Immune system

Immune system is a complex network of cells, tissues, and organs that work together to defend the body against harmful invaders such as bacteria, viruses, and disease-causing parasites. These invaders are called pathogens. The immune system's primary task is to recognize and eliminate these pathogens.

Overview

The immune system is composed of two main parts: the innate immune system and the adaptive immune system. The innate immune system is the body's first line of defense against pathogens. It includes physical barriers like the skin and mucous membranes, as well as cells and proteins that attack foreign substances in the body. The adaptive immune system, on the other hand, is responsible for the body's ability to recognize and remember specific pathogens in order to provide long-lasting immunity.

Components of the Immune System

The immune system is made up of various components, including white blood cells, antibodies, the complement system, the lymphatic system, the spleen, the thymus, and the bone marrow. Each of these components plays a crucial role in the body's defense against pathogens.

White Blood Cells

White blood cells, also known as leukocytes, are key players in the immune system. They are produced in the bone marrow and are part of the body's response to infection and disease. There are several types of white blood cells, including neutrophils, lymphocytes, monocytes, eosinophils, and basophils.

Antibodies

Antibodies, also known as immunoglobulins, are proteins produced by the body in response to an infection. They are capable of recognizing and neutralizing specific pathogens.

Complement System

The complement system is a part of the immune system that enhances the ability of antibodies and phagocytic cells to clear pathogens from an organism.

Lymphatic System

The lymphatic system is a network of tissues and organs that help rid the body of toxins, waste and other unwanted materials. It is also responsible for transporting lymph, a fluid containing infection-fighting white blood cells, throughout the body.

Spleen

The spleen is an organ that filters the blood, removes old red blood cells, and holds a reserve of blood in case of hemorrhagic shock.

Thymus

The thymus is a specialized primary lymphoid organ of the immune system where T cells mature.

Bone Marrow

Bone marrow is the flexible tissue in the interior of bones that produces blood cells.

Function of the Immune System

The immune system's primary function is to defend the body against pathogens. It does this by recognizing foreign substances in the body and launching an immune response to eliminate them. This response can involve a variety of cells and mechanisms, depending on the nature of the pathogen and the body's previous exposure to it.

Disorders of the Immune System

Disorders of the immune system can lead to autoimmune diseases, inflammatory diseases, and cancer. Autoimmune diseases occur when the immune system mistakenly attacks the body's own cells. Inflammatory diseases occur when the immune system overreacts to a perceived threat, causing excessive inflammation. Cancer can occur when the immune system fails to eliminate cells that have become abnormal and start to multiply uncontrollably.

See Also

• Innate immune system
• Adaptive immune system
• White blood cells
• Antibodies
• Complement system
• Lymphatic system
• Spleen
• Thymus
• Bone marrow
• Autoimmune diseases
• Inflammatory diseases
• Cancer

Immune system Resources
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