Common carotid artery At approximately the level of the fourth cervical vertebra, the common carotid artery splits ("bifurcates" in literature) into an internal carotid artery (ICA) and an external carotid artery (ECA). While both branches travel upward, the internal carotid takes a deeper (more internal) path, eventually travelling up into the skull to supply the brain. The external carotid artery travels more closely to the surface, and sends off numerous branches that supply the neck and face. At the lower part of the neck the common carotid artery is very deeply seated, being covered by the integument, superficial fascia, the platysma muscle, deep
Composition of the human body g in men, ~2.3 g in women Of the 94 naturally occurring chemical elements, 60 are listed in the table above. Of the remaining 34, it is not known how many occur in the human body. Most of the elements needed for life are relatively common in the Earth's crust. Aluminium, the third most common element in the Earth's crust (after oxygen and silicon), serves no function in living cells, but is harmful in large amounts. Transferrins can bind aluminium. The composition of the human body is expressed in terms of chemicals: The composition of the human body can be