palmar

Palmar is an anatomical term describing structures on or relating to the palm of the hand, the anterior or palmar surface. The word derives from Latin palma, meaning palm.

Anatomy and structure

The palmar aspect of the hand includes skin, subcutaneous tissue, and a thick connective tissue layer called the palmar fascia or palmar aponeurosis. This fascia is a triangular sheet that anchors to the skin and to the distal palm, playing a role in hand function and in shaping the thenar and hypothenar regions. The internal structures of the palm include the flexor tendons, intrinsic hand muscles, and the arterial and nerve supplies that service the digits.

Palmar fascia and regions

The palmar aponeurosis protects deeper structures and contributes to grip by maintaining the integrity of the superficial palm. It extends from the distal wrist crease toward the fingers and provides attachments that help stabilize the skin and hand during grasping. Disorders of the palmar fascia, such as Dupuytren’s contracture, can lead to progressive finger flexion contractures.

Vascular supply

The palm receives blood from the superficial and deep palmar arches. The superficial arch is mainly formed by the ulnar artery with contributions from the radial artery, while the deep arch is primarily from the radial artery with contributions from the ulnar artery. These arches give rise to digital arteries that supply the fingers.

Nerve innervation

Sensory and motor innervation of the palm come from the median nerve (lateral three and a half digits) and the ulnar nerve (medial one and a half digits), with the radial nerve contributing sensation to a portion of the lateral palm and the dorsum.

Clinical notes

Palmar anatomy is evaluated in physical examinations for nerve injuries, tendon injuries, or conditions such as hyperhidrosis (excessive sweating of the palms) and Dupuytren’s contracture. The palmar surface is also a focus in procedures involving reconstructive and traumatic hand care.