Theoritcal chemistry/physics Flashcards
Define pressure (P)
The force exerted per unit area
Define pressure gradient (∆P)
The difference in forces exerted at either side/end of a tube
Define flow (Q)
The volume of fluid passing a given level per unit timeml.s-1 or l.min-1
Define resistance
A force that opposes the flow of a substance
Define velocity
The rate of movement of fluid particles along a vessel cms/sec-1
Define laminar flow
When a fluid runs smoothly in layers along a tube and the layers are not disrupted
Define turbulent flow
When the layers in a flow are disrupted and mix
Define viscosity
The state of a fluid being thick due to internal friction
Define capacitance
The ability of the venous drainage system to store blood
What are the three factors that create turbulent flow?
Increased radius of the lumen
High velocity
Low viscosity
What are the three main factors contributing to an increase in resistance?
Decrease in radius of the vessel
Increasing the length of the vessel
Increasing the viscosity of the fluid
What are the three main factors contributing to an decrease in resistance?
Increase in the radius of the vessel
Decreasing the length of the vessel
Decreasing the viscosity of the fluid
What happens if resistance in the vessels increases?
Pressure needs to increase to maintain flow
