Upper extremity of humerus
You don't need to be Editor-In-Chief to add or edit content to WikiDoc. You can begin to add to or edit text on this WikiDoc page by clicking on the edit button at the top of this page. Next enter or edit the information that you would like to appear here. Once you are done editing, scroll down and click the Save page button at the bottom of the page.
| Bone: Upper extremity of humerus | |
|---|---|
 | |
| Left humerus. Anterior view. | |
 | |
| Left humerus. Posterior view. | |
| Gray's | subject #51 209 |
The upper extremity of the humerus (proximal humerus) consists of a large rounded head joined to the body by a constricted portion called the neck, and two eminences, the greater and lesser tubercles.
The head (caput humeri)
The head, nearly hemispherical in form, is directed upward, medialward, and a little backward, and articulates with the glenoid cavity of the scapula. The circumference of its articular surface is slightly constricted and is termed the anatomical neck, in contradistinction to a constriction below the tubercles called the surgical neck which is frequently the seat of fracture.
The anatomical neck
The Anatomical Neck (collum anatomicum) is obliquely directed, forming an obtuse angle with the body. It is best marked in the lower half of its circumference; in the upper half it is represented by a narrow groove separating the head from the tubercles. It affords attachment to the articular capsule of the shoulder-joint, and is perforated by numerous vascular foramina. Fracture of the anatomical neck rarely occurs.
The anatomical neck of the humerus is an indentation distal to the head of the humerus on which the articular capsule attaches.
The greater tubercle
('tuberculum majus; greater tuberosity') The greater tubercle is situated lateral to the head and lesser tubercle, and just lateral to the anatomical neck. Its upper surface is rounded and marked by three flat impressions: the highest of these gives insertion to the supraspinatus muscle; the middle to the infraspinatus muscle; the lowest one, and the body of the bone for about 2.5 cm. below it, to the teres minor muscle. The lateral surface of the greater tubercle is convex, rough, and continuous with the lateral surface of the body.
The lesser tubercle
('tuberculum minus; lesser tuberosity') The lesser tubercle, although smaller, is more prominent than the greater: it is situated in front, and is directed medialward and forward. Above and in front it presents an impression for the insertion of the tendon of the subscapularis muscle.
The intertubercular (bicipital) groove
The tubercles are separated from each other by a deep groove, the intertubercular groove (bicipital groove), which lodges the long tendon of the biceps brachii muscle and transmits a branch of the anterior humeral circumflex artery to the shoulder-joint. It runs obliquely downward, and ends near the junction of the upper with the middle third of the bone. In the fresh state its upper part is covered with a thin layer of cartilage, lined by a prolongation of the synovial membrane of the shoulder-joint; its lower portion gives insertion to the tendon of the latissimus dorsi muscle. It is deep and narrow above, and becomes shallow and a little broader as it descends. Its lips are called, respectively, the crests of the greater and lesser tubercles (bicipital ridges), and form the upper parts of the anterior and medial borders of the body of the bone.
The surgical neck
The surgical neck is a narrow area distal to the tubercles that is a common site of fracture. It makes contact with the axillary nerve and the posterior humeral circumflex artery.
Additional images
 The left shoulder and acromioclavicular joints, and the proper ligaments of the scapula. |
This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.
External links
bn:প্রগণ্ডাস্থির উর্ধ্ব প্রান্ত
Acknowledgement and Attribution Regarding Sources of Content
Some of the initial content on this page may be incorporated in part from copyleft sources in the public domain including wikis such as Wikipedia and AskDrWiki. Drug information for patients came from the The National Library of Medicine. Infectious disease information may have come from the Centers for Disease Control (CDC). Differential Diagnoses are drawn from clinicians as well as an amalgamation of 3 sources: 1.The Disease Database; 2. Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:3; 3. Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:7 .
