Flashcards in Regulation of Cardiac Output Deck (13):
What happens in diastole?
- Venous return fills the atria
- AV valve opens, then closes
What happens in systole?
- Ventricles fill with blood
- Isometric contraction
- Aortic/pulmonary valves open then close
What is cardiac output?
Stroke volume x heart rate
- a measurement of how much blood is being pumped out over a period of time
What factors determine stroke volume?
preload and afterload
What is preload?
- Tension of ventricular muscle BEFORE CONTRACTION
- Determined by LVEDV/LVEDP
What is afterload?
The pressure which ventricles are pumping blood against
- determined by total peripheral resistance
Where is Na in highest concentration?
Where is K in highest concentration?
Where is Ca in highest concentration?
Which node initiates cardiac rhythm?
What occurs during phase 0 of the action potential?
Calcium enters and depolarizes the cell
What occurs during phase 3 of the action potential?
Potassium exits and hyperpolarizes the cell (voltage and ligand gated)