PHYS Cardiovascular System Overview & Haemodynamics Flashcards
Systemic circulation/’left heart’
Process of moving blood from left ventricle to all organs (including heart & lungs) and then back to the right atrium.
Pulmonary circulation/’right heart’
Process of moving blood from right ventricle to lungs and then back to the left atrium.
State pressure of systemic circulation.
High pressure.
State pressure of pulmonary circulation.
Low pressure.
Pathway of blood from left atrium
Left atrium (mitral valve) -> left ventricle (aortic valve) -> aorta (arteries) -> cerebral/coronary/renal/GI/skeletal muscle/skin (veins) (vena cava) -> right atrium (tricuspid valve) -> right ventricle (pulmonic valve) -> pulmonary artery -> lungs -> pulmonary vein…
Symptoms of Right Heart Failure
Symptoms include swelling in feet, hands and abdominal cavity.
Compare & contrast laminar and turbulent blood flow.
Laminar - smooth, no swirling (silent),
Turbulent - swirling, eddies (noise).
Effect of vessel length on resistance to blood flow
Increase in length corresponds to increased resistance.
Effect of vessel radius/diameter on resistance to blood flow
Increase in radius corresponds to decreased resistance.
Effect of blood/viscosity on resistance to blood flow
Increase in RBC concentration corresponds to increased viscosity.
What contributes to blood viscosity?
Haematocrit (% of blood occupied by RBCs) -> polycythemia -> increases blood viscosity -> increases risk of heart attack, stroke, PE…
What factor has the greatest impact on resistance to blood flow?
Diameter of blood vessel.
Compare resistance of the pulmonary & systemic circulation
Pulmonary resistance < Systemic resistance.
What circuit runs in parallel?
Systemic circuit.
Formula of vessel resistance
Pressure gradient/blood flow = Vessel resistance.
