Lecture Sixteen- Monday, February 8 , 2010 th
FLOW = AREA X MEAN VELOCITY
Flow must always stay constant, therefore:
Flow through large arteries the same as through aorta, but smaller cross
sectional area. Therefore the velocity is fast.
Flow through smaller vessels (largest cross sectional area), speed is slow. Not all pressure is hydrostatic
-Tube with a stopper: squeeze end, pressure is constant
-Remove stopper: not constant -First attempt to measure arterial pressure.
-Hollow tube stuck into carotid artery, blood ascended. The blood continues to go up
in the beginning, but as it goes up and up hydrostatic pressure becomes equal to the
arterial pressure, level of blood in the tube will no longer rise.
Central Venous Pressure
-The pressure in the veins.
-CVP= 5-10 cm H20 memorize!
-Clinically the Jugular vein is use