Define specific defence mechanism, Science

Assignment Help:

Define 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:- Define specific defence mechanism

Explain the primary processing of pulses, Primary processing of pulses ...

Primary processing of pulses Dry pulse seeds have a tight and fibrous seed coat (husk or skin) that envelops the cotyledons, which often is indigestible and may have a bitter

PROJECT, to study the presence of aroma taste,ph value and tannic acid of d...

to study the presence of aroma taste,ph value and tannic acid of diffrent tea leaves

Slogans on good eating habits for proper digestion, show me the slogans on...

show me the slogans on good eating habits for proper digestion

The carbon cycle, Carbon dioxide has been surmised as an significant compon...

Carbon dioxide has been surmised as an significant component in ceasing the last Ice Age, but its precise function has always been indecipherable as rising temperatures pondered in

Estimate the moisture content and density, 1. The composition of solid wast...

1. The composition of solid waste from a residential community is as follows: Component Percent by weight Combustibles ---

Reproduction, How does the intercourse work?

How does the intercourse work?

Hard and soft water in cleaning, Hard and soft water in cleaning Prepar...

Hard and soft water in cleaning Prepare two samples of dirty cloth. Wash one in soft water with soap unless it is clean. Wash the other cloth in hard water for the similar leng

Semiconductor devices and their uses, Semiconductor Devices and their Uses:...

Semiconductor Devices and their Uses: If a junction  is formed between a p-type and an n-type'semiconductor,  the device called a p- n  junction diode acquires a peculiar pppen

Physico-chemical properties of vitamin e, Physico-chemical properties of vi...

Physico-chemical properties of vitamin E are as follows: a)  Tocopherols are yellow, oily liquids. b)  They are freely soluble in fat solvents. c)  The  compounds  are

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