Lymphocytes are the cells that produce antibodies.

Lymphocytes are a type of white blood cell that are a crucial part of the immune system. They are responsible for recognizing and destroying foreign substances, such as bacteria or viruses, in the body.

There are two main types of lymphocytes: B cells and T cells. B cells are responsible for the production of antibodies, which are proteins that specifically bind to foreign substances and help to neutralize them. Antibodies are also known as immunoglobulins.

B cells are produced in the bone marrow and mature in the lymphoid tissues, such as the spleen and lymph nodes. When a B cell encounters a foreign substance, it binds to it and internalizes it. The B cell then processes the foreign substance and presents it to helper T cells, which activate the B cell.

Once activated, the B cell undergoes a process called clonal expansion, in which it divides rapidly and produces a large number of identical B cells. These B cells then differentiate into plasma cells, which are responsible for the production and secretion of antibodies. Plasma cells produce and release large amounts of antibodies into the bloodstream, where they can circulate and bind to foreign substances, marking them for destruction by other immune cells.

In addition to producing antibodies, B cells can also differentiate into memory B cells. Memory B cells are long-lived and can quickly mount a strong immune response upon re-exposure to a previously encountered foreign substance. This is the basis for the effectiveness of vaccines, which stimulate the production of memory B cells.

In conclusion, lymphocytes, specifically B cells, are the cells that produce antibodies. They play a crucial role in the immune response by recognizing and neutralizing foreign substances in the body.