Cardiovascular System Quiz (BMS Learning Outcomes)

Heart Structure and Function

• The heart is a fist-sized, muscular organ in the thoracic cavity, positioned between the lungs.
• It has four chambers: two atria (right and left) and two ventricles (right and left).
• The right side pumps deoxygenated blood to the lungs, the left side pumps oxygenated blood to the body.
• The heart has three layers: epicardium (outer), myocardium (thick muscle layer), and endocardium (inner lining).
• Valves (tricuspid, mitral, pulmonary semilunar, aortic semilunar) ensure unidirectional blood flow.

Heart Blood Flow

• Deoxygenated blood returns to the right atrium via the vena cavae.
• It flows through the tricuspid valve to the right ventricle.
• The right ventricle pumps blood through the pulmonary semilunar valve to the lungs.
• Oxygenated blood returns to the left atrium via the pulmonary veins.
• It passes through the mitral valve to the left ventricle.
• The left ventricle pumps blood through the aortic semilunar valve to the aorta.

Cardiac Conduction System

• Specialized cardiac tissue controls the heartbeat.
• The sinoatrial (SA) node is the primary pacemaker, initiating electrical impulses in the right atrium.
• The atrioventricular (AV) node delays impulses, allowing atrial contraction before ventricular contraction.
• The bundle of His conducts impulses from the AV node to the ventricles.
• Purkinje fibers distribute impulses throughout the ventricles, triggering contraction.

Coronary Circulation

• The heart receives oxygenated blood via the coronary arteries (right and left), branching off the aorta.
• These arteries supply the myocardium.
• Deoxygenated blood returns to the right atrium through cardiac veins that drain into the coronary sinus.

Circulatory System Vessels

• Arteries carry oxygenated blood away from the heart (except pulmonary arteries).
• Veins carry deoxygenated blood to the heart (except pulmonary veins).
• Capillaries facilitate gas and nutrient exchange.
• Major vessels include the aorta, pulmonary arteries and veins, and vena cavae.