Understanding Tertiary Immunity: Lymphocytes, Antibodies, and Vaccines

Tertiary Barriers: The Specific Immune Defense

The tertiary barrier, the body's last line of defense, comprises organs like the thymus, spleen, and lymph nodes. These organs produce or complete the development of two types of leukocytes: B lymphocytes and T cells. These cells act on pathogens in a highly specific manner, can distinguish between self and non-self (antigen), and retain memory.

Antigen Recognition and Attack

An antigen is any molecule genetically foreign to the body, meaning it is not recognized as self and has the potential to cause antibody formation. The recognition of antigens and the attack on the invader are coordinated actions carried out by macrophages, B cells, and T cells.

Antibody Production (Immunoglobulins)

B cells, stimulated by a special type of T lymphocyte, produce antibodies or immunoglobulins. These are special proteinaceous macromolecules that neutralize pathogens and generate immunity in the body.

Classes of Immunoglobulins

• IgM (LGM): The first formed in the newborn.
• IgG (LGG): Predominantly found in serum.
• IgE (LGE): Predominant in allergies.
• IgA (LGA): Predominates in saliva and breast milk.
• IgD (LGD): Function is largely unknown.

T Cells and B Cells Function

T Cells Maturation and Action

T cells mature in the thymus, where they prepare for their action or become immune-sensitized. In the presence of an antigen, they do not secrete antibodies into the blood; instead, they directly attack through the interaction of other somatic cells.

B Lymphocytes Maturation and Role

B cells mature in the bone marrow. They are responsible for synthesizing and releasing antibodies into the blood. The human body contains more than 100,000 million B cells, each secreting specific antibodies.

Active and Passive Immunity

Vaccines

Vaccines are antigens or mixtures of antigens that induce active immunity. They represent one of the most important social advances due to their ability to prevent certain infectious diseases.

Sera

Sera are inoculated at the beginning of any disease and provide immediate action. Serum immunity is of short duration, highly therapeutic, and applied when a person is suffering from a disease, such as cholera.

Accessory Glands in the Male Reproductive System

Cooper Glands Function

Cooper glands (also known as bulbourethral glands) are two exocrine glands of the human male reproductive system. They are homologous to the Bartholin's glands of women. These small glands are located below the prostate, and their function is to secrete an alkaline fluid that lubricates and neutralizes the acidity of the urethra before the passage of sperm into the ejaculate.