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 right common carotid artery arises from the brachiocephalic trunk (posterior to the right sternoclavicular joint), whereas the left common carotid is a branch of the arch of the aorta and hence has a thoracic portion before it reaches the neck (posterior to the left sternoclavicular joint).