Ch. 6 Structure and Function

Aorta

Largest artery of the body; vessel through which oxygenated blood exits the heart

Aortic valve

Valve between the aorta and the left ventricle

Arteriole

A tiny artery connecting to a capillary

Artery

A thick-walled blood vessel that, in systemic circulation, carries oxygenated blood away from the heart

Atrioventricular bundle

Bundle of fibers in the interventricular septum that transfers charges in the heart’s conduction system; also called the bundle of His

Atrioventricular (AV) node

Specialized part of the interatrial septum that sends a charge to the bundle of His

Atrioventricular valve

One of two valves that control blood flow between the atria and ventricles

Atrium

Either of the two upper chambers of the heart

Bicuspid valve

Atrioventricular valve on the left side of the heart

Blood

Essential fluid made up of plasma and other elements that circulates throughout the body, delivers nutrients to and removes waste from the body’s cells

Blood pressure

Measure of the force of blood surging against the walls of the arteries

Blood vessel

Any of the tubular passageways in the cardiovascular system through which blood travels

Bundle of His

See atrioventricular bundle

Capillary

The smallest blood vessel that forms the exchange point between the arterial and venous vessels

Carbon dioxide

Waste material transported in the venous blood

Cardiac cycle

Repeated contraction and relaxation of the heart as it circulates blood within itself and pumps it out to the rest of the body or the lungs

Cardiovascular

Relating to or affecting the heart and blood vessels

Carotid artery

Artery that transports oxygenated blood to the head and neck

Conduction system

Part of the heart containing specialized tissue that sends electrical charges through heart fibers, causing the heart to contract and relax at regular intervals

Coronary artery

Blood vessel that supplies oxygen-rich blood to the heart

Depolarization

Contracting state of the myocardial tissue in the heart’s conduction system

Diastole

Relaxation phase of a heartbeat

Ductus arteriosus

Structure in the fetal circulatory system through which blood flows to bypass the fetus’s nonfunctioning lungs

Ductus venosus

Structure in the fetal circulatory system through which blood flows to bypass the fetal liver

Endocardium

Membranous lining of the chambers and valves of the heart; the innermost layer of heart tissue

Endothelium

Lining of the arteries that secretes substances into the blood

Epicardium

Outermost layer of heart tissue

Femoral artery

An artery that supplies blood to the thigh

Foramen ovale

Opening in the septum of the fetal heart that closes at birth

Heart

Muscular organ that receives blood from the veins and sends it into the arteries

Inferior vena cava

Large vein that draws blood from the lower part of the body to the right atrium

Left atrium

Upper left heart chamber

Left ventricle

Lower left heart chamber

Lumen

Channel inside an artery through which blood flows

Mitral valve

See bicuspid valve

Myocardium

Muscular layer of heart tissue between the epicardium and the endocardium

Pacemaker

Term for the sinoatrial (SA) node; also, an artificial device that regulates heart rhythm

Pericardium

Protective covering of the heart

Polarization

Resting state of the myocardial tissue in the conduction system of the heart

Popliteal artery

An artery that supplies blood to the cells of the area behind the knee

Pulmonary artery

One of two arteries that carry blood that is low in oxygen from the heart to the lungs

Pulmonary valve

Valve that controls the blood flow between the right ventricle and the pulmonary arteries

Pulmonary vein

One of four veins that bring oxygenated blood from the lungs to the left atrium

Pulse

Rhythmic expansion and contraction of a blood vessel, usually an artery

Repolarization

Recharging state; transition from contraction to resting that occurs in the conduction system of the heart

Right atrium

Upper right chamber of the heart

Right ventricle

Lower right chamber of the heart

Saphenous vein

Any of a group of veins that transport deoxygenated blood from the legs

Semilunar valve

One of the two valves that prevent the backflow of blood flowing out of the heart into the aorta and the pulmonary artery

Septum

Partition between the left and right chambers of the heart

Sinoatrial (SA) node

Region of the right atrium containing specialized tissue that sends electrical impulses to the heart muscle, causing it to contract

Sinus rhythm

Normal heart rhythm

Superior vena cava

Large vein that transports blood collected from the upper part of the body to the heart

Systole

Contraction phase of the heartbeat

Tricuspid valve

Atrioventricular valve on the right side of the heart

Valve

Any of various structures that slow or prevent fluid from flowing backward or forward

Vein

Any of various blood vessels carrying deoxygenated blood toward the heart, except the pulmonary vein

Vena cava

See superior vena cava and inferior vena cava

Ventricle

Either of the two lower chambers of the heart

Venule

A tiny vein connecting to a capillary