Cardiovascular Terms

Question 1

Cardiovascular Disease

Answer 1

• leading cause of mortality and morbidity in the Western World
• coronary artery disease is the most prevalent form
• valvular heart disease is also quite common
• heart valves can become diseased, and they are essential for directing blood flow

Question 2

Valve Diseases

Answer 2

• endocarditis (infection of the heart valve), causes rapid destruction of heart valves and heart failure
• most common is calcific aortic stenosis, can take decades to develop
• aortic valve regurgitation: less common, causes left ventricle overload
• mitral stenosis, caused by chronic rheumatic heart disease, scars and stiffens mitral leaflets
• congenital anomalies, rare

Question 3

Cardiac Electrical cycle

Answer 3

• beings with the sinoatrial node (SA), or the heart’s natural pacemaker
• spreads through muscle of left/right atrial walls and causes contraction, arriving at the atrioventricular (AV) node
• after a short delay, impulse is passed to the bundle of His, then into the left/right bundle branches
• spreads to right and left ventricular myocardium and causes a wave of contraction

Question 4

Cardiac arrhythmias

Answer 4

• disturbances in impulse initiation or conduction
• how to treat: antiarrhythmic drugs, electrical therapy, or surgical therapy to remove tissue/interrupt abnormal pathway

Question 5

Human circulation anatomy

Answer 5

• two parallel circuits
• systemic circulation: comprised of the aortic valve, aorta, branching into smaller arteries, arterioles, capillaries, then coalesce into small/progressively larger veins returning blood to the heart through the inferior and superior vena cava
• pulmonary circulation: comprised of the pulmonary valve and artery, branching into smaller arteries, etc. in the lungs, then veins return blood to the heart via the pulmonary vein

Question 6

Vessel Wall Layers

Answer 6

• Intima: endothelial cells, subendothelial connective tissue, internal elastic lamina
• Media: smooth muscle cells and external elastic laminia
• Adventitia: collagenous connective tissue
• Vasa vasorum: small arterioles in the adventitia of large vessels that send capillaries into the media layer (STUDY DIAGRAM)

Question 7

Heart’s vessel structure

Answer 7

• Endocardium (~ intima)
• myocardium (~ media)
• epicardium (~ adventitia)

Question 8

Types of Vascular Disease

Answer 8

1) blockage of small-to-medium arteries causing ischemia (atherosclerosis, intimal hyperplasia, or thrombosis, with coronary artery blockages causing infarctions and cerebral artery blockages causing strokes)
2) stenosis of large arteries, weakening wall and causing aneurysms (abnormal dilation of blood vessel), promotes thrombosis
3) dissection is a large arterial disease, blood enters wall of the artery, forms a hematoma, and separates its layers

Question 9

Atherosclerosis

Answer 9

• disease in which the inside of a blood vessel narrows/becomes occluded due to plaque formation
• plaque forms via smooth muscle cell (SMC) proliferation, collagen production, and accumulation of lipids
• occurs in arteries or veins

Question 10

Intimal Hyperplasia

Answer 10

• occurs after vessel injury, in which endothelial cells are lost from the luminal wall
• SMCs attempt to reconstitute by migrating from the media to intima, multiplying as intimal cells, and depositing ECM causing thickening
• can cause stenosis/occlusion of small and medium vessels