Circulatory System

Label heart diagram for numbers 1 – 7

Circulatory System Purpose: –To transport oxygen and food to all cells and then to retrieve waste products for elimination Includes: –The heart, the blood, and the vessels

Ready for Transplant Photograph by Robert Clark A human heart destined for transplant lies cradled in a TransMedics Organ Care System. The device can keep a heart warm and beating—and viable for many hours longer than the conventional method for handling donor hearts: immersion in a saline solution and packing in ice. National Geographic Feb. 2007

The Heart Located in the mediastinal cavity Located in the mediastinal cavity –Behind sternum, between the lungs Muscular, hollow organ Muscular, hollow organ –Size of a closed fist

The Heart Comprised of three layers of tissue Comprised of three layers of tissue –Endocardium- smooth layer of cells that lines inside of heart –Myocardium- muscular middle layer (thickest layer) –Pericardium- double-layered membrane or sac, that covers the outside of the heart

The Heart

Divided into four chambers Divided into four chambers –Upper chambers called atria –Lower chambers called ventricles Septum- muscular wall that separates the heart into a right side and a left side Septum- muscular wall that separates the heart into a right side and a left side

The Heart The right atrium receives blood as it returns from the body cells (this blood has very little oxygen, is dark red) The right atrium receives blood as it returns from the body cells (this blood has very little oxygen, is dark red) The right ventricle receives blood from the right atrium and pumps the blood into the pulmonary artery, which carries the blood to the lungs for oxygen The right ventricle receives blood from the right atrium and pumps the blood into the pulmonary artery, which carries the blood to the lungs for oxygen

The Heart The left atrium receives oxygenated blood from the lungs The left atrium receives oxygenated blood from the lungs The left ventricle receives blood from the left atrium and pumps the blood into the aorta for transport to the body cells The left ventricle receives blood from the left atrium and pumps the blood into the aorta for transport to the body cells –The left ventricle works 6 times harder than the right ventricle because it is responsible for giving the blood the push it needs to travel throughout the whole body

The Heart One-way valves keep blood flowing in the right direction One-way valves keep blood flowing in the right direction –Tricuspid valve- between the right atrium and the right ventricle –Pulmonary valve- between the right ventricle and the pulmonary artery –Mitral valve- between the left atrium and left ventricle –Aortic valve- between the left ventricle and the aorta

The Heart Although separated by the septum, both sides work together in a cyclic manner Although separated by the septum, both sides work together in a cyclic manner –Diastole- period of rest –Systole- period of ventricular contraction

Blood Vessels When blood leaves the heart, it is carried throughout the body in blood vessels When blood leaves the heart, it is carried throughout the body in blood vessels

Blood Vessels Three main type of blood vessels: Three main type of blood vessels: –Arteries- carry blood away from the heart  Largest artery is the Aorta –Capillaries- connect arterioles with venules, the smallest veins  The exchange of gases takes place in the capillaries –Veins- blood vessels that carry blood back to the heart  Must overcome gravity to get blood back to the heart –One-way valves –Veins are located between skeletal muscles, as muscles contract, they force the blood forward through the veins

Blood Vessels To move the blood through the body, a great deal of force and pressure is required To move the blood through the body, a great deal of force and pressure is required –Blood pressure- the force is at its highest when the ventricles contract, forcing blood out of the heart and into the arteries. Then there is a drop in pressure as the ventricles refill with blood for the next heartbeat  Measured with a device called sphygmomanometer

Blood The average adult contains five liters of blood (four to six quarts) The average adult contains five liters of blood (four to six quarts) Blood is comprised of four components: Blood is comprised of four components: –Plasma –Red blood cells –White blood cells –platelets

Blood A clear, yellowish fluid called plasma makes up the rest of blood. Plasma, 95 percent of which is water, also contains nutrients such as glucose, fats, proteins, and the amino acids needed for protein synthesis, vitamins, and minerals. The level of salt in plasma is about equal to that of sea water. The test tube on the right has been centrifuged to separate plasma and packed cells by density.

Blood Red blood cells Red blood cells –Very small and numerous –Average body has more than 25 trillion red blood cells at any given time –Live for about 3 – 4 months then die –New red cells are created at the rate of 2 million every second –Contain hemoglobin- a protein that attracts oxygen molecules

White blood cells Body’s main defense against germs Body’s main defense against germs Normal count is 5,000 to 10,000 leukocytes per cubic millimeter of blood Normal count is 5,000 to 10,000 leukocytes per cubic millimeter of blood Usually live around three to nine days Usually live around three to nine days Different types of leukocytes Different types of leukocytes

Platelets Smaller than red blood cells Smaller than red blood cells Help blood to clot when there is a cut Help blood to clot when there is a cut Also called thrombocytes Also called thrombocytes Normal count is 250,000 to 400,000 per cubic millimeter of blood Normal count is 250,000 to 400,000 per cubic millimeter of blood Usually live 5-9 days Usually live 5-9 days

Diseases and Abnormal Conditions Anemia- inadequate number of red blood cells, hemoglobin, or both Anemia- inadequate number of red blood cells, hemoglobin, or both Aneurysm – ballooning out of, or saclike formation on, an artery wall Aneurysm – ballooning out of, or saclike formation on, an artery wall

Diseases and Abnormal Conditions Arteriosclerosis- hardening or thickening of the arterial walls Arteriosclerosis- hardening or thickening of the arterial walls Atherosclerosis- fatty plaques (frequently cholesterol) are deposited on the walls of arteries Atherosclerosis- fatty plaques (frequently cholesterol) are deposited on the walls of arteries

Congestive heart failure (CHF)- condition that occurs when the heart muscles do not beat adequately to supply the blood needs of the body Congestive heart failure (CHF)- condition that occurs when the heart muscles do not beat adequately to supply the blood needs of the body Embolus- foreign substance circulating the bloodstream Embolus- foreign substance circulating the bloodstream –Air, blood clot, bacterial clumps, a fat globule Diseases and Abnormal Conditions

Hemophilia- inherited disease, blood is unable to clot Hemophilia- inherited disease, blood is unable to clot Hypertension – high blood pressure Hypertension – high blood pressure Leukemia- malignant disease of the bone marrow, results in a high number of immature white blood cells Leukemia- malignant disease of the bone marrow, results in a high number of immature white blood cells Diseases and Abnormal Conditions

Myocardial infarction- heart attack, occurs when a blockage in the coronary arteries cuts off the supply of blood to the heart, the tissue dies and is known as an infarct Myocardial infarction- heart attack, occurs when a blockage in the coronary arteries cuts off the supply of blood to the heart, the tissue dies and is known as an infarct Phlebitis- inflammation of a vein Phlebitis- inflammation of a vein Varicose veins- dilated, swollen veins that have lost elasticity and cause decreased blood flow Varicose veins- dilated, swollen veins that have lost elasticity and cause decreased blood flow Diseases and Abnormal Conditions

Dr William Harvey

Dr. Dwight Harken

Dr Charles Bailey

Dr. Wilfred ('Bill') Bigelow

Lillehei in He's with Jacquelin Weeks, who underwent the first open heart surgery in 1952, when she was five years old. (Photo courtesy of the University of Minnesota) Dr. Walton Lillehei

Dr. John Gibbon

Dr. Dennis Melrose

Dr. Christiaan Barnard

Dr. Norman Shumway

Dr. Randas Batista

Label heart diagram for numbers 1 –