Brachialis muscle 232784 221323954 2008-06-24T00:54:31Z 72.93.103.168 {{Copyedit|date=March 2008}} {{Muscle infobox | Name = Brachialis | Latin = musculus brachialis | GraySubject = 124 | GrayPage = 444 | Image = Brachialis.png | Caption = Deep muscles of the chest and front of the arm, with the boundaries of the [[axilla]]. (Brachialis visible at bottom right.) | Image2 = Gray413 color.png | Caption2 = Cross-section through the middle of upper arm. (Brachialis labeled at center left.) | Origin = anterior surface of the [[humerus]], particularly the distal half of this bone | Insertion = [[Coronoid_process_of_the_ulna|coronoid process]] and the [[tuberosity of the ulna]] | Blood = [[radial recurrent artery]]| Nerve = [[musculocutaneous nerve]] | Action = [[flexion]] at [[elbow|elbow joint]] | MeshName = | MeshNumber = | DorlandsPre = m_22 | DorlandsSuf = 12548498 | }} The '''brachialis''' ('''brachialis anticus''') is a [[muscle]] in the upper [[arm]] that flexes the [[elbow|elbow joint]]. It lies just deep to [[biceps brachii]], and is a more powerful flexor of the elbow. It makes up part of the floor of the region known as the [[cubital fossa]]. ==Origin and insertion== The brachialis originates from the lower half of the front of the [[humerus]], near the insertion of the [[deltoid muscle]], which it embraces by two angular processes. Its origin extends below to within 2.5 cm. of the margin of the articular surface of the humerus at the elbow joint. It also arises from the [[intermuscular septa]] of the arm, but more extensively from the medial than the lateral; it is separated from the lateral below by the [[brachioradialis]] and [[extensor carpi radialis longus]] muscles. Its fibers converge to a thick tendon, which is inserted into the tuberosity of the [[ulna]] and the rough depression on the anterior surface of the [[coronoid process of the ulna]]. ==Innervation== The brachialis muscle is innervated by the [[musculocutaneous nerve]], which runs on its superficial surface, between it and the [[biceps brachii]]. Part of it is also innervated by the [[radial nerve]] which allows it to be split during certain approaches to the arm. The divide between the two innervations is at the insertion of the deltoid. ==Actions== The brachialis is the strongest flexor of the elbow. Unlike the biceps, the brachialis does not insert on the radius, and therefore cannot participate in [[pronation]]/[[supination]] of the forearm. Pronation/supination of the [[forearm]] does not affect its action. ==Variations== Occasionally doubled; additional slips to the [[supinator]], [[pronator teres]], [[biceps brachii]], [[lacertus fibrosus]], or [[Radius (bone)|radius]] are more rarely found. ==Additional images== <gallery> Image:Gray207.png|Left humerus. Anterior view. Image:Gray213.png|Bones of left forearm. Anterior aspect. Image:Nerves_of_the_left_upper_extremity.gif|Nerves of the left upper extremity. </gallery> ==External links== * {{MuscleLoyola|brac}} * {{MuscleUWash|brachialis}} * {{GPnotebook|-1777991623}} * {{Exrx|Muscles/Brachialis}} {{Gray's}} {{Muscles of upper limb}} [[Category:Muscles of the upper limb]] [[ar:عضلة عضدية]] [[cs:Hluboký sval pažní]] [[de:Musculus brachialis]] [[fr:Muscle brachial]] [[he:שריר הזרוע]] [[hr:Nadlaktični mišić]] [[la:Musculus brachialis]] [[hu:Felkari izom]] [[nl:Musculus brachialis]] [[ja:上腕筋]] [[pl:Mięsień ramienny]] [[pt:Músculo braquial]] [[ru:Брахиалис]] [[sl:Brahialna mišica]] [[sv:Brachialis]]