Explain briefly, the role of the following health aids:

Vaccines

Suppose a person develops the disease diphtheria. Comment upon the principle of the treatment he should receive.

Why is it important to know how the germs leave the body of a patient?

The figures A, B and C given below represent a kind of protective method in our body. Study the same and answer the following question:

(a) Name and define the process which occurs in figure A.

(b) What kind of blood vessel is shown in figure-A? Write its one specific structural feature.

(c) Name and define the process occurring in figure-B.

(d) What kind of blood cell is shown in the figures? Write its technical name also.

(e) Name the specific type of cell containing a 4 lobed nucleus of the category answered by you in part (4) above.