Introduction to CVS Flashcards
Why is the CVS important (what are it’s functions)
Reproduction, lymphatic system, hormones/immune mediators, nutrients, pumping blood, thermoregulation
Why is passive diffusion not suitable for transport throughout the whole body
Time needed to diffuse a given distance is proportional to the square of the distance, so becomes more time consuming over a bigger distance
How is blood flow created
Output of blood at high pressure creates a pressure difference with distant blood vessels
Pressure difference drives blood flow.
Equation for cardiac output
CO = HR x SV
What is Starling’s Law
If the heart is stretched (more blood in the heart), it will pump harder
During exercise, muscular contraction pushes more blood into the heart so there is greater contraction
Blood flow is proportional and inversely proportional to
Proportional to pressure across blood vessel
Inversely proportional to resistance of blood vessel
Describe and state equation for blood flow and resistance
Blood flow = (Pressure artery - Pressure vein) / Resistance
What do arterioles and arteries do
Arterioles are resstance vessels, which control arterial BP and regulate local blood flow.
Arteries are elastic vessels, which accommodate stroke volume, convert ejection into continuous flow.
What do venules and veins and capillaries do
Venules/veins -> Capacitance vessels, control filling pressure of the heart and provide a reservoir of blood
Capillaries -> Exchange vessels, responsible for nutrient delivery to cell tissue water and lymph formation removal of metabolic waste.
Where is the majority of blood
Systemic veins and venules serve as a reservoir holding 65% of volume
