M. pectoralis: 

Simic and Andrejevic (1963, 1964) recognize Pars sternobra­chialis and Pars costo ("thoraco-") brachialis with separate proximal attachments on the sternum and thoracic ribs, respectively, but a common insertion on Crista delto­ pectoralis (Ost . Anno . 184). Other studies of these parts indicate different fiber orientations and innervation patterns by two distinct branches from the ventral cord of the brachial plexus (see Rosser and George, 1986; Dial, et al., 1987; Kaplan and Goslow, 1989; Sokoloff, et al., 1989).

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