Below is information about the structure and function of the feline immune system. We will tell you about the general structure of the immune system, how the immune system works in cats, common diseases that affect the immune system, and common diagnostic tests performed in cats to evaluate the immune system.
What Is the Immune System?
The immune system is a complex network of specialized cells and organs designed to defend the body against bacteria, viruses, toxins, parasites and any foreign material that invade the cat's body. Millions of different types of immune cells pass information back and forth, which results in a protective system that is always ready to produce an immune response that is fast and effective. The immune system is also a component of the lymphatic system.
Where Is the Immune System Located?
The organs of the immune system are located throughout the body. They are called lymphoid organs because they are frequently the site of growth, development and deployment of lymphocytes - white blood cells that are key operatives of the immune system.
Important components of the immune system are concentrated in the blood, thymus, lymph nodes, bone marrow, spleen, lungs, liver and intestines. When an infection starts in a location that has only a few components of the immune system, such as the skin, signals are sent throughout the body to call in large numbers of immune cells to the site of the infection.
What Is the General Structure of the Feline Immune System?
The organs of the immune system are connected with one another and with other organs of the body by a network of lymphatic vessels similar to blood vessels. Immune cells, proteins, and sometimes foreign particles are carried through these vessels in lymph, a clear fluid that bathes the body's tissues. Various components of the immune system are also linked by the circulatory system.
The major components of the immune system include:
What Are the Functions of the Cat's Immune System?
Types of Immune Responses in Cats
When exposed to a foreign substance or infectious agent, the immune system mounts two major immune responses, called nonspecific immunity and specific immunity. These responses occur in tandem and influence each other.
There are two main components of nonspecific immunity. One component is the phagocyte system, whose function is to ingest and digest invading microorganisms. The white blood cells primarily involved in phagocytosis are the neutrophils, monocytes and tissue macrophages. Another component is the natural killer (NK) cells, whose function is to kill some tumors, microorganisms and virally infected cells
Each B cell is programmed to make one specific antibody. When a B cell encounters its triggering antigen, it stimulates many large plasma cells (another form of white blood cell). Each plasma cell is like a factory for producing that one specific antibody.
What Are the Common Diseases of the Immune System in Cats?
Disorders of the immune system fall into three major categories: immune deficiencies, immune-mediated diseases, and cancer of the immune system.