Glossary: The Cardiovascular System

Transcription

1 This glossary includes terms that have been introduced in Lesson 14. Student Resource Glossary: The Cardiovascular System Anatomy Terms aorta Large artery that transports blood from the left ventricle to the whole body. apex The tip, or bottom, of the heart that points slightly to the left inside the chest. arteries Blood vessels that carry blood away from the heart. atrium One of the upper chambers of the heart. bicuspid valve A heart valve between the left atrium and left ventricle that has two flaps (leaflets). blood A tissue of the cardiovascular system made of red and white blood cells, platelets, and plasma, and that transports all the vital substances in the body. capillaries Tiny blood vessels with walls so thin that they allow substances such as nutrients, oxygen, and hormones to cross. capillary bed The network of capillaries that connects an artery to a vein.

2 coronary arteries Arteries that supply blood to the tissues of the heart. erythrocytes Another term for red blood cells. granulocytes White blood cells, found in blood, that die after they have phagocytosed an invading microbe or substance. macrophage A white blood cell that can go through phagocytosis over and over, and can live for many decades. pericardium A sac that encloses the heart and anchors it to the sternum. plasma The fluid portion of the blood that transports nutrients, hormones, waste products, and other important substances. platelets Fragments of cells in the blood that contain proteins that initiate the process of blood clotting. pulmonary artery Large artery that transports deoxygenated blood from the right ventricle to the lungs. pulmonary vein Veins that transport oxygenated blood from the lungs to the left atrium of the heart. red blood cells Donut-shaped blood cells that contain hemoglobin and transport oxygen. septum The wall of muscle that divides the two sides of the heart. sinoatrial node A cluster of special cells that generates the action potentials that stimulate the heart muscle to contract.

3 tricuspid valve A heart valve between the right atrium and ventricle that has three flaps. veins Blood vessels that transport blood from the tissues of the body back to the heart. venae cavae Large veins that return blood to the heart, delivering it to the right atrium. ventricle One of the two lower chambers of the heart. These are muscular structures that contract to propel blood into the large arteries. white blood cells Cells that protect against invaders and dangerous substances. Some are in the blood and can travel throughout the body to go where they are needed. Other white blood cells live in the body tissues outside of the blood. Physiology Terms antibodies Special proteins of the immune system that can neutralize toxic substances or identify infectious invaders like viruses and bacteria and destroy them. antigens Proteins that can cause an immune response if a person s body identifies them as foreign. baroreceptors Sensory receptors in the walls of blood vessels that detect the pressure of blood against the vessel wall. capillary exchange The movement of nutrients, oxygen, hormones, and other important substances across capillary walls.

4 hemoglobin The protein making up most of a red blood cell. It contains iron ions that bind oxygen and carbon dioxide. phagocytosis The process of engulfing and destroying microbial invaders, used by white blood cells. pulmonary circuit The path that brings deoxygenated blood from the right side of the heart to the lungs and returns the oxygenated blood to the left side the heart. systemic circuit The path that brings that oxygenated blood to all of a person s cells and then returns it to the right side of the heart to get sent back to the lungs. Medical Terms ABO blood groups The blood groups determined by the presence or absence of the A or B antigens on the surface of red blood cells. anemia A condition that results from having too few red blood cells or too little hemoglobin. arrhythmia A disruption of the heart s usually coordinated heartbeat. It may affect the atria, the ventricle, or the heart as a whole. atherosclerosis A specific type of hardening of the arteries, when fatty deposits, called plaque, build up on the inside of the arteries. blood pressure The measurement of the pressure blood exerts on artery walls when ventricles contract and when they are at rest.

5 diastolic blood pressure The pressure of blood against the artery walls when the ventricles are relaxed. electrocardiogram (ECG) A recording of the electrical signals that move through the heart when it contracts. Health care professionals can look at the signal for information about how well different parts of the heart are working. heart attack When blood flow to part of the heart muscle is blocked. If blood flow to the muscle is cut off for too long, muscle cells will begin to die and the heart will become damaged. plaque A substance containing fats, cholesterol, waste products, and other substances that can build up on the walls of blood vessels, decreasing the space available for blood to flow through. pulmonary circuit The path that brings deoxygenated blood from the right side of the heart to the lungs and returns oxygenated blood to the left side the heart Rh factor An antigen that determines whether a person s blood type is positive (contains the antigen) or negative (doesn t contain the antigen) for the Rh protein on the surface of his or her red blood cells. stroke A condition caused when blood flow is blocked in an artery that supplies part of the brain, or when a blood vessel in the brain ruptures. systolic blood pressure The pressure of blood against the artery walls when the ventricles contract.