Regulation of Cardiac Output Flashcards Preview

PHCOL 402 (Mine) > Regulation of Cardiac Output > Flashcards

Flashcards in Regulation of Cardiac Output Deck (13):
1

What happens in diastole?

- Venous return fills the atria
- AV valve opens, then closes

2

What happens in systole?

- Ventricles fill with blood
- Isometric contraction
- Aortic/pulmonary valves open then close

3

What is cardiac output?

Stroke volume x heart rate
- a measurement of how much blood is being pumped out over a period of time

4

What factors determine stroke volume?

preload and afterload

5

What is preload?

- Tension of ventricular muscle BEFORE CONTRACTION
- Determined by LVEDV/LVEDP

6

What is afterload?

The pressure which ventricles are pumping blood against
- determined by total peripheral resistance

7

Where is Na in highest concentration?

Extracellular

8

Where is K in highest concentration?

Intracellular

9

Where is Ca in highest concentration?

Extracellular

10

Which node initiates cardiac rhythm?

SA node

11

What occurs during phase 0 of the action potential?

Calcium enters and depolarizes the cell

12

What occurs during phase 3 of the action potential?

Potassium exits and hyperpolarizes the cell (voltage and ligand gated)

13

What occurs during phase 4 of the action potential?

Sodium and calcium enter the cell and depolarizes the cell
- Occurs naturally