Cardio 2 and 3 Flashcards
What is a simple definition of volume?
How much blood there is and where it is
What is the total blood volume (on average)
5L
What is 1 blood unit?
450 mL
What is one stroke volume and how much is it?
The blood pumped with each beat
70 mL
What is the percentage of blood in the arterial system?
18% (about 0.9L)
What is the percentage of blood in the veinous system?
61% (about 3L)
What is the percentage of blood in the heart and pulmonary circulation?
9%
12%
What is cardiac output? what is the formula?
the amount of blood the heart pumps in one minute
CO = SR X SV
What is the venous return? what is the formula?
the flow of blood back to the atrium, and must be equal to cardiac output
VR = CO
What is the average CO?
CO = 5000 mL/min
Explain the series-parallel circuit.
The blood flow is the same in the pulmonary and systemic circulation. However, in the systemic circulation, the blood flow is divided to organs depending on how much blood they need
How is flow measured?
Flow = V/T
What is the flow formula with velocity?
Flow = Area X mean velocity
Why do we measure flow with mean velocity instead of velocity?
Flow velocity is not constant within a blood vessel; it is bigger in the middle and slower in the surround
List the vessel types in size order
Aorta
Arteries
Arterioles
Capillaries
Venules
Veins
Vena cava
Because we have a branching network, how does the total area vary? How does this affect velocity?
It increases dramatically in the smaller branches
Since velocity = F/A, velocity drops significantly at the capillaries
What are the advantages of having a branching network? (3)
- All cells are close to the capillary
- High total surface area for the capillary network increases the rate of diffusion
- Low velocity gives more time for diffusive exchange
What is normal arterial blood pressure, and what does each number represent?
120/80
Systole pressure / diastole pressure