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

Atoms and elements, why the atoms in neon gas do no join up in the same way...

why the atoms in neon gas do no join up in the same way that hydrogen atoms do?

Explain the mucous membrane, Explain the Mucous Membrane This layer is ...

Explain the Mucous Membrane This layer is lined by the epithelial cells. Parts of the tract which are subject to mechanical injury, the layer consists of stratified squamous ep

What makes a mineral a mineral explain properties of mineral, what makes a ...

what makes a mineral a mineral? The properties of minerals: There are seven main properties that are used to describe and classify any mineral found. All seven properties are

Conversion of oxaloacetate to phosphoenolpyruvate, Conversion  of  oxaloa...

Conversion  of  oxaloacetate to phosphoenolpyruvate Conversion  of  oxaloacetate to phosphoenolpyruvate:  In  this  reaction, oxaloacetate and guanosine triphosphate (GTP) are

Decline os science, explain the factors that led to the decline of science ...

explain the factors that led to the decline of science in europe during iron agen..

Explain the adrenocorticotropic hormone (acth), Explain the Adrenocorticotr...

Explain the Adrenocorticotropic Hormone (ACTH) ACTH, also known as corticotrophin, is a polypeptide and is synthesized by corticotroph cells of the anterior pituitary gland. It

Role of antibody mediated immune system, Role of Antibody Mediated Immune S...

Role of Antibody Mediated Immune System The AMlS defends the body against free viruses, bacteria with polysaccharide capsules and toxins that enter the body fluids (blood and l

Discuss in brief about the red soils, Discuss in brief about the Red soils ...

Discuss in brief about the Red soils Red soils are characterised  by a rusty red colour due in most cases to the presence of various oxides of iron.  They are either formed  in

Explain the digestion of food, Explain the Digestion of Food Salivary a...

Explain the Digestion of Food Salivary amylase or ptyalin acts on cooked starches (polysaccharides) and changes them into maltose as shown herewith. Boiled starch → soluble

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