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

What do you mean by linnaeus binomial system, Q. What do you mean by Linnae...

Q. What do you mean by Linnaeus binomial system? Almost a century after Bauhin the great Swiss naturalist Carolus Linnaeus (1707-1778) published the two monumental works the "S

Peptide bond, PEPTID E BOND Peptide or amide bond is a linkage es...

PEPTID E BOND Peptide or amide bond is a linkage established condensation reaction between amino group of one amino acid and carboxylic group of the second amino acid.

How many different genotypes can the individual present, Considering a pair...

Considering a pair of homologous chromosomes containing a gene having two different alleles how many different genotypes can the individual present? If a gene of a diploid spec

Which part of heart serves as an effector, Which of the following serves as...

Which of the following serves as an effector, or as part of an effector, that functions in a negative feedback system? A. Nicotinic Acetylcholine Receptors (nAChR) in SA node c

What is tubal pregnancy, Q. What is tubal pregnancy? Many times fecunda...

Q. What is tubal pregnancy? Many times fecundation takes place in the Fallopian tubes in general the newly formed zygote is taken to the uterus where nidation and the embryonic

Biotechnology, Clonig,plasmid vectors,lambda&M13based vectors

Clonig,plasmid vectors,lambda&M13based vectors

Briefly explain about gelation, Explain Gelation Gelation, which occurs...

Explain Gelation Gelation, which occurs when yolk is frozen and thawed, is apparently due to the aggregation of yolk lipoproteins because  of the imbalance and shift in water.

Explain fats in biological compound, Explain Fats in biological compound ? ...

Explain Fats in biological compound ? Fats :   Monoglycerides, diglycerides, and triglycerides are fats consisting of a backbone of the alcohol molecule glycerol, consisting of

Name the foods to avoid in soft diet, Name the Foods to avoid  in soft die...

Name the Foods to avoid  in soft diet include: Fried foods and nuts, rich pastries and desserts, Raw  vegetables, Heavily spiced foods, Gas-forming vegetables, S

What is the vestibular system, What is the vestibular system? How does it o...

What is the vestibular system? How does it operate? The vestibular system is the part of the ear that participates in the control and regulation of the equilibrium of the body

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