In human body , the bicep, or simply biceps in common parlance, is, as the name implies, a two-headed muscle located on the upper arm.Rectus abdominis The human rectus abdomnin.mucel.. Latin musculus rectus abdominis Gray's subject OriginpubisInsertion Costal cartilage of ribs 5-7, xiphoi process of sternumArteryinferior epigastric arteryNerve segmentally by thoraco-abdominal nerves (T7 to T12) Actions Flexion of the lumbar spine AntagonistErector spinae The rectus abdominis muscle, also known as the "six pack", is a paired muscle running vertically on each side of the anterior wall of the human abdomen