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

What are the factors affecting soil formation, What are the Factors Affecti...

What are the Factors Affecting Soil Formation  Parent materials formed due to weathering of rocks are transported from the place of their origin and re-deposited before they ar

Grant, what are the measurable causes of weather and how does weather impac...

what are the measurable causes of weather and how does weather impact our world?

Solar energy, Solar energy: The energy we get today from the fossil f...

Solar energy: The energy we get today from the fossil fuels like coal, is in reality sun's energy,  trapped in them millions of years ago. Plants make their food and grow bec

Explain the sensory decussation - feature of medulla, Explain the Sensory D...

Explain the Sensory Decussation - Feature of Medulla Some of the sensory nerves ascending to the cerebrum from spinal cord cross from one side to the other in the medulla. Card

Explain carbamoyl phosphate synthetase, Explain Carbamoyl Phosphate Synthet...

Explain Carbamoyl Phosphate Synthetase (CPSI) ? In the first step, the mitochondria1 enzyme Carbamoyl Phosphate Synthetase 1 converts the ammonia produced by glutamate dehydro

An experiment with a loop of thread, An experiment with a loop of thread ...

An experiment with a loop of thread Rinse a dinner plate methodically and then fill it with water. Make a loop with thread, open it a little and float it on the water. Touch th

The property of cleavage, Which  minerals best illustrates the property of ...

Which  minerals best illustrates the property of cleavage: Mica

State the role of algae - weathering, State the Role of Algae - Weathering ...

State the Role of Algae - Weathering Algae also plays an important role because it brings about increase in organic matter due to photosynthesis. The organic matter and CO2  fo

Excretion, how does excretory system of lizard work?

how does excretory system of lizard work?

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