antebraço

Antebraço is the region of the upper limb between the elbow and the wrist. It is composed of two long bones, the radius and the ulna, which articulate with each other and with the humerus at the elbow and with the carpal bones at the wrist. The forearm contains numerous muscles responsible for movements of the wrist, hand, and fingers, as well as supination and pronation of the forearm.

The muscles of the forearm are typically divided into anterior and posterior compartments, separated by the interosseous membrane. The anterior compartment muscles are primarily responsible for flexion of the wrist and fingers and pronation of the forearm. These include the pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris, flexor digitorum superficialis, flexor digitorum profundus, and flexor pollicis longus. The posterior compartment muscles are mainly responsible for extension of the wrist and fingers and supination of the forearm. These include the brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris, and supinator.

The radius is the lateral bone of the forearm when in anatomical position, while the ulna is the medial bone. The radius articulates with the capitulum of the humerus and the radial notch of the ulna. The ulna articulates with the trochlea of the humerus and the radial notch of the radius. The interosseous membrane is a strong fibrous sheet that connects the shafts of the radius and ulna, providing stability to the forearm and serving as an attachment site for muscles.

Nerves such as the median, ulnar, and radial nerves pass through the forearm, innervating the muscles and providing sensory information to the skin. Blood supply is mainly provided by the radial and ulnar arteries, which are branches of the brachial artery. The forearm plays a crucial role in a wide range of daily activities, from fine motor tasks like writing to gross motor movements like lifting and throwing.