Structure and Function of the Cardiovascular System
Learning Objectives
- Be able to distinguish the four chambers and the left and the right sides of the heart. Be able to identify the internal features of the heart: the inter ventricular septum, the valves, the chordae tendineae, and the papillary muscles.
- Be able to identify the large arteries and veins of the chest, neck, and abdomen. Know the pattern of blood flow–that arteries carry blood away from the heart and veins return blood to the heart.
- Know that the heart sounds are caused by the closing of the valves. Be able to relate the heart sounds to the two major phases of the cardiac cycle: know that the first heart sound (S1) occurs at the beginning of systole and that the second heart sound (S2) occurs at the beginning of diastole. Know the positions on the chest that are best for listening to specific valves. Know that heart murmurs are caused by turbulent blood flow. Be able to identify whether a particular type of valve disorder causes a murmur that is systolic or diastolic. Understand the anatomy underlying transcatheter aortic valve replacement, a procedure that is used to treat aortic stenosis.
- Be able to explain how blood pressure is measured with a sphygmomanometer. Explain the basis for the sounds (Korotkoff sounds) heard during blood pressure measurement. Be able to define systolic pressure and diastolic pressure. Be able to calculate pulse pressure and calculate estimated mean arterial pressure.
- Know that blood vessels consist of three layers: the tunica intima, the tunica media, and the tunica adventitia. The tunica media is the layer that differs the most between different types of vessels. Be able to identify the following types of vessels: elastic artery, muscular artery, arteriole, vein, and capillary.
- Know that atherosclerosis is a disorder of the arteries that develops in the tunica intima. Atherosclerotic plaque can cause reduced blood flow, or if an atherosclerotic plaque ruptures, a clot can form that may block a blood vessel to cause a myocardial infarction of a stroke. Know that increased LDL cholesterol increases the risk for atherosclerotic cardiovascular disease.
- Know that cholesterol is transported through the circulation in lipoproteins. Know the function of the different lipoproteins: chylomicrons, VLDL LDL, and HDL. The liver is the key organ determining cholesterol homeostasis. Know that hepatocytes (liver cells) synthesize cholesterol , which is delivered to other cells in the body via LDL. LDL and other lipoproteins are taken up into cells via the process of receptor-mediated endocytosis. Familial hypercholesterolemia is a genetic disease in which cholesterol homeostasis is dysfunctional, and is usually caused by mutations in the LDL receptor. Know the mechanism of action for drugs that are used to treat dyslipidemia: statins, ezetimibe, and PCSK9 inhibitors.