If you are planning a hard-to-get Alcatraz tour, you will need to really layer clothes for a variety of temperatures. The weather varies greatly from month to month and hour to hour. Even the neighborhood youre in makes a difference. For many visitors, the San Francisco weather can be counter-intuitive.
The carotid arteries are major blood vessels in the neck that supply blood to the brain, neck, and face. There are two carotid arteries, one on the right and one on the left. In the neck, each carotid artery branches into two divisions: 1  The internal carotid artery supplies blood to the brain.
The common carotid arteries split into two main branches â the internal carotid artery and the external carotid artery. The external carotid artery is the only division of the common carotid that gives branches to the neck region and supplies the external structures of the head and face.