These arteries form three arches over the dorsal and palmar aspects of the hand, the dorsal carpal arch (across the back of the hand), the deep palmar arch, and the superficial palmar arch. Together these three arches and their anastomoses provide oxygenated blood to the palm, the fingers, and the thumb. The hand is drained by the dorsal venous network of the hand with deoxygenated blood leaving the hand via the cephalic vein and the basilic vein. Skin
The glabrous (hairless) skin on the front of the hand, the palm, is relatively thick and can be bent along the hands flexure lines where the skin is tightly bound to the underlying tissue and bones. Compared to the rest of the bodys skin, the hands palms (as well as the soles of the feet) are usually lighter—and even much lighter in dark-skinned individuals, compared to the other side of the hand. Indeed, genes specifically expressed in the dermis of palmoplantar skin inhibit melanin production and thus the ability to tan, and promote the thickening of the stratum lucidum and stratum corneum layers of the epidermis. All parts of the skin involved in grasping are covered by papillary ridges (fingerprints) acting as friction pads. In contrast, the hairy skin on the dorsal side is thin, soft, and pliable, so that the skin can recoil when the fingers are stretched.
Areas
Areas of the human hand include:

The palm (Volar), which is the central region of the anterior part of the hand, located superficially to the metacarpus. The skin in this area contains dermal papillae to increase friction, such as are also present on the fingers and used for fingerprints. The opisthenar area (dorsal) is the corresponding area on the posterior part of the hand. The heel of the hand is the area anteriorly to the bases of the metacarpal bones, located in the proximal part of the palm. It is the area that sustains most pressure when using the palm of the hand for support, such as in handstand.There are five digits attached to the hand, notably with a nail fixed to the end in place of the normal claw. The four fingers can be folded over the palm which allows the grasping of objects. Each finger, starting with the one closest to the thumb, has a colloquial name to distinguish it from the others:

index finger, pointer finger, forefinger, or 2nd digit
middle finger or long finger or 3rd digit
ring finger or 4th digit
little finger, pinky finger, small finger, baby finger, or 5th digitThe thumb (connected to the first metacarpal bone and trapezium) is located on one of the sides, parallel to the arm. A reliable way of identifying human hands is from the presence of opposable thumbs. Opposable thumbs are identified by the ability to be brought opposite to the fingers, a muscle action known as opposition.