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

Briefly explain about pickled vegetables, Briefly explain about Pickled veg...

Briefly explain about Pickled vegetables These are produced by spontaneous lactic acid fermentation. Fermentation improves the digestibility and wholesomeness  of the product.

Zoonoses disease-chikungunya, Chikungunya Chikungunya, a metazoonosis,...

Chikungunya Chikungunya, a metazoonosis, is caused by chikungunya virus belonging to genus Alphavirus of the family Togavirideae. The virus is transmitted by infected mosquito

Animal reproduction, Animal Reproduction - Reproduction is the ability ...

Animal Reproduction - Reproduction is the ability to produce new organism of its own type. It is meant to increase their number. Reproduction includes - (i) Replication o

Define maxillofacial prosthodontics, Q. Define Maxillofacial Prosthodontics...

Q. Define Maxillofacial Prosthodontics? Dental implants are now been increasingly used for Maxillofacial Prosthodontics. Maxillofacial Prosthodontics involves the prosthetic re

What is the normal duration of the menstrual cycle, What is the normal dura...

What is the normal duration of the menstrual cycle? How does the calendar contraceptive method work? The normal duration of the menstrual cycle is 28 days but it can vary betwe

Free racials, Which of the following could potentially be a free radical? A...

Which of the following could potentially be a free radical? Answer oxygen (atomic number 8) helium (atomic number 2) neon (atomic number 10)

Explain false positive tests, Q. Explain False Positive Tests? As ST de...

Q. Explain False Positive Tests? As ST depression has been equated with CAD, patients with this finding who have less than a critical coronary narrowing has been called false p

Define about the anthropometry method, Define about the Anthropometry Metho...

Define about the Anthropometry Method? Anthropometry refers to the measurement of the size and proportions of' the human body. Anthropometric prediction equations estimate body

Dot blot, Dot blot  is the technique for measuring the amount of one pertic...

Dot blot  is the technique for measuring the amount of one perticular DNA or RNA in the highly complex mixture. The samples are spotted onto the hybridization membrane (like nitroc

Determine the benedict test, Determine the Benedict's Test Glucose in u...

Determine the Benedict's Test Glucose in urine is detected by Benedict's method and the test is known as Benedict's test. This test is used to detect glucose in urine (Glycosur

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