Radius and ulna – Anatomy Atlas

Table of Contents

Overview

Radius and ulna Like all long bones, the radius and ulna both have a head, a body or shaft, articulating surfaces and a number of ‘bumps and grooves’ that serve as attachment points for muscles and connective tissue, or pathways for nerves, vessels and tendons. The head of the radius is located at the bone’s proximal end. It is small and circular, and contributes to formation of the humeroradial joint (of the elbow) with the capitulum of the humerus. It also forms the proximal radioulnar joint with the radial notch of the ulna. The distal end of the radius is enlarged for articulation with both the ulna (distal radioulnar joint) and with the carpal bones at the wrist (radiocarpal joint). Unlike the radius, the head of the ulna is located at the bone’s distal aspect; it articulates with the radius at the distal radioulnar joint and does not participate in forming the wrist joint. The proximal end of the ulna, the olecranon, is shaped like a hook; this projection hinges around the trochlea at the distal end of the humerus forming the humeroulnar joint of the elbow. Browse the atlas to learn the specific features of the radial and ulna bones.

Keypoints

Key points about the radius and ulna
Bony landmarks of radius	Head, neck, articular circumference of head, articular facet of head, body, anterior border, posterior border, interosseous border, radial tuberosity, pronator tuberosity, suprastyloid crest, styloid process, dorsal radial tubercle, carpal articular surface
Bony landmarks of ulna	Olecranon, trochlear notch, coronoid process, tuberosity of ulna, radial notch, sublime tubercle, body, anterior border, posterior border, interosseous border, head
Ligaments	Interosseous membrane of forearm Oblique cord Annular ligament of radius Radial collateral ligament of elbow joint Ulnar collateral ligament of elbow Dorsal radioulnar ligament Palmar radioulnar ligament