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

Food allergies, Food allergies: Food allergies are different from food ...

Food allergies: Food allergies are different from food fads. Certain fds  seem to have strange reactions on some people. Probably, you have come across a person who got skin ra

Stellar motion:, Stellar Motion: Stars are not fixed  in  the heavens. ...

Stellar Motion: Stars are not fixed  in  the heavens. They are moving within  the galaxies. The speed of a star moving toward or away from the Earth is indicated by a shift of

Explain agglutination - antigen-antibody interaction, Explain Agglutination...

Explain Agglutination - Detection of Antigen-Antibody Interaction Agglutination - If Ag is present on the surface of cells, or can be made to coat these surfaces of cells, thes

Define the rate and depth of breathing, Define the Rate and Depth of Breath...

Define the Rate and Depth of Breathing Do you know what the normal rate of breathing in adults is and what are the factors on which it depends? Well, the normal rate of respira

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

Livvy, what is inside a volcano

what is inside a volcano

Explain hiccup reflex actions - respiratory process, Explain Hiccup reflex ...

Explain Hiccup reflex Actions - Respiratory Process It is also a reflex associated with stimulation of sensory endings in the gastrointestinal tract or other tissue through irr

Explain time period can carbon-14 dates have, What time period can carbon-1...

What time period can carbon-14 dates have? Carbon 14 has a half-life of 5,730 years, and thus it can be used to date very precisely a large majority of things, particularly woo

Explain major histocornpatability complex (mhc), Explain Major Histocornpat...

Explain Major Histocornpatability Complex (MHC) Major histocompatability complex is also known as the Human Leukocyte Antigen (HLA). MHC molecules are important components of t

Air pollution by carbon monoxide, Air pollution by Carbon monoxide: Ca...

Air pollution by Carbon monoxide: Carbon monoxide is produced when organic materials such as gasoline, coal, charcoal, and trash are incompletely burnt. Virtually all stoves,

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