Humerus

Description

Humerus is a long bone which consists of a shaft (diaphysis) and two extremities (epiphysis). It is the longest bone of the upper extremity. It's name comes from the word "humorous" because when hitting it at the ulnar nerve it gives a strange "kind of funny" feeling.

Structure

Upper Extremity Features

The head (caput humeri) is the articular surface of the upper extremity, which is an irregular hemisphere.

The anatomical neck is the part between the head and the tuberosities.

The surgical neck is the part between the tuberosities and the shaft.

The greater tuberosity it is located lateral to the head.

The lesser tuberosity is located inferior to the head, on the anterior part of the humerus, Its very prominent and palpable.

Bicipital (intertubercular) groove is located between the two tuberosities. The Biceps tendon is placed here.

Body Features

The body of the humerus has three borders and three surfaces.

Borders

1. Anterior
2. Lateral
3. Medial

Surfaces

1. Antero-lateral
2. Antero-medial
3. Posterior

Function

The Humerus serves as an attachment to 13 Muscles and 3 very important Nerves, which control the functions of hand and elbow, pass through the humerus.

Articulations

Articulatio Humeri

Articulatio Cubiti

Muscle Attachments

Muscle	Attachment
Supraspinatus	Greater Tubercle
Infraspinatus	Greater Tubercle
Teres Minor	Greater Tubercle Upper Part of the Lateral Border
Subscapularis	Lesser Tubercle
Pectoralis Major	Upper Part of the Anterior Border
Triceps Brachii	Lower Part of the Lateral Border Lateral Supracondylar Ridge
Brachioradialis	Lateral Supracondylar Ridge
Extensor Carpi Radialis Longus	Lateral Supracondylar Ridge
Teres Major	Crest of the Lesser Tubercle
Coracobrachialis	Crest of the Lesser Tubercle
Brachialis	Medial Supracondylar Ridge
Pronator Teres	Medial Supracondylar Ridge
Latissimus Dorsi	Bicipital Groove

References

Gray H., 2000, Anatomy of Human Body, Twentieth Edition, New York, Bartleby.com

Liridona Dervishi