Question

What is immune system? What are its main kinds? What is the role of 'B' type and 'T' type cell in the body defensive mechanism.

Answer 1

The immune system includes the processes and the structures that provide a defence against disease-causing pathogens. Immunity may be grouped into two types:

1. Innate immunity- It includes the defence elements with which an individual is born i.e. it is present right from the birth. It consists of various types of barriers that prevent the entry of foreign particles.

2. Acquired immunity- It is acquired after birth and consists of specialized cells called B cells or T cells and antibodies that circulate in the body

Role of B cells- These cells are involved in humoral response and also produce memory cells. B cells release antibodies that attack the foreign pathogens.

Role of T cells- These cells are involved in cell-mediated Immunity. These cells recognise the proteins that have been processed within antigen presenting cells and presented on the cell surface in the form of major histocompatibility complex or MHC.