Electrical conduction in the heart controlled by pacemaker cells in the sinoatrial node. Cross-section of human heart. cardiovascular system Heart and Brain Heart anatomy, 19th Century illustration Blood clot, SEM Heart attack, artwork Red blood cells and molecules, artwork Cardiovascular system, historical artwork Pulmonary veins and arteries. circulation, cardiovascular system Arterial supply and venous drainage of the organs. Anatomy of human body and circulatory system, front view Blood cells in blood vessel, artwork Veins of the posterior abdominal wall. cardiovascular system Veins and nerves of the neck. cardiovascular system, nervous system Arteries of the posterior abdominal wall. cardiovascular system Human upper body showing bones, lungs and circulatory system Human head with bone, muscles and circulatory system Human body showing heart and main circulatory system position Heart with arteries showing cholesterol in one and plaque in the other Build-up of atherosclerotic plaque in an artery Internal view of the human heart Arterial embolism Transverse section of an artery. cardiovascular system, circulatory system Superficial arteries and veins of face and scalp. cardiovascular system Anatomy diagram showing crucial veins in human head and neck Microscopic view of blood clotting inside the artery Human foot anatomy showing skin, veins, arteries, muscles and bones Anatomy of human circulatory system Microscopic view of white blood cells inside blood vessel Blood vessel anatomy Cross section of human heart Heart anatomy, 19th Century illustration Heart anatomy, 19th Century illustration Heart anatomy, 18th century Human heart, artwork Illustration of coronary artery atherosclerosis Human heart, artwork Heart disease, artwork Cut artery, artwork Coronary artery disease Blood vessel Artwork of the respiratory system of an asthmatic Artwork of lung oedema in heart failure Artwork of cerebral embolism, cause of stroke Artwork of bronchodilator action in asthma Structure of a human heart, artwork Circulatory system and brain, artwork Circulatory system and brain, artwork Page 2