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

How does aldosterone act and where is it produced, How does aldosterone act...

How does aldosterone act and where is it produced? Aldosterone is a hormone that acts upon the nephron tubules stimulating the resorption of sodium. Thus it contributes to the

Biosynthesis of amino acids, Microorganisms and Plants can synthesize all o...

Microorganisms and Plants can synthesize all of the 20 standard amino acids. Mammals, furthermore, cannot synthesize all 20 and must obtain some of them in their diet.  Those  amin

Explain the radiographic examination of prothesis, Radiographic Examination...

Radiographic Examination Radiographs are an important tool to evaluate the bone levels, health and implant integrity.  Annual radiographs following treatment are recommended in

Cardio pulmonary resuscitation, CARDIO PULMONARY RESUSCITATION: Cessat...

CARDIO PULMONARY RESUSCITATION: Cessation of cardiac activity is determined by  inability to palpate a central pulse,  unresponsiveness and Gnea. CPR consists of  measures for

Explain ganciclovir, Ganciclovir  (Cytovene) IV ganciclovir is approved...

Ganciclovir  (Cytovene) IV ganciclovir is approved for both induction and maintenance treatment of cytomegalovirus (CMV) retinitis in immunocompromised patients and for prevent

Ocean thermal energy, The oceans and absorb solar radiations. There exit a ...

The oceans and absorb solar radiations. There exit a temperature difference between surface and deep ocean water. Ocean thermal energy conversion plants convert the solar energy

Describe about the secondary prevention - food allergy, Describe about the ...

Describe about the Secondary Prevention - Food Allergy? Secondary allergic preventive measures will focus on: Initiating prospective surveillance of infants, young child

Cells, what are golgi apparatus

what are golgi apparatus

Difference between lamarckism and neo-lamarckism, DIFFERENC E BETWEEN LAMA...

DIFFERENC E BETWEEN LAMARCKISM AND NEO-LAMARCKISM - S.No Lamarckism Neo-Lamarckism 1. It refers of the original

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