Brachialis muscle - wikipedia Brachialis muscle Brachialis Deep muscles of the chest and front of the arm, with the boundaries of the axilla. ( Brachialis visible at bottom right. ) Position of brachialis ( shown in red ). Details Origin anterior surface of the humerus, particularly the distal half of this bone Insertion coronoid process and the tuberosity of the ulna Artery radial recurrent artery, brachial artery Nerve musculocutaneous nerve ( C5 - C7 ) and radial nerve ( C5, C6 ) Actions flexion at elbow joint Identifiers Latin musculus brachialis TA A04. 6.02. 018 FMA 37667 Anatomical terms of muscle ( edit on Wikidata ) The brachialis ( brachialis anticus ) is a muscle in the upper arm that flexes the elbow joint. It lies deeper than the biceps brachii, and makes up part of the floor of the region known as the cubital fossa. The brachialis is the prime mover of elbow flexion. While the biceps brachii appears as a large anterior bulge on the arm and commands considerable interest among body builders, the brachialis underlying it actually generates about 50 % more power and is thus the prime mover of elbow flexion. Contents 1 Structure 1.1 Blood supply 1.2 Nerve supply 1.3 Variation 2 Function 3 History 3.1 Etymology 4 Additional images 5 See also 6 References 7 External links Structure The brachialis originates from the anterior surface of the distal half 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. 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. Blood supply The brachialis is supplied by the Muscular branches of brachial artery and the recurrent radial artery. Nerve supply The brachialis muscle is innervated by the musculocutaneous nerve, which runs on its superficial surface, between it and the biceps brachii. However, in 70 - 80 % of people, the muscle has double innervation with the radial nerve ( C5 - T1 ). The divide between the two innervations is at the insertion of the deltoid. Variation The muscle is occasionally doubled ; additional slips to the supinator, pronator teres, biceps brachii, lacertus fibrosus, or radius are more rarely found. ( A `` slip '' in this context refers to an accessory or variant part of a muscle that has an unusual trajectory in growth relative to the normal fibers ' direction of growth. ) Function. The brachialis flexes the arm at the elbow joint. Unlike the biceps, the brachialis does not insert on the radius, and does not participate in pronation and supination of the forearm. History Etymology The brachialis muscle and brachial muscle can be considered as the anglicized variant of the Latin expression musculus bracchialis. In classical Latin bracchialis means of or belonging to the arm, and is derived from classical Latin bracchium, `` arm ''. The expression musculus brachialis is used in the current official anatomic nomenclature Terminologia Anatomica. Additional images Position of brachialis ( shown in red ). Animation. Still image. Horizontal section through the middle of upper arm. ( Brachialis labeled at center left. ) Muscles of lower limb, including insertion of brachialis tendon. Cross section. ( Brachialis labeled at bottom left. ) Left humerus. Anterior view. Bones of left forearm. Anterior aspect. Nerves of the left upper extremity. Brachialis muscle ( labeled in green text ) See also This article uses anatomical terminology ; for an overview, see Anatomical terminology. References This article incorporates text in the public domain from page 444 of the 20th edition of Gray 's Anatomy ( 1918 ) ^ Jump up to : Saladin, Kenneth S, Stephen J. Sullivan, and Christina A. Gan. Anatomy & Physiology : The Unity of Form and Function. 2015. Print. ^ Jump up to : Drake, Richard L. ; Vogl, Wayne ; Tibbitts, Adam W.M. Mitchell ; illustrations by Richard ; Richardson, Paul ( 2005 ). Gray 's anatomy for students. Philadelphia : Elsevier / Churchill Livingstone. p. 662,672. ISBN 978 - 0 - 8089 - 2306 - 0. Jump up ^ `` Brachialis. '' UW Department of Radiology. University of Washington, Nov. 2005 Jump up ^ `` Brachialis Muscle. '' Kenhub. Kenhub, Aug. 2001 Jump up ^ Dirckx, J.H. ( Ed. ) ( 1997 ). Stedman 's concise medical dictionary for the health professions. ( 3rd edition ). Baltimore : Williams & Wilkins. Jump up ^ Anderson, D.M. ( 2000 ). Dorland 's illustrated medical dictionary ( 29th edition ). Philadelphia / London / Toronto / Montreal / Sydney / Tokyo : W.B. Saunders Company. Jump up ^ Triepel, H. ( 1910 ). Die anatomischen Namen. Ihre Ableitung und Aussprache. Mit einem Anhang : Biographische Notizen. ( Dritte Auflage ). Wiesbaden : Verlag J.F. Bergmann. ^ Jump up to : Lewis, C.T. & Short, C. ( 1879 ). A Latin dictionary founded on Andrews ' edition of Freund 's Latin dictionary. Oxford : Clarendon Press. Jump up ^ Federative Committee on Anatomical Terminology ( FCAT ) ( 1998 ). Terminologia Anatomica. Stuttgart : Thieme External links Wikimedia Commons has media related to Brachialis muscles. Illustration : brachialis from The Department of Radiology at the University of Washington Muscles / Brachialis at exrx.net Muscles of the arm Shoulder deltoid rotator cuff supraspinatus infraspinatus teres minor subscapularis teres major fascia : deltoid fascia supraspinous fascia infraspinous fascia Arm ( compartments ) anterior coracobrachialis biceps brachialis posterior triceps brachii anconeus articularis cubiti fascia axillary sheath axillary fascia brachial fascia intermuscular septa lateral medial other spaces quadrangular space triangular space triangular interval Forearm anterior superficial : pronator teres palmaris longus flexor carpi radialis flexor carpi ulnaris flexor digitorum superficialis deep : pronator quadratus flexor digitorum profundus flexor pollicis longus posterior superficial : mobile wad brachioradialis extensor carpi radialis longus and brevis extensor digitorum extensor digiti minimi extensor carpi ulnaris deep : supinator anatomical snuff box abductor pollicis longus extensor pollicis brevis extensor pollicis longus extensor indicis fascia bicipital aponeurosis common tendons extensor flexor antebrachial fascia other cubital tunnel Hand lateral volar thenar opponens pollicis flexor pollicis brevis abductor pollicis brevis adductor pollicis medial volar hypothenar opponens digiti minimi flexor digiti minimi brevis abductor digiti minimi palmaris brevis intermediate lumbrical interossei dorsal palmar fascia posterior : extensor retinaculum extensor expansion anterior : flexor retinaculum palmar aponeurosis Anatomy portal Retrieved from `` https://en.wikipedia.org/w/index.php?title=Brachialis_muscle&oldid=835485046 '' Categories : Wikipedia articles incorporating text from the 20th edition of Gray 's Anatomy ( 1918 ) Elbow flexors Muscles of the upper limb Hidden categories : All articles with unsourced statements Articles with unsourced statements from April 2018 Talk Contents About Wikipedia Български Català Čeština Dansk Deutsch Español فارسی Français Galego 한국어 Hrvatski Bahasa Indonesia Italiano עברית Latina Lietuvių Magyar Nederlands 日本 語 Polski Português Română Русский Slovenščina Suomi Svenska 中文 19 more Edit links This page was last edited on 8 April 2018, at 23 : 59 ( UTC ). 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Question: what is the action of the brachialis muscle
Answer: flexion at elbow joint