control calcium levels. The larynx is involved in breathing and producing sound, while the trachea carries air toward the lungs and the esophagus transports swallowed food toward the stomach. At the deepest region are the prevertebral muscles, cervical vertebrae and spinal cord. The spinal cord passes through the protected vertebral canal and is surrounded by the meninges and cerebrospinal fluid. Together, these layers form a highly organized three-dimensional system that allows the neck to move while protecting vital organs, nerves, blood vessels and the connection between the brain and the rest of the body.