Chapter 19 The Circulatory System: Heart Anatomy & Physiology

Vocabulary flashcards covering key heart anatomy, valves, coronary vessels, and the cardiac conduction system.

Cardiology

The study of the heart and its disorders.

Heart

A pump that keeps blood flowing through the blood vessels.

Arteries

Carry blood away from the heart.

Veins

Carry blood toward the heart.

Capillaries

Microscopic vessels connecting the smallest arteries to the smallest veins.

Pulmonary circuit

Circuit that carries blood to the lungs for gas exchange and back to the heart.

Systemic circuit

Circuit that carries oxygenated blood to the tissues of the body and returns it to the heart.

Mediastinum

Space in the chest between the lungs where the heart sits.

Base of the heart

The wide, superior portion of the heart.

Apex

The tapered inferior end of the heart that tilts to the left.

Pericardium

A double-walled sac enclosing the heart; provides frictionless beating and room to expand, yet resists excessive expansion.

Fibrous pericardium

Outer layer of the pericardium.

Serous pericardium

Inner layer of the pericardium; has parietal and visceral layers.

Parietal pericardium

Outer serous layer lining the pericardial cavity.

Visceral pericardium (epicardium)

Inner serous layer that covers the surface of the heart.

Pericardial cavity

Space between parietal and visceral layers filled with fluid.

Epicardium

Visceral layer of the serous pericardium; contains coronary vessels and fat.

Myocardium

Thick middle layer of cardiac muscle; thickness reflects workload.

Endocardium

Smooth inner lining of the heart; covers valve surfaces.

Interatrial septum

Wall separating the right and left atria.

Interventricular septum

Wall separating the right and left ventricles.

Auricle

Overlapping earlike flap that increases chamber volume.

Pectinate muscles

Internal ridges of myocardium in the atria.

Trabeculae carneae

Internal muscular ridges in the ventricles that aid refill.

Right AV valve (tricuspid)

Valve between the right atrium and right ventricle; usually has three cusps.

Left AV valve (mitral)

Valve between the left atrium and left ventricle; usually has two cusps.

Pulmonary valve

Valve between the right ventricle and the pulmonary trunk.

Aortic valve

Valve between the left ventricle and the aorta.

Tendinous cords

Cordae tendineae; strings that attach valve cusps to papillary muscles.

Papillary muscles

Muscles that anchor the chordae tendineae and prevent valve inversion.

AV valves

Valves between atria and ventricles (tricuspid and mitral) that prevent backflow into atria.

Semilunar valves

Valves between the ventricles and the great arteries (pulmonary and aortic).

Left coronary artery (LCA) and branches

Supplies the left side of the heart; branches include circumflex and anterior interventricular.

Right coronary artery (RCA)

Supplies the right side of the heart; gives rise to the right marginal and other branches.

Coronary sinus

Large venous channel that drains most of the heart into the right atrium.

Great cardiac vein

Vein that accompanies the left coronary artery and drains into the coronary sinus.

Fossa ovalis

Remnant of the fetal foramen ovale in the interatrial septum.

Sinoatrial (SA) node

Natural pacemaker; initiates the heartbeat.

Atrioventricular (AV) node

Delays impulse between atria and ventricles.

AV bundle (bundle of His)

Conduits impulse from AV node toward the ventricles.

Subendocardial branches

Branches distributing excitation through the ventricular myocardium.

Cardiac conduction system

Electrical system that coordinates heartbeat; includes SA node, AV node, AV bundle, and subendocardial branches.