21 The internal carotid artery and its branches
The internal carotid artery is very difficult to feel at its origin and impossible to palpate along its intracranial course. Happily, some of its terminal branches appear on the face where they are fairly easily palpated. These branches serve mainly to direct us to the side of reduced cerebral blood flow, and enable us to evaluate our results.
The internal carotid (Fig. 21.1) begins at the bifurcation of the common carotid, between the hyoid bone and the superior border of the thyroid cartilage, at the level of C3 or C4. It is located lateral and posterior to the external carotid artery as it ascends the neck.
In the neck, the internal carotid artery has the same positioning as the external carotid, although it is slightly lateral and posterior to it. The internal carotid is initially superficial, covered only by skin, the platysma, and the superficial cervical aponeurosis.
At the base of the skull the glossopharyngeal, vagus, and hypoglossal nerves are positioned posterior to the internal carotid artery. They then circumvent it and are lateral to the internal carotid artery.