Structure & Function of the Cardiovascular System (Part II) questions with complete solutions

What is the resting potential in a ventricle? correct answer: -90 mV What is the resting potential in the SA node? correct answer: ~60 mV What is the resting potential in the Atrium? correct answer: -90 mV What phase is depolarization of the cardiac action potential and is when there is rapid Na+ entry (fast channels) correct answer: Phase 0 What phase is early repolarization and is where Ca+ SLOWLY enters, Na+ channels close and K+ channels remain open correct answer: Phase 1 What phase is the plateau, continuation of repolarization and continued slow entry of Ca+ balanced by K+ out correct answer: Phase 2 What phase is rapid repolarization, Ca+ channels close, and K+ moves out of the cell correct answer: Phase 3 What phase is when the action potential returns to rest, Na+/K+ pump correct answer: Phase 4 What does not have a slow phase 0 and no plateau? correct answer: SA and AV nodes Which type of muscle tissue has long and cylindrical fibers? correct answer: skeletal muscle Which type of muscle tissue has intercalated discs? correct answer: cardiac muscle Which type of muscle tissue is thick in the middle and tapered at each end? correct answer: smooth muscle What allows myocardial cells to transmit action potentials faster? correct answer: intercalated discs Because myocardial cells have large amounts of mitochondria, what does it allow it to do? correct answer: synthesize more ATP Myocardial cells have more access to ions in the interstitium because of an abundance of