Viscosity - blood flow, Biology

Assignment Help:

Viscosity - Blood Flow

The resistance to flow in a tube results from inner friction in the fluid i.e. the viscosity. We all know that water and sugar syrup do not flow at the same rate from a bottle. We can say that water has low viscosity and syrup, a high viscosity. For convenience viscosity of a fluid is expressed relative to the viscosity of water. Blood plasma has a relative viscosity of 1.8 mostly as a result of the 7% dissolved proteins. Whole blood is more viscous because of the cells in it, at 37?C, relative viscosity of mammalian blood is between 3 and 4. Therefore, because of the presence of RBC blood behaves as though it is 3-4 times more viscous than water. However, blood does not behave as expected of a viscous fluid.

Its relative viscosity changes with decreasing radius of the blood vessels. In fact in tubes less than 0.3 mm in diameter the relative viscosity of blood approaches that of the plasma, therefore, it flows more easily. In flowing blood, we find that the red cells tend to accumulate in the centre. This accumulation leaves the wall relatively free of cells, therefore, the viscosity in the centre is more than at the sides. Since flow is inversely related to viscosity, flow at the walls will increase slightly and will decrease at the centre slightly. Another peculiar aspect of blood flow in capillaries is that often the capillary diameter is smaller than RBC and the RBCs easily change shape to pass through the capillary. This gives rise to a very different type of flow - bolus flow in which the red cells act as a plug that causes rapid increase in liquid along the walls of the capillary and thus help in the renewal of the diffusible substances in this layer.


Related Discussions:- Viscosity - blood flow

Explain saturated fatty acids, Explain saturated fatty acids Some of th...

Explain saturated fatty acids Some of the more significant saturated fatty acids with their systematic and common names are listed in table, and some of the unsaturated fatty a

Symbiotic nitrogen fixers - nutrient cycles, Symbiotic Nitrogen Fixers - Nu...

Symbiotic Nitrogen Fixers - Nutrient Cycles Of the symbiotic nitrogen fixing bacteria, species of Rhizobium form root nodules in legumes and are the most studied nitrogen fixe

Explain how a human eye is working for the body, Explain how a human eye is...

Explain how a human eye is working for the body. Every tissue in the body requires basic components which are either derived from the body itself or we acquire them from extern

Corpus luteum in human females.., what is the fate of corpus luteum if egg...

what is the fate of corpus luteum if egg gets fertilised ?

Draw a graph for an iv multiple infusion of a drug, Draw A graph for an IV ...

Draw A graph for an IV multiple infusion of a drug, and label on the graph where the trough (predose) blood draw would be collected and where the peak (postdose) blood draw would b

Explain what is periodontal condition, Explain what is Periodontal Conditio...

Explain what is Periodontal Condition? If intact attachment apperatus without pocket, time is critical direction toward non-surgical repair to prevent periodontal breakdown

Determine the method of recombination, Which of the following is a false st...

Which of the following is a false statement regarding the method of recombination or crossing-over? A. Crossing-over takes place during prophase I of meiosis B. Recombinatio

Homeostasis, using a specific example describe how hormones have an importa...

using a specific example describe how hormones have an important role in the regulation of body functions and also, what happens if there is an over secretion or an under secretion

Individuals with tyrosinenmia, Individuals with tyrosinenmia have food patt...

Individuals with tyrosinenmia have food patterns very similar to the one for PKU discussed above. PKU is more common than tyrosinemia. Foods that are high in tyrosine and phenylala

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd