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 is the meaning of ''rock'' and ''mineral'', The meaning of 'rock' and ...

The meaning of 'rock' and 'mineral' Develop the meaning of these two terms by a study of the specimens collected. A rock is usually regarded as mineral matter found in t

Explain pantothenic acid (vitamin b5), Pantothenic acid (vitamin B5) P...

Pantothenic acid (vitamin B5) Pantothenic acid, also  known  as vitamin B5, is essential to  all forms of  life. Pure pantothenic acid was  first isolated as its calcium salt

Explain mouth to mouth respiration, Explain Mouth To Mouth Respiration ...

Explain Mouth To Mouth Respiration If no instrument is available, one's own lung may be used as a positive pressure pump. Air may be blown into the lungs of the subject by way

Healing touch of lasers, Healing Touch of Lasers: Contrast the above ...

Healing Touch of Lasers: Contrast the above application  of lasers with their uses in medicine where the laser is working wonders. A laser can be applied with almost perfect

Science, hi can you help me on my science

hi can you help me on my science

Conservation of mineral resources, Conservation of mineral resources: M...

Conservation of mineral resources: Mineral reserves are present in a limited quantity and they can be exhausted. At  the present rate of consumption many of  them will not last

Water consumption efficiency, my research topic is based on water consumpt...

my research topic is based on water consumption efficiency. I need definitions of the following keywords; efficiency consumption, water use behavior / pattern; water end uses, wat

GDP and GDP per capita, describe the differences between GDP and GDP per ca...

describe the differences between GDP and GDP per capita

Reproduction, Explain how the uterus supports the development of a baby dur...

Explain how the uterus supports the development of a baby during gestation.

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