A&P 2: CVS Heart 2

Concepts to practice

Cardiac output

Volume of blood ejected from the left or right ventricle into aorta or pulmonary trunk each minute

Formula to determine Cardiac output

CO = SV X HR

Cardiac output = stroke volume x heart rate

What are anastomoses and why are they important

Anastomoses are connections where two or more arteries supply the same region. They provide collateral circulation (alternate routes) so the heart muscle can receive enough oxygen even if the main coronary artery is partially obstructed

What are the 4 primary roles of the fibrous skeleton of the heart?

1. Forms the foundation for which heart valve attach

2. Provides insertion points for cardiac muscle bundles

3. Prevents overstretching of valves

4. Acts as an electrical insulator to prevent the direct spread of action potentials from atria to ventricles

What occurs during the "isovolumetric contraction" phase of the cardiac cycle?

During isovolumetric contraction, ventricular depolarization causes the ventricles to contract, pushing the AV valves closed.
For 0.05 seconds, all four valves (AV and SL) are closed, and the volume of blood within the ventricles remains the same as pressure rises.

Stroke volume

Amount of blood ejected from ventricles per beat = 70 mL