yläraajaan

Yläraaja is the Finnish term for the upper limb. It encompasses all the structures that extend from the shoulder to the tip of the hand. This includes the shoulder girdle, the arm, the forearm, and the hand. The shoulder girdle, composed of the clavicle (collarbone) and scapula (shoulder blade), connects the upper limb to the axial skeleton.

The arm proper is the region between the shoulder and the elbow, containing the humerus bone and muscles like the biceps and triceps. The elbow joint is a hinge joint that allows for flexion and extension. The forearm, situated between the elbow and the wrist, contains the radius and ulna bones. These bones articulate at both the elbow and the wrist, enabling pronation and supination of the forearm, which are crucial for manipulating objects.

The wrist is the complex joint connecting the forearm to the hand, formed by the distal ends of the radius and ulna and the carpal bones. The hand itself is a highly dexterous and intricate structure, comprising the carpal bones (wrist), metacarpal bones (palm), and phalanges (fingers and thumb). The opposable thumb is a key feature, allowing for precise grip and manipulation of objects, a fundamental aspect of human dexterity and tool use. The vascularization of the upper limb is provided by the subclavian artery, which becomes the axillary and then the brachial artery. Venous drainage follows a similar path. Innervation is primarily from the brachial plexus, a network of nerves originating from the spinal cord. The primary function of the upper limb is to allow for a wide range of movements, including reaching, grasping, lifting, and fine motor control.