Unterarmknochen/en

Radius and ulna are the human forearm bones (lat. Ossa antebrachii) and are therefore located in the free upper extremity. They belong to the tubular bones. They are limited by the humerus and the carpal bones. The elbow joint and wrist are formed at these points.

Exercises

Lower extremity

Forearm bones

Related structures

Ulna

Radius

Body regions

Bones upper extremity

Upper extremity

Organ system

Tubular bones

Bones

Passive movement apparatus

Movement apparatus

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Anatomy

Anatomy of the forearm bones

The forearm bones are formed from the parallel tubular bones: Ulna and radius. The ulna is located in the medial side of the forearm. The radius is parallel to the ulna and has a thicker diameter. The two bones are connected by the membrana interossea antebrachii. If the forearm is in supination position (palm of the hand points forward in hanging arm position), the forearm bones are parallel. In the pronation position (palm of the hand points backwards in the hanging arm position), however, the parallelism of the bones is no longer present. The ulna and the radius cross each other.

Function

The forearm bones create a connection between the upper arm and the hand. The two forearm bones form joints with the upper arm bone and the carpal bones. The ulna and the radius allow the rotation of the arm by crossing the bones when changing from supination to pronation position.

Diseases

• fracture of the forearm

Free exploration

Look at the structure of the forearm bone in 3D and explore it freely. Afterwards you can test your acquired knowledge by the exercises.

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Exercises

Further article

Lower leg bones

Hand bones

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