medphysobj Cardiovascular the APS（medphysobj心血管APS）.pdf

The American Physiological Society Medical Curriculum Objectives Project Complete curriculum objectives available at: /medphysobj Cardiovascular (revised 2011) Unique Characteristics of Cardiac Muscle CV 1. Contrast the duration of the action potential and the refractory period in a cardiac muscle, a skeletal muscle, and a nerve. Sketch the temporal relationship between an action potential in a cardiac muscle cell and the resulting contraction (twitch) of that cell. On the basis of that graph, explain why cardiac muscle cannot remain in a state of sustained (tetanic) contraction. CV 2. State the steps in excitation-contraction coupling in cardiac muscle. Outline the sequence of events that occurs between the initiation of an action potential in a cardiac muscle cell and the resulting contraction and then relaxation of that cell. Provide specific details about the special role of Ca2+ in the control of contraction and relaxation of cardiac muscle. CV 3. Compare cardiac and skeletal muscle with respect to: cell size, electrical connections between cells, and arrangement of myofilaments. Based on ion permeability and electrical resistance describe role of gap junctions in creating a functional syncytium. CV 4. Identify the role of extracellular calcium in cardiac muscle contraction. Identify other sources of calcium that mediate excitation-contraction coupling, and describe how intracellular calcium concentration modulates the strength of cardiac muscle contraction. CV 5. Describe the role of Starling’s Law of the Heart in keeping the output of the left and right ventricles equal. CV 6. Describe the difference in the way changes in preload and changes in contractility influence ventricular