Question

2. Blood with a hematocrit of 45% flows through a 10 micrometer diameter tube. Flow is directly proportional to the pressure difference across the tube and inversely proportional to the apparent viscosity of blood. Compare the actual pressure difference across the tube with the pressure difference necessary to provide the same flow if the apparent viscosity in the tube remained the same as the apparent viscosity in a very large tube. Discuss implications of the Fahraeus-Lindqvist effect on the work of the heart.

Answer 1

They will be decrease in apparent viscosity that occurs when blood flow through a tube of smaller diameter.In large tube as radius increases it will reduce resistance in turn viscosity decreases.flow only occur when a pressure difference exits .

A decrease in apparent viscosity as the vessel diameter decreases also occurs. Erythrocytes move over to the centre of the vessel ,leaving only plasma near the wall of vessel thus it lower the effect viscosity of whole blood ,reduce in flow resistance within capillary.