digplanet beta 1: Athena
Share digplanet:

Agriculture

Applied sciences

Arts

Belief

Business

Chronology

Culture

Education

Environment

Geography

Health

History

Humanities

Language

Law

Life

Mathematics

Nature

People

Politics

Science

Society

Technology

Humerus
Humerus - anterior view.png
Position of humerus (shown in red). Anterior view.
Illu upper extremity.jpg
Details
Latin Humerus
Identifiers
Gray's p.209
MeSH A02.835.232.087.090.400
TA A02.4.04.001
FMA FMA:13303
Anatomical terms of bone

The humerus (/ˈhjmərəs/, Plural: humeri) is a long bone in the arm or forelimb that runs from the shoulder to the elbow.

It connects the scapula and the two bones of the lower arm, which consists of the radius and ulna, and consists of three sections. The upper extremity consists of a rounded head, a narrow neck, and two short processes (tubercles, sometimes called tuberosities). Its body is cylindrical in its upper portion, and more prismatic below. The lower extremity consists of 2 epicondyles, 2 processes (trochlea & capitulum), and 3 fossae (radial fossa, coronoid fossa, and olecranon fossa). As well as its true anatomical neck, the constriction below the greater and lesser tubercles of the humerus is referred to as its surgical neck due to its tendency to commonly get fractured, thus often becoming the focus of surgeons.

Structure[edit]

Articulations[edit]

At the shoulder, the head of the humerus articulates with the glenoid fossa of the scapula. More distally, at the elbow, the capitulum of the humerus articulates with the head of the radius, and the trochlea of the humerus articulates with the trochlear notch of the ulna.

Diagram of the human shoulder joint 
The left shoulder and acromioclavicular joints, and the proper ligaments of the scapula. 
Head of humerus 
The supinator

Nerves[edit]

The axillary nerve is located at the proximal end, against the shoulder girdle. Dislocation of the humerus's glenohumeral joint, has the potential to injure the axillary nerve or the axillary artery. Signs and symptoms of this dislocation include a loss of the normal shoulder contour and a palpable depression under the acromion.

The radial nerve follows the humerus closely. At the midshaft of the humerus, the radial nerve travels from the posterior to the anterior aspect of the bone in the spiral groove. A fracture of the humerus in this region can result in radial nerve injury.

The ulnar nerve at the distal end of the humerus near the elbow is sometimes referred to in popular culture as 'the funny bone'. Striking this nerve can cause a tingling sensation ("funny" feeling), and sometimes a significant amount of pain. It lies posterior to the medial epicondyle, and is easily damaged in elbow injuries.[1]

Horizontal section at the middle of upper arm
Horizontal section of upper arm. 
Humerus 

Function[edit]

Muscular attachment[edit]

The deltoid originates on the lateral third of the clavicle, acromion and the crest of the spine of the scapula. It is inserted on the deltoid tuberosity of the humerus and has several actions including abduction, extension, and circumduction of the shoulder. The supraspinatus also originates on the spine of the scapula. It inserts on the greater tubercle of the humerus, and assists in abduction of the shoulder.

The pectoralis major, teres major, and latissimus dorsi insert at the intertubercular groove of the humerus. They work to adduct and medially, or internally, rotate the humerus.

The infraspinatus and teres minor insert on the greater tubercle, and work to laterally, or externally, rotate the humerus. In contrast, the subscapularis muscle inserts onto the lesser tubercle and works to medially, or internally, rotate the humerus.

The biceps brachii, brachialis, and brachioradialis (which attaches distally) act to flex the elbow. (The biceps do not attach to the humerus.) The triceps brachii and anconeus extend the elbow, and attach to the posterior side of the humerus.

The four muscles of supraspinatus, infraspinatus, teres minor and subscapularis form a musculo-ligamentous girdle called the rotator cuff. This cuff stabilizes the very mobile but inherently unstable glenohumeral joint. The other muscles are used as counterbalances for the actions of lifting/pulling and pressing/pushing.

Left humerus. Anterior view.
Humerus ant (mirroed).png Left humerus - anterior view.png Left humerus - close-up - animation - stop at anterior view.gif HumerusFront.png Gray207.png Human left humerus - anterior view - muscles.svg A. Supraspinatus muscle
B. Latissimus dorsi muscle
C. Pectoralis major muscle
D. Deltoid muscle
E. Brachioradialis
F. Extensor carpi radialis longus muscle
G. Common extensor tendon
H. Subscapularis muscle
I. Teres major muscle
J. Coracobrachialis muscle
K. Brachialis muscle
L. Pronator teres muscle
M. Common flexor tendon


Left humerus. Posterior view.
Humerus post (mirroed).png Left humerus - posterior view.png Left humerus - close-up - animation - stop at posterior view.gif HumerusBack.png Gray208.png


Clinical significance[edit]

Fracture[edit]

Main article: Humerus fracture

Other animals[edit]

Primitive fossil amphibians had little, if any, shaft connecting the upper and lower extremities, making their limbs very short. In most living tetrapods, however, the humerus has a similar form to that of humans. In many reptiles and some primitive mammals, the lower extremity includes a large foramen, or opening, into which nerves and blood vessels pass.[2]

History[edit]

The word "humerus" is derived from Latin: humerus, umerus meaning upper arm, shoulder, and is linguistically related to Gothic ams shoulder and Greek ōmos.[3]

Additional images[edit]

References[edit]

This article incorporates text from a public domain edition of Gray's Anatomy.

  1. ^ http://teachmeanatomy.net/upper-limb-2/bones/the-humerus/
  2. ^ Romer, Alfred Sherwood; Parsons, Thomas S. (1977). The Vertebrate Body. Philadelphia, PA: Holt-Saunders International. pp. 198–199. ISBN 0-03-910284-X. 
  3. ^ Harper, Douglas. "Humerus". Online Etymology Dictionary. Retrieved 6 November 2014. 

External links[edit]


Original courtesy of Wikipedia: http://en.wikipedia.org/wiki/Humerus — Please support Wikipedia.
This page uses Creative Commons Licensed content from Wikipedia. A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia.

6038 news items

 
BreakingNews.ie
Fri, 31 Oct 2014 10:48:45 -0700

Weatherman Jude Redfield absolutely nailed his Halloween weather report this morning with a close-to-the-bone segment. The weathercaster delivered his October 31 weather report from Kentucky with a comedic slant, but kept his head in the game despite ...

FDRMX

FDRMX
Wed, 19 Nov 2014 13:00:00 -0800

Today's new developments detail (TW: medical gore) his injuries as “a facial fracture involving the orbit of his eye, three separate fractures of his left shoulder blade, and a fracture of his left humerus bone in his upper arm.” His arm in particular ...
 
Colonnade (subscription)
Fri, 21 Nov 2014 11:30:00 -0800

The crash resulted in five hours of surgery and a broken bone that required three metal plates and 18 screws to mend it. He also suffered a facial fracture, three separate fractures in his shoulder blade and his left humerus shattered in six places. U2 ...

ABC News

Pueblo Chieftain
Fri, 21 Nov 2014 15:26:15 -0800

FILE - In this Nov. 6, 2014 file photo, Entertainer Bill Cosby gestures during an interview about the upcoming exhibit, Conversations: African and African-American Artworks in Dialogue, at the Smithsonian's National Museum of African Art, in Washington.

Philly.com

Philly.com
Thu, 20 Nov 2014 23:52:30 -0800

Morgan, who turns 25 in February, had surgery last January to close a gap in the front of his shoulder that was catching the top of the humerus bone. He missed the entire 2014 season, but appeared in September instructional league games before logging ...
 
New Zealand Herald
Fri, 21 Nov 2014 14:30:00 -0800

Lying behind a hospital waiting room curtain at 1.30am with a shattered humerus sticking menacingly through the skin of your upper arm is no day at the beach. Particularly when you're refused painkillers. You don't forget those things. Outside the ...
 
Pueblo Chieftain
Fri, 21 Nov 2014 07:22:30 -0800

I'd much rather take my chances and not let some doctor wearing latex gloves stab my humerus with a needle. I do not find that very humorous. I imagine at like $20 bucks a pop or whatever, they are pretty good for the vaccine producers. I want a ...
 
Pueblo Chieftain
Fri, 21 Nov 2014 07:22:30 -0800

I'd much rather take my chances and not let some doctor wearing latex gloves stab my humerus with a needle. I do not find that very humorous. I imagine at like $20 bucks a pop or whatever, they are pretty good for the vaccine producers. I want a ...
Loading

Oops, we seem to be having trouble contacting Twitter

Support Wikipedia

A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia. Please add your support for Wikipedia!

Searchlight Group

Digplanet also receives support from Searchlight Group. Visit Searchlight