Circulation to the upper limb and hand:

Blood is pumped around the body by the heart. The blood vessels taking blood away from the heart to the tissues and organs are called "arteries". Arteries are very strong as the blood is pumped at high pressure. The arterial wall is made of special muscle called "smooth muscle"..

The heart pumps blood out into the major artery in the body called the Aorta. The first part of this is called the ascending aorta - the next part is called the Arch of the Aorta. There are 3 branches from the arch of the aorta - the Innominate (or Brachiocephalic) artery, the left Common Carotid Artery and the left Subclavian Artery. The Innominate or Brachiocephalic Artery divides into the right Subclavian and right Common Carotid Arteries.

From the Subclavian Arteries onwards, the blood supply to left and right arms and hands are identical.

The Subcalvian Artery follows thorough to the arm-pit (Axilla) where it is called the Axillary artery, and goes on into the upper arm where it is called the Brachial Artery. Just below the elbow, the Brachial Artery divides into 2 - the Ulnar and Radial Arteries. The Ulnar Artery runs down the side of the forearm that is on the little finger side - the Radial Artery runs down the forearm on the Thumb side.

In the hand, both arteries meet and connect in the Palmar Arch. Actually there are 2 Palmar arches - the Deep and Superfical Palmar Arches. Each of the digits - thumb and each finger - has 2 Digital Arteries. These arise from the Palmar Arches and run up each side of the bone in each digit.