Heart Anatomy & Physiology – Vocabulary Review

A comprehensive set of vocabulary flashcards covering major anatomical structures, physiological concepts, and conduction terminology of the heart and circulatory system.

Anatomy

Branch of science that studies body structure; e.g., describing the heart’s size, location, and layers.

Physiology

Branch of science that studies body function; e.g., how the heart pumps blood.

Heart

Muscular organ about the size of a closed fist that pumps blood to meet the body’s metabolic needs.

Epicardium

Outermost heart layer that contains the coronary arteries; also called the visceral pericardium.

Myocardium

Thick middle muscular layer of the heart responsible for contraction; damaged during myocardial infarction.

Endocardium

Thin innermost layer that lines chambers and forms heart valves; houses the conduction system.

Pericardium

Double-walled sac surrounding the heart, providing support and protection.

Pericardial Fluid

Lubricating fluid between pericardial layers that reduces friction during each heartbeat.

Septum

Partition that divides the heart into right/left and upper/lower sections.

Atrium (Atria)

Upper heart chambers that receive blood returning to the heart.

Ventricle

Lower heart chambers that pump blood out of the heart; left ventricle has the thickest muscle.

Atrioventricular (AV) Valve

Valve located between an atrium and a ventricle; allows one-way blood flow.

Tricuspid Valve

Right-sided AV valve with three cusps between right atrium and right ventricle.

Bicuspid (Mitral) Valve

Left-sided AV valve with two cusps between left atrium and left ventricle.

Semilunar Valve

Half-moon–shaped valve at ventricular outflow tracts (pulmonary and aortic valves).

Pulmonary Valve

Semilunar valve at exit of right ventricle that directs blood toward the lungs.

Aortic Valve

Semilunar valve at exit of left ventricle that directs blood into the aorta and body.

Vein

Blood vessel that carries deoxygenated blood toward the heart (except pulmonary vein).

Artery

Blood vessel that carries oxygenated blood away from the heart (except pulmonary artery).

Capillary

Microscopic vessel connecting arterioles to venules where gas and nutrient exchange occurs.

Superior Vena Cava

Large vein returning deoxygenated blood from upper body to right atrium.

Inferior Vena Cava

Large vein returning deoxygenated blood from lower body to right atrium.

Aorta

Largest artery; carries oxygenated blood from left ventricle to systemic circulation.

Pulmonary Artery

Only artery carrying deoxygenated blood; transports blood from right ventricle to lungs.

Pulmonary Vein

Only vein carrying oxygenated blood; transports blood from lungs to left atrium.

Cardiac Cycle

Sequence of one heart contraction (systole) and one relaxation (diastole); equals one heartbeat.

Diastole

Relaxation phase of the cardiac cycle when ventricles fill with blood.

Systole

Contraction phase of the cardiac cycle when ventricles eject blood.

Coronary Arteries

Vessels that supply blood to the heart muscle itself; originate at the aorta’s base.

Left Anterior Descending (LAD) Artery

Coronary branch supplying anterior wall of left ventricle.

Circumflex Artery

Coronary branch supplying lateral wall of left ventricle; gives PDA in 30% of people.

Right Coronary Artery (RCA)

Coronary vessel feeding right ventricle and inferior left ventricle; gives PDA in 70% of people.

Myocardial Infarction (MI)

Death of myocardial tissue due to interrupted blood supply; commonly called a heart attack.

Cardiac Conduction System

Specialized pathway that generates and transmits electrical impulses to coordinate heartbeats.

Sinoatrial (SA) Node

Heart’s natural pacemaker located in upper right atrium; fires 60–100 bpm.

Atrioventricular (AV) Node

Backup pacemaker in lower right atrium; fires 40–60 bpm and delays impulse transmission.

Bundle of His

Conductive fibers in septum; part of backup pacemaker system firing 40–60 bpm.

Bundle Branches

Right and left divisions of the Bundle of His that conduct impulses through the septum.

Purkinje Fibers

Network stimulating ventricular myocardium; intrinsic rate 20–40 bpm.

Automaticity

Ability of cardiac cells to generate an impulse without external stimulus.

Conductivity

Ability of cardiac cells to pass an electrical impulse to neighboring cells.

Excitability

Ability of cardiac cells to respond to an electrical stimulus by depolarizing.

Contractility

Mechanical ability of cardiac muscle cells to shorten and generate force.

Electrolyte

Ion (e.g., Na⁺, K⁺, Cl⁻) that carries electrical charge crucial for cardiac conduction.