Cardiovascular Unit Flashcards

The heart acts as a transport system pump that circulates blood through pulmonary and systemic circuits.

Receives deoxygenated blood from the body and pumps it to the lungs via the pulmonary circuit.

Receives oxygenated blood from the lungs and pumps it to the body via the systemic circuit.

The left ventricle has thicker walls to generate higher pressure for systemic circulation; the right ventricle is thinner for low-pressure pulmonary circulation.

Short, low-pressure system that carries blood from the right ventricle to the lungs and back to the left atrium.

Long, high-pressure system that carries oxygenated blood from the left ventricle to the body and returns deoxygenated blood to the right atrium.

SVC/IVC/Coronary sinus → Right atrium → Tricuspid valve → Right ventricle → Pulmonary semilunar valve → Pulmonary trunk → Pulmonary arteries → Lungs → Pulmonary veins → Left atrium → Mitral valve → Left ventricle → Aortic semilunar valve → Aorta → Body.

Tricuspid and mitral valves prevent backflow into atria when ventricles contract.

Pulmonary and aortic semilunar valves prevent backflow from major arteries into ventricles.

Lub: AV valves closing at start of systole; Dub: SL valves closing at start of diastole.

An abnormal heart sound caused by obstructed or incompetent valves.

Ridges in atrial walls that help atria contract efficiently.

Muscles in ventricles that anchor chordae tendineae to prevent valve flaps from inverting.

Fibrous cords that prevent AV valve cusps from everting into atria during ventricular contraction.

Fetal opening between atria that allows blood to bypass the lungs before birth.

Double-walled sac surrounding the heart that protects and anchors it.

Fibrous pericardium (outer) and serous pericardium (parietal and visceral layers).

Epicardium (outer), myocardium (muscle), endocardium (inner lining).

Inflammation of the pericardium causing friction rub.

Compression of the heart due to excess fluid in the pericardial space.

Chest pain caused by reduced blood flow (ischemia) to the myocardium.

Prolonged coronary blockage causing cardiac cell death (heart attack).

Reduced blood flow to tissue, causing oxygen deprivation.

Functional blood supply to the heart muscle itself.

Left coronary artery (anterior interventricular & circumflex branches) and right coronary artery (right marginal & posterior interventricular branches).

Cardiac veins empty into the coronary sinus, which drains into the right atrium.

Network of autorhythmic cells that initiate and distribute impulses for coordinated heart contraction.

Pacemaker of the heart; generates impulses at ~75 beats per minute.

Delays impulses (~0.1 sec) to allow atrial contraction before ventricular contraction.

Only electrical connection between atria and ventricles.

Spread impulses through ventricular walls for coordinated contraction.

Provides parasympathetic input to slow heart rate.

Atrial depolarization (SA node activity).

Ventricular depolarization and atrial repolarization.

Ventricular repolarization.

Cardiac ischemia.

Period of heart contraction.

Period of heart relaxation.

Amount of blood pumped by each ventricle per minute; CO = HR × SV.

Volume of blood pumped by one ventricle per beat (~70 mL).

The more cardiac muscle cells are stretched, the stronger they contract.

Increases heart rate and shortens intervals; improves efficiency.

Specialized junctions with desmosomes and gap junctions that allow cardiac cells to contract as a coordinated unit.

Short, branched, single-nucleated cells with many mitochondria; contracts as a functional syncytium; depends on aerobic respiration.