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 ablation, What is ablation? Ans)  Ablation is a technological t...

What is ablation? Ans)  Ablation is a technological term for the loss of snow and ice from a glacier. The process happens by a combination of the two physical processes, meltin

A simple balance of pulley, A simple balance Suspend a ruler by loops o...

A simple balance Suspend a ruler by loops of cord a short distance above a table top, as shown in the diagram. When the ruler is in balance, place identical coins in dissimilar

Genital and Reproductive Function, Genital and Reproductive Function: J.Y...

Genital and Reproductive Function: J.Y. is a 43-year-old woman who has detected a lump in the upper outer quadrant of her left breast while performing her monthly self-breast exam

Softening water with chemicals, Softening water with chemicals Try mak...

Softening water with chemicals Try making suds with a half test tube of hard water and a few drops of soap solution. Next boil a same sample and again try to make suds by usin

Kinetic energy, How is energy from food and energy from gasoline different?...

How is energy from food and energy from gasoline different?

Explain the process of packaging and storage of oil, Packaging and storage ...

Packaging and storage of oil Rancidity can cause the oil to deteriorate and develop off-flavors during storage. Using clean, dry containers, which exclude light and heat, and p

Explain the water cycle, The Water Cycle Heat some water unless it is n...

The Water Cycle Heat some water unless it is near the boiling point. Place it in a drinking glass and rotate the glass so as to moisten the sides right to the top. Place some v

Explain the hypoxic hypoxia, Explain the Hypoxic Hypoxia It is a hypoxi...

Explain the Hypoxic Hypoxia It is a hypoxia resulting from defective oxygenation of the blood in the lungs. It is a problem in high altitudes where pO 2 of the arterial blood

Animals, what are the kinds of animals?

what are the kinds of animals?

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