If thymus gland is removed from the body of a person, his immune system will become weak. As a result the person's body becomes prone to infectious diseases.
Many microbial pathogens enter the gut of humans along with food. What are the preventive barriers to protect the body from such pathogens? What type of immunity do you observe in this case?
Many microbial pathogens enter the gut of humans along with food.
The preventive barriers to protect the body from such pathogens are as follows
(i) the mucus coating of the epithelium lining of the gut helps in trapping microbes entering the body.
(ii) saliva in the mouth and hydrochloric acid in gastric juice secreted by stomach prevent microbial growth.
This type of immunity is innate immunity. It is present from birth and is inherited from parents. The innate immunity remains throughout life.
Why is mother's milk considered the most appropriate food for a new born infant?
Colostrum contains several antibodies (especially IgA) which are absolutely essential for developing resistance for the new-born babies.
What are interferons? How do interferons check infection of new cells?
In response to viral infections our body produces glycoproteins called interferons. Such type of barriers of innate immunity is called cytokine barrier. Interferons protect the non-infected cells from further viral infection.
In the figure, structure of an antibody molecule is shown. Name the parts $A, B$ and $C$.
$$ \text { Structure of an antibody molecule } $$