The innate immune system is the body's first line of defense against foreign invaders, such as bacteria, viruses, and parasites. It is a part of the immune system that is always active and ready to defend the body from infection. It is made up of physical barriers, such as skin and mucous membranes, as well as specialized cells, proteins, and other substances that work together to identify and attack foreign invaders. It is the first line of defense that the body employs when it is exposed to a potential threat.
Physical Barriers
The body's physical barriers are its first line of defense against infection. The skin is the body's largest physical barrier, and it prevents most foreign substances from entering the body. Other physical barriers include the lining of the nose, mouth, and other openings, as well as the tears, saliva, and mucus that help flush out invaders.
Specialized Cells
The innate immune system also includes specialized cells that help to identify and attack foreign invaders. These cells, called phagocytes, are white blood cells that can engulf and digest foreign particles, such as bacteria and other pathogens. Other specialized cells, called natural killer cells, can recognize and destroy cells that have been infected with a virus.
Proteins and Other Substances
The innate immune system also includes proteins and other substances that help to detect and fight foreign invaders. These include cytokines, which are molecules that signal the body to begin an immune response, and interferons, which are molecules that can inhibit the growth of viruses. Additionally, the body produces antibodies, which are proteins that recognize and bind to foreign particles, marking them for destruction.
The innate immune system is the body's first line of defense against foreign invaders and is made up of physical barriers, specialized cells, proteins, and other substances that work together to identify and attack foreign invaders. This system helps to protect the body from infection and disease.