The scalp is supplied by the frontal, supra-orbital, and sometimes a small branch from the lachrymal arteries, from the ophthalmic; by the temporal, through its anterior and posterior branches; and by the posterior auricular and the occipital arteries from the external carotid. These arteries communicate freely with each other, not only laterally, but also across the top of the scalp. It is not unusual to see a large branch of the temporal communicating directly with the occipital.

Fig. 5.   Arteries of the scalp.

Fig. 5. - Arteries of the scalp.

The temporal artery begins in the substance of the parotid gland, just below the condyle of the jaw, and mounts over the zygoma, a centimetre (or less) in front of the ear. It lies on the temporal fascia and its pulsations can be felt at this point, if desired, during the administration of an anaesthetic. About four centimetres (1 1/2 in.) above the zygoma, it divides into the anterior and posterior branches. The auriculotemporal branch of the fifth nerve lies just in front of the ear and between it and the temporal artery.

The occipital artery mounts to the scalp in the interval between the posterior border of the sternomastoid muscle and the anterior border of the trapezius. It is about midway between the posterior border of the mastoid process and the occipital protuberance. If it is desired to expose it from this point forward, the sternomastoid, splenius capitis, and trachelomastoid muscles will have to be cut, because it passes beneath them. The occipitalis major nerve lies to the inner side of the artery.

Fig. 6.   Occipital artery.

Fig. 6. - Occipital artery.

Lymphatics Of The Scalp

The lymphatics anteriorly near the median line pass down between the orbits to reach the submaxillary nodes. Those of the anterior parietal and temporal regions empty into the pre-auricular nodes; those of the posterior parietal and temporal, into the nodes behind and below the ear; and those of the occipital region into the occipital nodes. Infectious troubles of these regions, therefore, will cause enlargement of the corresponding nodes.