Triceps Brachii Muscle - Human Anatomy - Origins

Origins

The long head arises from the infraglenoid tubercle of the scapula. It extends distally anterior to the teres minor and posterior to the teres major.

The medial head arises distally from the groove of the radial nerve; from the dorsal (back) surface of the humerus; from the medial intermuscular septum; and its distal part also arises from the lateral intermuscular septum. The medial head is mostly covered by the lateral and long heads, and is only visible distally on the humerus.

The lateral head arises from the dorsal surface of the humerus, lateral and proximal to the groove of the radial nerve, from the greater tubercle down to the region of the lateral intermuscular septum.

Each of the three fascicles has its own motorneuron subnucleus in the motor column in the spinal cord. The medial head is formed predominantly by small type I fibers and motor units, the lateral head of large type IIb fibers and motor units and the long head of a mixture of fiber types and motor units. It has been suggested that each fascicle "may be considered an independent muscle with specific functional roles."

Read more about this topic:  Triceps Brachii Muscle, Human Anatomy

Other articles related to "origins, origin":

Yale - History - Origins
... Originally called the "Collegiate School", the institution opened in the home of its first rector, Abraham Pierson, in Killingworth (now Clinton) ... The school moved to Saybrook, and then Wethersfield ...
Lepidoptera - Etymology
... The origins of the common names "butterfly"and "moth" are varied and often obscure ... Other than that, the origin is unknown, although it could be derived from the pale yellow color of many species' wings suggesting the color of butter ... The origins of the English word moth are more clear, deriving from the Old English moððe" (cf ...
Zanja Madre - Origins
... The Zanja Madre was placed at a location close to present-day Broadway Street at the foot of the Elysian Hills by the river ... An earth and brush dam, called a toma, was created to pool up the water into the ditch which then ran along an elevated slope down to the pueblo after which it was split into multiple ditches which ran to the various portions of lowland ...
X-Men Origins: Wolverine
... X-Men Origins Wolverine is a 2009 American superhero film based on the Marvel Comics' fictional character Wolverine ... X-Men Origins Wolverine was released worldwide on May 1, 2009 and their reviews were generally unfavorable, with critics considering the film and its screenplay uninspired, but ...

Famous quotes containing the word origins:

    Grown onto every inch of plate, except
    Where the hinges let it move, were living things,
    Barnacles, mussels, water weeds—and one
    Blue bit of polished glass, glued there by time:
    The origins of art.
    Howard Moss (b. 1922)

    The origins of clothing are not practical. They are mystical and erotic. The primitive man in the wolf-pelt was not keeping dry; he was saying: “Look what I killed. Aren’t I the best?”
    Katharine Hamnett (b. 1948)

    The settlement of America had its origins in the unsettlement of Europe. America came into existence when the European was already so distant from the ancient ideas and ways of his birthplace that the whole span of the Atlantic did not widen the gulf.
    Lewis Mumford (1895–1990)