APHY 102 HEART IVY TECH| 100 QUESTIONS WITH CORRECT ANSWERS| 2023-2024 UPDATE WITH EXPERT FEEDBACK These cells generate an action potential that spreads throughout the myocardium, causing the heart to contract as a single unit. - ANSWERS- autorhythmic cells consists of dense connective tissue in the heart that electrically separates the atria from the ventricles. - ANSWERS- cardiac fibrous skeleton Refers to how electrical impulses propagate freely between cells in every direction due to gap junctions, so that the myocardium functions as a single contractile unit. This property allows rapid, synchronous depolarization of the myocardium. - ANSWERSfunctional syncytium a small body of specialized muscle tissue in the wall of the right atrium of the heart that acts as a pacemaker by producing a contractile signal at regular intervals. It sets the pace because it depolarizes and spreads the impulse throughout the atria fastest. - ANSWERS- Sinoatrial node a part of the electrical conduction system of the heart that coordinates the top of the heart. It electrically connects atrial and ventricular chambers. It also delays impulses by approximately 0.12s. This delay in the cardiac pulse is extremely important: It ensures that the atria have ejected their blood into the ventricles first before the ventricles contract. - ANSWERS- Atrioventricular node as part of the electrical conduction system of the heart, it transmits the electrical impulses from the AV node (located between the atria and the ventricles) to the point of the apex via the bundle branches. - ANSWERS- Atrioventricular bundle provide electrical conduction to the ventricles by spreading action potentials through gap junctions to all the cardiomyocytes in the ventricules. This causes the cardiac muscle of the ventricles to contract at a paced interval. - ANSWERS- Purkinje fibers _______ influence can increase speed of heart rate and strength of contraction - ANSWERS- sympathetic _______ influence can decrease speed of heart rate - ANSWERS- parasympathetic a test that checks for problems with the electrical activity of your heart. It shows the heart's electrical activity as line tracings on paper. The spikes and dips in the tracings are called waves. - ANSWERS- ECG SA node and atrial depolarization - ANSWERS- P wave ventricular depolarization and atrial repolarization - ANSWERS- QRS complex ventricular repolarization - ANSWERS- T wave the noises generated by the beating heart and the resultant flow of blood through it. Specifically, the sounds reflect the turbulence created when the heart valves snap shut. - ANSWERS- heart sounds produced by the closing of the atrioventricular valves - ANSWERS- lub produced by the closing of the semilunar valves - ANSWERS- dub refers to a complete heartbeat from its generation to the beginning of the next beat, and so includes the diastole, the systole, and the intervening pause. - ANSWERS- cardiac cycle 1. Diastole 2. Atrial systole 3. Isovolumetric contraction 4. Ejection 5. Isovolumetric relaxation - ANSWERS- Phases of cardiac cycle when the atrioventricular (AV) valves (the mitral valve and the tricuspid valve) open, and the whole heart is relaxed - ANSWERS- Diastole the atrium contracts, and blood flows from atrium to the ventricle - ANSWERS- Atrial systole when the ventricles begin to contract, the AV and semilunar valves close and the first heart sound is heard, ventricular pressure increases rapidly, and there is no change in volume - ANSWERS- Isovolumetric contraction when the ventricles are contracting and emptying, and the semilunar valves are open - ANSWERS- Ejection pressure decreases rapidly, no blood enters the ventricles, the ventricles stop contracting and begin to relax, and the semilunar valves close due to the pressure of blood in the aorta and the second heart sound is heard - ANSWERS- Isovolumetric relaxation