They have an elongate manubrium composed of four oral arms. Four gonads lie in this main body structure, or "manubrium". The sternal angle is located at the point where the body joins the manubrium. Its three regions are the manubrium, the body, and the xiphoid process. Medially, it articulates with the manubrium of the sternum (breastbone) at the sternoclavicular joint. Food travels through the muscular manubrium while the radial canals help disperse the food. This pulls the manubrium of the malleus inwards and tightens it. In this example, the rib articulates with the manubrium via the costal cartilage. The manubrium is attached directly to the subumbrella. Below, the fascia is attached to the thoracic outlet (acromion, clavicle, and manubrium). The upper border is oval and articulates with the manubrium, at the sternal angle. The clavicle articulates with the manubrium to form the anterior border of the thoracic inlet. Sternoclavicularis from manubrium to clavicle between pectoralis major and coracoclavicular fascia. Their gonads are on the manubrium ("handle"). The manubrium is cross-shaped with lancet-shaped lips.