The _______ is the muscular wall that makes up the bulk of the heart. The _______ ventricle is the thicker and larger ventricle. The atrium and ventricle of each side are connected by a/an _______valve. A single cardiac cycle consists of the simultaneous contractions of both _______ followed by the simultaneous contractions of both _______. The heart supplies blood to itself via _______ arteries. Contraction of the ventricles (and relaxation of the atria) is called _______, whereas relaxation of the ventricles is called _______. The heart pumps blood to the lungs for oxygenation via the pulmonary _______.