Heart

• Pulmonary circulation moves blood between the heart and the lungs, transporting deoxygenated blood to the lungs to absorb oxygen and release carbon dioxide, and then flows back to the heart.
• Systemic circulation moves blood between the heart and the rest of the body, sending oxygenated blood out to cells and returning deoxygenated blood to the heart.
• The heart is the center of the Cardiovascular System, a hollow, cone-shaped muscular organ that pumps the blood to both pulmonary and systemic circulation, about the size of a person’s closed fist, and weighs about 300g in adults.
• The heart rests on the diaphragm, occupies the mediastinum, and 2/3 of its mass lies to the left side of the body’s midline.
• The systemic vessels, which transport blood from the left ventricle of the heart through all parts of the body and back to the right atrium, perform various functions such as carrying blood, exchanging nutrients, waste products, gases within tissues, transporting substances, regulating blood pressure, and directing blood flow to tissues.
• Arteries carry blood away from the heart, have thick walls with a lot of elastic tissue, and are the largest in diameter and thickest walls, examples include the aorta and pulmonary trunk.
• Pulmonary trunk carries blood from right ventricle towards lung, and pulmonary veins exit lungs and carry O2 rich blood to left atrium.
• Muscular arteries are medium to small in size, thick in diameter, contain smooth muscle cells, and can control blood flow to body regions.
• Capillaries exchange occurs between blood and tissue fluids, blood flows from arterioles into capillaries, capillaries branch to form networks, and blood flow is regulated by smooth muscle cells, precapillary sphincters.
• Valves are present in veins, and in the pulmonary circulation, blood vessels carry blood from right ventricle to lungs and back from left atrium of heart.
• Major arteries are part of the systemic circulation, which carries blood from the left ventricle to the tissues of the body and back to the right atrium.
• Oxygenated blood from the pulmonary veins passes from the left atrium into the left ventricle and from the left ventricle into the aorta.
• Capillary network structure is complex, with three tunics present in small veins, medium sized veins collect blood from small veins and deliver to large veins, and large veins contain valves.
• The apex of the heart is pointed and tilted towards the left hip, located at the 5th Intercostal Space, Midclavicular Line.
• The base of the heart is wider and the upper posterior margin.
• The Inferior vena cava returns blood from the abdomen, pelvis, lower limbs and empties into the right atrium of the heart.
• The Internal iliac arteries, division of the common iliac artery, supply blood to the pelvic area.
• The Internal jugular vein drains blood from the brain, face, neck and empties into the subclavian veins.
• The Hepatic arteries supply blood to the liver.
• The Renal arteries supply blood to the kidneys.
• The Subclavian veins form the brachiocephalic veins and join to form the superior vena cava.
• The Superior mesenteric arteries supply blood to the small intestines and upper portion of the colon.
• Abdominal Aorta Branches include the Celiac trunk arteries which supply blood to the stomach, pancreas, spleen, liver, and upper duodenum.
• The Veins of the Upper Limbs include the Brachial veins which empty into the axillary vein, the Cephalic veins which empty into the axillary vein and basilic vein, and the Median cubital veins which connects to the cephalic vein near the elbow.
• The Femoral arteries supply blood to the thigh.
• The External iliac arteries, division of the common iliac artery, supply blood to the lower limbs.
• In the pulmonary circulation, the blood returning to the heart in the pulmonary veins is oxygenated.
• The Ovarian arteries supply blood to the ovaries.
• The Popliteal arteries supply blood to the knee.
• The Common iliac arteries branch from the abdominal aorta and divide into the external and internal iliac arteries.
• The Lumbar arteries supply blood to the lumbar vertebra and back muscles.
• The Veins of the Head and Neck include the External jugular vein which drains blood from the head and neck and empties into the subclavian veins, and the Internal jugular vein which drains blood from the brain, face, neck and empties into the subclavian veins.
• The Fibular arteries supply blood to the lateral leg and foot.
• The Inferior mesenteric arteries supply blood to the colon.
• The Anterior and posterior arteries supply blood to the leg and foot.
• The External jugular vein drains blood from the head and neck and empties into the subclavian veins.
• The Inferior phrenic arteries supply blood to the diaphragm.
• The Testicular arteries supply blood to the testes.
• In the systemic circulation, the blood returning to the heart is deoxygenated.
• The Veins return blood to the heart.