In Depth: Bones & Vessels
As the spinal column descends from the base of the skull, it forms the bony structure of the neck, the part of the body between the skull and the shoulder.
The spinal column is about two dozen interconnected, oddly shaped bony segments called vertebrae. It extends from the base of the skull to the pelvis and gives human beings the ability to stand upright. The spinal column also connects to the ribs, 12 pairs of curved bones that protect vital organs such as the lungs and heart. The neck contains the cervical vertebrae, the seven smallest.
The spinal column protects and houses the spinal cord, the long bundle of nervous tissue that transmits neural signals to the brain and rest of body. It connects to the brain and travels down to the small of the back. Its branches cover nearly every surface of the body.
The neck is also a passageway for the blood supply in the head. The external and internal carotid arteries travel on both sides of the neck. The internal and external jugular veins, the main thoroughfares for blood returning to the heart, run along the sides of the neck as well. The carotid arteries are used to check the pulse in the neck.
The internal carotid artery travels up from the aortic arch just outside the heart. It travels into the head to provide oxygenated blood to the eyes, the front of the brain, and portions of the scalp.
The external carotid artery helps supply part of the brain, and it also gives blood to the thyroid gland in the front of the neck.
Because the neck’s only protection comes from the vertebral column, it is prone to injury during high-impact accidents, including car accidents, falls from heights, or head-on impacts. Whiplash is a common injury during these types of accidents, when the head suddenly jerks away from the body.
Damage to the carotid arteries or jugular veins poses severe, immediate health risks due to blood loss and can be fatal without immediate medical treatment.