Your immune system is the body’s first and last line of defense against foreign substances, such as bacteria and viruses. The proteins in your immune system are used to recognize and fight these foreign substances. Most substances that come into contact with your body or fluids cannot enter your cells because they do not have the correct protein key to unlock the cell membrane.
Antibodies recognize and bind to these foreign substances, creating holes in the cell. The hole allows other chemicals to enter the cell, destroying it. Foreign substances entering the body can cause a condition known as an immune response. It’s a broad term that describes what happens when the body recognizes something it doesn’t think belongs there.
These foreign substances can be anything from a virus, to a cut that allows bacteria to enter the body and causes an inflammatory response in the area surrounding it. Keep on reading this blog so you will understand how the immune system recognizes infectious bacteria or substances that can cause cancer.
Structure Of The Immune System
The human body has an amazing immune system that protects us from harmful microbes and foreign substances.It is an incredibly complex system, comprising many different types of cells and molecular interactions. One of the most important functions it has is to recognize foreign substances and protect the body from them.
The immune system is made up of lymphocytes, white blood cells that are able to recognize foreign substances in the body. These immune cells are able to recognize and kill foreign invaders like bacteria or viruses, such as when a person gets a cold or the flu. It uses several different mechanisms to recognize pathogens and block their ability to infect the host.
The two systems that the immune system use against foreign substances
- Innate Immune System – is the first line of defense against foreign substances. It is nonspecific and exists in most animals in all body systems. Innate immunity begins when a pathogen, such as a bacterium or virus, attempts to enter the body.
- Adaptive Immune System – is a network of proteins and molecules that protects our body from foreign substances. This system is capable of identifying and destroying cells that have been altered by viruses and bacteria, which is why it’s able to halt infections. The adaptive immune system works by using T-cells and B-cells.
Three Types Of Immune System Recognition:
1. T-Cell: Recognizes foreign substances by the interaction between their respective MHC proteins and the foreign substance’s corresponding epitope.
2. B-Cell: Recognizes foreign substances through their interactions with antibodies and other plasma proteins.
3. Antigen: Presenting Cell: Includes macrophages, dendritic cells, Langerhans cells, and B-cells, which all present foreign substances to T-cells for recognition.
How Are Foreign Substances Recognized By The Immune System?
The immune system recognizes foreign substances and responds to them by producing antibodies.Antigens are foreign substances that trigger the immune system to produce antibodies against them.
Antigens are molecules that can be found on the surface of viruses, bacteria, cancer cells, pollen, transplanted organs, transplanted tissues, blood transfusions, and other similar substances. When the immune response identifies an antigen as foreign, it activates an antibody response to ensure that the body does not mistake it for a part of itself.
A substance is considered a foreign substance when it is not normally part of the body’s normal make-up. These substances can be anything from bacteria to cancer cells. Once these foreign substances are identified, the immune system uses a variety of ways to flush them out of the body.
The most common way that the immune system moves foreign substances out of the body is through the lymphatic system. This occurs in many parts of the body, including lymph nodes, tonsils, spleen, and thymus gland. The fluid produced by this process is called lymph fluid, which contains white blood cells for fighting off infections and germs.
Other mechanisms used by the immune system include inflammation, in which fluids cause swelling and redness in infected areas; hypersensitivity reactions, in which immune cells respond to certain proteins in an abnormal manner.
The immune system is an amazing thing. Its role in fighting foreign substances and infection is so critical that the entire human body has been designed to work together to fight off foreign substances. That being said, the immune system only “kicks into action” when foreign substances are recognized as such by white blood cells.
The human immune system serves to protect the human body against attacks of foreign substances by identifying and destroying infectious agents. It maintains barriers for defense.
If you haven’t already, check out my videos related to the immune system below!
Learning Biology with Dr. Vanessa, LLC 