ANATOMY

Detailed explanation-1: -The radial artery and ulnar artery parallel their namesake bones, giving off smaller branches until they reach the wrist, or carpal region. At this level, they fuse to form the superficial and deep palmar arches that supply blood to the hand, as well as the digital arteries that supply blood to the digits.

Detailed explanation-2: -The left and right brachiocephalic vein join to form the superior vena cava on the right side of the upper chest. These vessels are a vital component of the human circulatory system, aiding in drainage of deoxygenated blood from the head and upper limbs.

Detailed explanation-3: -The popliteal vein is formed by the confluence of the deep veins of the leg, i.e. the posterior tibial, anterior tibial and common fibular veins. It also receives venous blood from the superficial vein of the lateral leg, i.e. the short saphenous vein.

Detailed explanation-4: -The hepatic portal vein is formed from the superior mesenteric vein and the splenic vein (which drains the inferior mesenteric vein).