Intro To The Cardiovascular System Flashcards
What is the cardiovascular system used for?
Carrying blood and transporting nutrients to muscles and organs and transporting away toxic stuff and hormones and immune cells
What is passive diffusion?
Random, unidirected thermal movement of molecules
What is the passive diffusion equation (described- like in words)
Time needed to diffuse a given distance is proportional to the square of the distance
What is systole?
Contraction
What is diastole?
Relaxation
What is the pressure in the aorta?
> 100mmHg
What is the pressure in large veins?
5-10 mmHg
What is the formula for cardiac output?
Heart rate x stroke volume
How much blood is pumped at rest?
5 litres/ min
How much blood is pumped when exercising?
20 litres/minute
What is blood flow proportional and inversely proportional to?
Proportional to the pressure across blood vessels
Inversely proportional to resistance of the blood vessels
What are the four main functional groups of blood vessels and what are their functions?
- Arterioles (resistance vessels) - control arterial BP and regulate local blood flow
- venules and veins (capacitance vessels) - control filling pressure of the heart and to provide a reservoir of blood
- arteries (elastic vessels) - accommodate stroke volume and convert ejection into continuous flow
- capillaries (exchange vessels) - nutrient delivery to cells, tissue, water and lymph formation and removal of metabolic waste
What is the pressure in veins?
3-12 mmHg
How is it that blood slows down in the capillaries?
The cross sectional area increase, so it can slow to allow gas/nutrient exchange to occur
What % of blood is in the veins at any given time?
65%
