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

Phylum Coelenterata, What is the adaptative radiatoin of coelenterates

What is the adaptative radiatoin of coelenterates

Hypoglycemic effects of dietary factor, Define Hypoglycemic effects of Diet...

Define Hypoglycemic effects of Dietary Factor with antinutritional effect? Of the different carbohydrate foods tested for starch digestibility and blood glucose response, those

Where in leaves the photosynthetic tissue often located, Where in the leave...

Where in the leaves is the photosynthetic tissue often located? The major photosynthetic tissue is the photosynthetic parenchyma (also called as chlorenchyma, do not confuse wi

Explain about the paediatric and geriatric nutrition, Explain about the Pae...

Explain about the Paediatric and Geriatric Nutrition? Every stage has its unique requirements due to different changing needs. Adequate and optimum nutrition support is very im

Explain about oral glucose tolerance test, Q. Explain about Oral Glucose To...

Q. Explain about Oral Glucose Tolerance Test? This is most commonly used diagnostic test particularly for identifying new and ‘at risk' individua1s.Thi.s test is carried out af

What are transcription process and the replication processes, Q What are th...

Q What are the differences and similarities between the transcription process and the replication processes? A DNA polynucleotide chain serves up as a template in the replication (

Biodiversity, composition of aquatic animals what are their groupings

composition of aquatic animals what are their groupings

Genetics, What is pedigree analysis . How to solve the complicated question...

What is pedigree analysis . How to solve the complicated questions of pedigree . How to identify wheather it is dominant or reccessive its genotype

Uses of microbes in industry-citric acid, Normal 0 false fals...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

Major endocrine glands of the human body, Q. What are the major endocrine g...

Q. What are the major endocrine glands of the human body? The major endocrine glands of the human body are the hypophysis (or pituitary), the pineal gland (or pineal body), the

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