Carotid artery - anatomy
The common carotid artery (CCA) runs from the base of the neck towards the skull. There is one on each side. At about the angle of the jaw it divides into 2 branches - the external carotid artery (ECA) which supplies blood to the face, nose and throat and the internal carotid artery (ICA) which supplies blood to the eye and part of the brain. This part of the brain controls body movement and receives sensation from the body.
Base of neck this side
Head
this side
There are various nerves which are near the arteries and therefore liable to injury during the operation. Nerves supplying the skin of the neck invariably get cut. The vagus nerve supplies the heart and most of the abdominal organs. It also gives a branch which supplies the vocal cords. The hypoglossal nerve (XII) controls the muscle in the tongue. If it is cut the tongue muscle on that side will become weaker - such that when the patient tries to stick the tongue out, it move towards the weaker side.