Cardiovascular Disorders Flashcards
What does the bicuspid valve do?
It is the valve between the left atrium and left ventricle. Also called the mitral valve.
What does the tricuspid valve do?
It separates the right atrium and ventricle.
What does the aortic valve do?
It separates the left ventricle and aorta.
What does the pulmonary valve do?
It separates the right ventricle and the pulmonary artery.
Where does the electrical activity of the heart start?
It starts in the sinoatrial node.
Which arrhythmia has an electrical short?
Re-entry
Which arrhythmia has an extended depolarization?
EAD
What is the pathway of calcium in a myocite?
- The current travels through a gap junction from one myocite into another
- The action potential travels through the plasma membranes and through the T tubules
- Ca channels open in the membrane and SR
- Ca induces more Ca release from SR
- Ca binds to troponin, exposing myosin binding sites
- muscle fiber contracts
- Ca releases from troponin and is transported into the SR and ECF
- tropomyosin blocks myosin binding sites, and muscle fiber relaxes.
What are the phases of cardiac myocite action potential? (Also called atrial and ventricular action potential?)
Phase 0: Depolarization Phase 1: Initial Depolarization Phase 2: Plateau Phase 3: Re-polarization Phase 4: Resting potential
Action potentials: what happens in phase 0?
Depolarization. The fast Na channels open at -85mV, and close at 20mV
Action potentials: what happens in phase 1?
Initial repolarization. Na channels close, K leaves.
Action potentials: what happens in phase 2?
The plateau. Fast K channels close, and voltage-gated Ca channels open to let Ca into the cell
Action potentials: what happens in phase 3?
Re-polarization. Ca channels close, slow K channels open.
Action potentials: what happens in phase 4?
Resting potential. Na leaves, K reenters the cell via the Na-K-ATPase pump.
What does the Wigger’s diagram tell us?
It shows what happens in the systole and diastole. The atrium and ventricles oppose each other.