Cervical Blood Vessels
There are a number of major blood vessels in the cervical spinal region including: the brachiocephalic vein; the internal jugular vein; the subclavian vein; the external jugular vein; and the right common carotid artery. As the cervical spine is a complex region with many tightly packed structures, it is not uncommon for these blood vessels to occasionally be impinged upon. Problems with circulation through the neck to the brain are connected to disease conditions such as multiple sclerosis, as well as stroke and vascular dementia.
Blood travelling up to the head originates from the aortic arch’s upper systemic loop and travels through the brachiocephalic artery, the left common carotid artery, and the left subclavian artery. The brachiocephalic artery branches into the right common carotid artery and the right subclavian artery and provides blood not just for the head but for the right upper chest, right arm, and neck, through the right vertebral artery. The left subclavian artery provides the left upper chest and left arm with blood. Together the left and right subclavian arteries form the internal thoracic artery which supplies the anterior chest wall and the breasts.
The thyrocervical trunk is also a branch of the subclavian artery which originates between the subclavian artery’s root and the inner edge of the anterior scalenus muscle. This cervical blood vessel is thick and short and soon branches into the inferior thyroid artery, the suprascapular artery, and the transverse cervical artery. The costocervical trunk also arises from the subclavian artery towards the upper back region of the vessel. This trunk is behind the anterior scalenus muscle too, on the right hand side, and splits to form the deep cervical artery and the supreme intercostal artery. The supreme intercostal artery is the uppermost intercostal artery which lies behind the pleura covering the front of the first and second ribs. The costocervical trunk can also branch off as it enters the first intercostal space, although sometimes this branch is not present and the area is supplied with blood from an intercostal branch of the aorta. When conducting surgery on the chest surgeons will usually establish the location of this branch in the right side, taking care not to assume its presence or absence.
The right and left vertebral arteries feed into the basilar artery and then the posterior cerebral artery which supplies the brain with most of its oxygenated blood. The internal carotid artery also provides the brain with blood, while the external carotid artery supplies blood to the neck and face. These two arteries are divisions of the left common carotid artery. Blood leaving the head to return to the heart is drained by the subclavian vein and jugular vein. The right and left jugular veins drain the blood from the parotid glands, facial muscles, and scalp, leading into the subclavian veins. The right and left vertebral veins drain the vertebrae and muscles in the neck into the right subclavian vein and the superior vena cava which lead into the right atrium of the heart.
Problems of Blood Supply in the Neck
Certain conditions of the cervical spine can compromise the function of these major cervical blood vessels, preventing proper circulation and causing ischaemia and neck pain. In extreme circumstances and injury to the neck can cut or sever one of these blood vessels which may affect circulation to the brain and cause a loss of consciousness. The presence of cervical ribs can lead to compression of the blood vessels in the neck, such as the subclavian artery, or to nerves in the brachial plexus. Muscle pain, numbness, tingling, and weakness are all symptoms that may be attributed to blood vessel compression, as well as nerve compression in the cervical spine. If the hands feel peculiarly cold, particularly if there is a marked difference in temperature in one hand over the other then there may be a problem with compression of the brachial plexus and the potential for thoracic outlet syndrome. Patients are advised to check their symptoms with their doctor.
Sometimes an acute injury, such as whiplash can cause problems with the blood vessels. In this case it is usually due to inflammation in the neck muscles which then decreases blood circulating through smaller blood vessels. As blood supply to the muscles decreases the muscle tissue can deteriorate, which may lead to further inflammatory responses and more compression on the blood vessels. If this happens then simple activities such as dressing oneself can become difficult.
There is also some cause for concern regarding the cervical blood vessels in the neck as the cervical spine is unique in that it has blood vessels directly exiting through the vertebrae. Each cervical vertebra has special openings through which the arteries supplying blood to the brain can pass. These holes are called foramen and occur in the transverse process of the cervical vertebrae where the lamina joins the pedicle. Osteophyte growth, fracture, or degeneration in the cervical vertebrae can put pressure on these blood vessels and the nerves which also pass through gaps in the spinal column.