The left common carotid artery branches directly from the arch of aorta. This bifurcation occurs roughly at the level of the right sternoclavicular joint. The right common carotid artery arises from a bifurcation of the brachiocephalic trunk (the right subclavian artery is the other branch). We shall start at the origin of the carotid arteries. This article shall explore the anatomy of this arterial system - its anatomical course, branches, and clinical correlations. The head and neck receives the majority of its blood supply through the carotid and vertebral arteries. The maxillary artery supplies the deep structures of the face, while the facial and superficial temporal arteries generally supply superficial areas of the face. The facial, maxillary and superficial temporal arteries are the major branches of note. The artery ends within the parotid gland by dividing into the superficial temporal artery and the maxillary artery. After arising from the common carotid artery, it travels up the neck, passing posteriorly to the mandibular neck and anteriorly to the lobule of the ear. The external carotid artery supplies the areas of the head and neck external to the cranium. These cells act as peripheral chemoreceptors detecting the O2 content of the blood and relaying this information to the brain to regulate breathing rate. In such patients, checking the pulse at the carotid triangle is not advised.Įxternal to the carotid sinus, there is a cluster of nervous cells known as the carotid body. The brain becomes under-perfused and syncope results.

External pressure on the carotid sinus can cause slowing of the heart rate and a decrease in blood pressure. In some individuals, the baroreceptors are hypersensitive to stretch. The glossopharyngeal nerve feeds this information to the brain, and this is used to regulate blood pressure. These cells detect stretch as a measure of blood pressure. It contains specialised sensory cells known as baroreceptors. The carotid sinus is a dilated portion of the common carotid artery and proximal internal carotid artery. Clinical Relevance: Carotid Sinus Hypersensitivity

Back of neck diagram