Heart Anatomy and Physiology

Flashcards covering the anatomy, function, and physiology of the heart.

Right Atrium

Receives deoxygenated blood from the body and sends it to the right ventricle.

Right Ventricle

Pumps deoxygenated blood to the lungs through the pulmonary trunk.

Left Atrium

Receives oxygenated blood from the lungs and sends it to the left ventricle.

Left Ventricle

Strongest chamber; pumps oxygen-rich blood to the entire body through the aorta.

Pericardium

Tough protective membrane around the heart.

Visceral Pericardium (Epicardium)

Stuck to the outer surface of the heart.

Parietal Pericardium

Lines the inside of the pericardial sac.

Pericardial Cavity

Space between the visceral and parietal pericardium, filled with pericardial fluid for lubrication.

Coronary Sulcus

Deep groove separating the atria and ventricles; contains coronary blood vessels.

Anterior Interventricular Sulcus

Front depression marking division between the left and right ventricles.

Posterior Interventricular Sulcus

Back depression marking division between the left and right ventricles; houses major blood vessels.

Epicardium

Outer layer of the heart, also the visceral pericardium.

Myocardium

Middle layer of the heart; cardiac muscle that contracts to pump blood.

Endocardium

Inner lining of the chambers and valves of the heart.

Septum

Wall separating chambers of the heart.

Tricuspid Valve

Valve between right atrium and right ventricle.

Pulmonary Semilunar Valve

Valve between right ventricle and pulmonary trunk.

Bicuspid (Mitral) Valve

Valve between left atrium and left ventricle.

Aortic Semilunar Valve

Valve between left ventricle and aorta.

Chordae tendinae and papillary muscles

Hold the AV valves in place during contraction to prevent backflow.

Superior Vena Cava

Vessel that empties into the right atrium bringing deoxygenated blood from the upper body.

Inferior Vena Cava

Vessel that empties into the right atrium bringing deoxygenated blood from the lower body.

Coronary Sinus

Vessel that empties into the right atrium bringing deoxygenated blood from the heart tissue itself.

Left and Right Pulmonary Veins

Vessels that empty into the left atrium bringing oxygenated blood from the lungs.

Coronary Arteries

Supply oxygen-rich blood to heart muscle (myocardium).

Right Coronary Artery

Supplies right atrium, both ventricles, and pacemaker nodes.

Left Coronary Artery

Supplies left atrium/ventricle, septum.

Coronary Veins

Drain blood from the heart muscle.

Conduction System

Controls the heart's electrical activity.

Sinoatrial (SA) Node

Pacemaker in right atrium.

Atrioventricular (AV) Node

Delays impulse to let atria empty.

Purkinje Fibers

Cause ventricles to contract.

EKG (ECG)

Records electrical signals from the heart.

P Wave

Atrial depolarization (atria contract).

QRS Complex

Ventricular depolarization (ventricles contract).

T Wave

Ventricular repolarization (reset).

Rapid Depolarization

Sodium (Na⁺) enters fast → voltage spikes.

Plateau Phase

Calcium (Ca²⁺) enters slowly → keeps voltage steady → longer contraction.

Repolarization

Potassium (K⁺) exits → resets voltage.

Atrial Systole

Atria contract → push blood to ventricles.

Ventricular Systole

Ventricles contract → push blood to lungs/body.

Ventricular Diastole

Ventricles relax → refill with blood.

S1 ('lubb')

AV valves close (ventricles contract).

S2 ('dubb')

Semilunar valves close (ventricles fill).

EDV (End-Diastolic Volume)

Blood in ventricle after filling (65–240 mL).

ESV (End-Systolic Volume)

Blood left after contraction (16–143 mL).

SV (Stroke Volume)

Blood pumped per beat → SV = EDV - ESV (55–100 mL).

CO (Cardiac Output)

Blood pumped per minute → CO = HR × SV (normal ~4–5 L/min).

Preload

Stretch of ventricles during filling → more stretch = stronger contraction = more SV.

Afterload

Resistance the heart must overcome to push blood out. Higher afterload = lower SV.

Frank-Starling Principle

More in = more out → more blood in the ventricle = stronger pump out.