M. widest Ridge (latissimusdorsi):
Pp: vertebral part (pars vertebralis) – spiny appendages of the lower six thoracic vertebrae, lumbar vertebrae, medial crest K. sacral. Iliac part (pars iliaca) – the medial segment of the iliac crest. Rib part (pars costalis) – the outer surface of the lower 3-4 ribs. Scapular part (pars scapularis) – the lower angle of the scapula. All fibers converge to the side and up to the armpit. In the final course it is accompanied by M.obly greater. Between the tendons of both muscles there is a subclavian calyx m. the widest ridge. This muscle forms the posterior limitation of the axillary fossa.
PK: crest of the humerus minor from the medial and anterior sides.
Function: works mainly on the shoulder joint-brings, converts, buttocks shoulder. With a calm contraction, it lifts the lower ribs, is an auxiliary respiratory muscle. During
with a quick, short contraction, the lateral part of the muscle compresses the ribs-it then interacts with the exhalation muscles during coughing and expectoration. With fixed arms, e.g. when hanging on a bar, together with the larger thoracic lift the torso up.
Nervous system: brachial plexus-N. thoracic-dorsal.