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 carotid artery is the large vertical artery in red. The blood supply to the common carotid artery starts at the arch of the aorta (left) or the subclavian artery (right). The common carotid artery divides into the internal carotid artery and the external carotid artery.