The musculophrenic artery is a terminal branch of the internal thoracic artery and has similar embryologic origins. During the end of the 3rd week of development, vasculogenesis occurs from the posterolaterally located paraxial mesoderm. Vessels form between developing somites and join with the dorsal aorta to form intersegmental arteries. Around the 7th week, the internal thoracic artery is formed when the longitudinal branches of the intersegmental arteries from the dorsal aorta become linked via longitudinal anastomosing channels and lose their connection to the aorta. During this process of anastomosis, the musculophrenic artery is also formed (Standring 2016).