Explain specific defence mechanism, Science

Assignment Help:

Explain Specific Defence Mechanism

In the section on white blood cells, we learnt that whenever a germ or infection enters our body, the WBCs snap to attention and destroy the culprit. How does a white blood cell know what to attack and what to leave alone? Why doesn't a white blood cell attack every cell in the body? The answer to these questions lies in the discussion below.

The specific defence mechanism provides protection against specific foreign materials. The important characteristic is that its cells (lymphocytes) have an ability to recognize body's own cells and macro molecules (self) from those which are foreign invaders (non self ). It tolerates the 'self' but destroys the 'non self'. The lymphocytes bearing receptor is specific for self i.e. molecules already present in the body, are either made non-functional or destroyed by programmed cell-death known as apoptosis. The lymphocytes that react to non self i.e. foreign molecules are left to function in immune responses.

So, you realize that there is a system built into all of the cells in our body that marks the cells in our body as "self '. Anything that the immune system finds that does not have these markings (or that has the wrong markings) is definitely "not self" and is therefore a fair game. This system is called the Major Histocompatibility Complex (MHC).


Related Discussions:- Explain specific defence mechanism

Food web, Food Web: Within an ecosystem,  there are many different food...

Food Web: Within an ecosystem,  there are many different food chains. Some organisms may be involved in several of the food chains at the same time. So a number of food chains

Food security, discuss determinants of food security

discuss determinants of food security

Explain neutrophils -types of white blood cells, Explain Neutrophils Th...

Explain Neutrophils They form about 50-70% cells. They have fine dust like particles in the cytoplasm which stain purplish. Tissues, cells damaged by the invading microbes rele

Aprons for personal protective devices, Aprons : Additional protection, su...

Aprons : Additional protection, such as a rubber apron is recommended for work with appreciable amounts of chromic acid, hydrofluoric acid and other highly corrosive liquids.

Explain the law of diminishing return, Explain the law of diminishing retur...

Explain the law of diminishing return. The increase in the yield by a unit increase of the deficient factor is proportional to the decrease from maximum.

Report, I need to write a report of 3pages

I need to write a report of 3pages

Ethical issues concerning use of animals for experimentation, Ethical issue...

Ethical issues concerning use of animals for experimentation and educational purposes (i) Animals procured, handled and looked after according to the regulatory principles laid

Explain the hyperparathyroidism, Explain the Hyperparathyroidism Hyperp...

Explain the Hyperparathyroidism Hyperparathyroidism may occur due to a tumour in one or more of the parathyroid glands. In this condition, the calcium level of the blood increa

To show that liquids exert pressure, To show that liquids exert pressure ...

To show that liquids exert pressure Connect two 15 cm lengths of glass tubing or two transparent plastic soda straws with a short length of rubber tubing and attach them to an

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