The carpal bones are the eight small bones that make up the wrist (carpus) that connects the hand to the forearm. The term "carpus" and "carpal" is derived from the Latin carpus and the Greek καρπός (karpós), meaning "wrist". In human anatomy, the main role of the carpal bones is to articulate with the radial and ulnar heads to form a highly mobile condyloid joint, to provide attachments for thenar and hypothenar muscles, and to form part of the rigid carpal tunnel which allows the median nerve and tendons of the anterior forearm muscles to be transmitted to the hand and fingers.
The radial nerve is a nerve in the human body that supplies the posterior portion of the upper limb. It innervates the medial and lateral heads of the triceps brachii muscle of the arm, as well as all 12 muscles in the posterior osteofascial compartment of the forearm and the associated joints and overlying skin.
The median nerve is a nerve in humans and other animals in the upper limb. It is one of the five main nerves originating from the brachial plexus.
In human anatomy, the wrist is variously defined as (1) the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; (2) the wrist joint or radiocarpal joint, the joint between the radius and the carpus and; (3) the anatomical region surrounding the carpus including the distal parts of the bones of the forearm and the proximal parts of the metacarpus or five metacarpal bones and the series of joints between these bones, thus referred to as wrist joints. This region also includes the carpal tunnel, the anatomical snuff box, bracelet lines, the flexor retinaculum, and the extensor retinaculum.
The triquetral bone is located in the wrist on the medial side of the proximal row of the carpus between the lunate and pisiform bones. It is on the ulnar side of the hand, but does not directly articulate with the ulna. Instead, it is connected to and articulates with the ulna through the Triangular fibrocartilage disc and ligament, which forms part of the ulnocarpal joint capsule. It connects with the pisiform, hamate, and lunate bones. It is the 2nd most commonly fractured carpal bone.
The upper limbs or upper extremities are the forelimbs of an upright-postured tetrapod vertebrate, extending from the scapulae and clavicles down to and including the digits, including all the musculatures and ligaments involved with the shoulder, elbow, wrist and knuckle joints. In humans, each upper limb is divided into the arm, forearm and hand, and is primarily used for climbing, lifting and manipulating objects.
In human anatomy, the radial artery is the main artery of the lateral aspect of the forearm.
The ulnar artery is the main blood vessel, with oxygenated blood, of the medial aspects of the forearm. It arises from the brachial artery and terminates in the superficial palmar arch, which joins with the superficial branch of the radial artery. It is palpable on the anterior and medial aspect of the wrist.
The ulnar veins are venae comitantes of the ulnar artery. They drain the superficial venous palmar arch. They arise in the hand and terminate by uniting with the radial veins to form the brachial veins. They mostly drain the medial aspect of the forearm. They receive the venae comitantes of the anterior and posterior interosseous arteries near the elbow, as well as a large branch from the median cubital vein. The ulnar veins are larger than the radial veins.
In human anatomy, the palmar or volar interossei are four muscles, one on the thumb that is occasionally missing, and three small, unipennate, central muscles in the hand that lie between the metacarpal bones and are attached to the index, ring, and little fingers. They are smaller than the dorsal interossei of the hand.
The posterior interosseous artery is an artery of the forearm. It is a branch of the common interosseous artery, which is a branch of the ulnar artery.
The anterior interosseous artery is an artery in the forearm. It is a branch of the common interosseous artery.
The superficial palmar arch is formed predominantly by the ulnar artery, with a contribution from the superficial palmar branch of the radial artery. However, in some individuals the contribution from the radial artery might be absent, and instead anastomoses with either the princeps pollicis artery, the radialis indicis artery, or the median artery, the former two of which are branches from the radial artery.
The deep palmar arch is an arterial network found in the palm. It is usually primarily formed from the terminal part of the radial artery. The ulnar artery also contributes through an anastomosis. This is in contrast to the superficial palmar arch, which is formed predominantly by the ulnar artery.
The princeps pollicis artery, or principal artery of the thumb, arises from the radial artery just as it turns medially towards the deep part of the hand; it descends between the first dorsal interosseous muscle and the oblique head of the adductor pollicis, along the medial side of the first metacarpal bone to the base of the proximal phalanx, where it lies beneath the tendon of the flexor pollicis longus muscle and divides into two branches.
Most of the dorsal metacarpal arteries arise from the dorsal carpal arch and run downward on the second, third, and fourth dorsal interossei of the hand and bifurcate into the dorsal digital arteries. Near their origin, they anastomose with the deep palmar arch by perforating arteries. They also anastomose with common palmar digital arteries, also via perforating arteries.
In anatomy, arterial tree is used to refer to all arteries and/or the branching pattern of the arteries. This article regards the human arterial tree. Starting from the aorta:
The palmar carpal arch is a joining of an artery to an artery, a circulatory anastomosis, known as an arterio-arterial anastomosis. The two connected arteries are the palmar carpal branch of the radial artery and the palmar carpal branch of the ulnar artery.
The dorsal carpal branch of the radial artery is a small vessel which arises beneath the extensor tendons of the thumb; crossing the carpus transversely toward the medial border of the hand, it anastomoses with the dorsal carpal branch of the ulnar artery.
The muscles of the thumb are nine skeletal muscles located in the hand and forearm. The muscles allow for flexion, extension, adduction, abduction and opposition of the thumb. The muscles acting on the thumb can be divided into two groups: The extrinsic hand muscles, with their muscle bellies located in the forearm, and the intrinsic hand muscles, with their muscles bellies located in the hand proper.
