Cardiovascular System — Study Pack (2025-26) Flashcards

Front

Heart

Back

A muscular pump located in the mediastinum that circulates blood through the pulmonary and systemic circuits. It maintains pressure and flow to deliver oxygen and remove waste from tissues.

Front

Mediastinum

Back

The central compartment of the thoracic cavity between the lungs that houses the heart, great vessels, trachea, and esophagus. It provides anatomical protection and positional stability for the heart.

Front

Myocardium

Back

The thick, muscular middle layer of the heart wall responsible for generating contractile force. It contains cardiac muscle cells specialized for rhythmic contraction.

Front

Endocardium

Back

The inner endothelial lining of the heart chambers and valves. It provides a smooth surface for blood flow and interfaces with the cardiac conduction system.

Front

Epicardium

Back

The outer layer of the heart wall that forms part of the pericardium. It provides protective tissue and contains coronary vessels that supply the myocardium.

Front

Atria

Back

The two upper chambers of the heart that receive blood: the right atrium receives systemic venous blood, and the left atrium receives oxygenated pulmonary venous blood. They contribute to ventricular filling.

Front

Ventricles

Back

The two lower, muscular chambers that eject blood: the right ventricle pumps to the lungs, and the left ventricle pumps to the systemic circulation. Ventricular contraction generates arterial pressure.

Front

AV valves

Back

Atrioventricular valves (tricuspid and mitral) separate atria from ventricles and prevent backflow during ventricular contraction. They are anchored by papillary muscles and chordae tendineae.

Front

Semilunar valves

Back

The aortic and pulmonary valves located at the ventricular outflow tracts. They open during ventricular ejection and close to prevent blood returning to the ventricles.

Front

Coronary arteries

Back

Arteries that supply oxygen-rich blood to the myocardium. The right coronary artery typically supplies the right heart and portions of the left, while the left coronary artery and its branches supply much of the left heart.

Front

SA node

Back

The sinoatrial node is the heart's primary pacemaker located in the right atrium. It initiates electrical impulses that set the heart rate and rhythm.

Front

AV node

Back

The atrioventricular node delays conduction between atria and ventricles, allowing atrial contraction to complete ventricular filling. It also serves as a secondary pacemaker if the SA node fails.

Front

Purkinje fibres

Back

Fast-conducting fibers in the ventricular endocardium that distribute impulses rapidly across the ventricles. They ensure coordinated and synchronized ventricular contraction.

Front

P wave

Back

The ECG waveform representing atrial depolarization, typically initiated by the SA node. It precedes atrial contraction and ventricular activation.

Front

QRS complex

Back

The ECG complex representing ventricular depolarization and the main electrical event associated with ventricular contraction. It is normally brief and high amplitude.

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T wave

Back

The ECG waveform reflecting ventricular repolarization and the recovery phase of the ventricular myocardium. Abnormalities can indicate ischemia or electrolyte disturbances.

Front

Cardiac cycle

Back

The sequence of mechanical and electrical events from the end of one heartbeat to the next, including diastole (filling) and systole (ejection). It coordinates valve movements and blood flow.

Front

Stroke volume

Back

The volume of blood ejected by each ventricle with each contraction. It depends on preload, afterload, and contractility.

Front

Cardiac output

Back

The volume of blood the heart pumps per minute, calculated as heart rate multiplied by stroke volume. Typical resting cardiac output is about 5 litres per minute in an adult.

Front

Blood pressure

Back

The hydrostatic pressure exerted by blood on vessel walls, usually expressed as systolic over diastolic in mmHg. It is determined by cardiac output and total peripheral resistance.