Internal carotid artery of the posterior communicating artery to the bifurcation of the internal carotid artery. The named branches of the communicating segment are: The internal carotid then divides to form the anterior cerebral artery and middle cerebral artery. The internal carotid artery can receive blood flow via an important collateral pathway supplying the brain, the cerebral arterial circle, which is more commonly known as the Circle of Willis. The following are the branches of the internal carotid artery, listed by segment: The sympathetic trunk forms a plexus of nerves around the artery known as the carotid plexus. The internal carotid nerve arises
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