The human hand is a complex structure that allows for intricate movements and a wide range of sensory experiences. Many common body parts have specific scientific names that are not widely known outside of medical settings. Understanding the precise terminology for the hand’s surfaces provides clarity about its function and the structures that lie beneath the skin. This specialized vocabulary helps accurately describe the location of nerves, vessels, and bones.
The Anatomical Terminology
The specific anatomical term for the back of the hand is the Dorsum Manus, or the dorsal surface of the hand. This name is derived from the Latin word dorsum, which translates directly to “back” or “upper surface.” In anatomical positioning, “dorsal” describes the side of a structure directed away from the ground or the front of the body.
This term distinguishes the back of the hand from its opposite side, known as the palmar or ventral surface. The use of “dorsal” and “palmar” provides a precise and unambiguous directional reference. This standardized terminology ensures that medical professionals can communicate about specific locations without confusion.
Key Structures of the Dorsal Hand
The appearance of the Dorsum Manus is defined by the structures situated immediately beneath its thin skin.
Extensor Tendons
The extensor tendons originate from muscles in the forearm and are easily visible as they cross the back of the hand toward the fingers. These tendons are responsible for straightening the fingers and the wrist, allowing for the release of objects held in the palm.
Dorsal Venous Network
A prominent feature is the superficial network of veins, known as the dorsal venous network, which is often visible just below the skin. These veins are easily seen because the back of the hand lacks the thick layer of fat and protective tissue found on the palm. Their accessibility makes the dorsal hand a common site for drawing blood or administering intravenous fluids in a clinical setting.
Skin Characteristics
The skin itself is thin, pliable, and typically covered in fine hair, unlike the thick, hairless, and ridged skin on the palmar surface. This thinness allows for maximum flexibility and movement of the underlying structures.
Function and Sensitivity
The primary role of the dorsal hand is providing a flexible covering for the mechanics of extension and facilitating a wide range of motion. The loose nature of the skin and underlying connective tissue allows the hand to be fully extended and flexed without tension. This flexibility accommodates the movements of the extensor tendons as they pull the fingers open.
The thin skin of the dorsum is innervated by sensory nerves, primarily the superficial branch of the radial nerve and the dorsal branch of the ulnar nerve. This area is sensitive to light touch, temperature, and pain, though it lacks the specialized sensory receptors found in the fingertips. The lack of thick padding makes the dorsal surface more susceptible to bruising and visible injury compared to the heavily cushioned palm.