Non-Specific Lines of Defense in the Body
The non-specific lines of defense in the body, also known as the innate immune system, provide an immediate response to foreign invaders without the need for prior exposure. These defenses are the body's first line of defense against pathogens and play a crucial role in protecting the body from infection.

Physical Barriers
- Physical barriers such as the skin and mucous membranes act as the first line of defense by preventing pathogens from entering the body. The skin forms a tough barrier that is difficult for pathogens to penetrate, while mucous membranes in the respiratory and digestive tracts trap pathogens and prevent them from entering the body.

Chemical Barriers
- Chemical barriers such as stomach acid, enzymes in tears, and antimicrobial peptides in sweat and saliva help to kill or inhibit the growth of pathogens. These chemicals create an inhospitable environment for pathogens, reducing the likelihood of infection.

Cellular Defenses
- Cellular defenses involve various types of immune cells, such as macrophages, neutrophils, and natural killer cells, which work together to identify and destroy pathogens. These cells can engulf and digest pathogens, release toxic chemicals to kill pathogens, or target infected cells for destruction.

Inflammatory Response
- The inflammatory response is a non-specific defense mechanism that helps to eliminate pathogens and repair damaged tissues. It involves the release of inflammatory mediators, increased blood flow to the affected area, and recruitment of immune cells to the site of infection.

Fever
- Fever is another non-specific defense mechanism that helps to fight infection by raising the body's temperature. This increase in temperature can inhibit the growth of certain pathogens and enhance the activity of immune cells.
In conclusion, the non-specific lines of defense in the body work together to provide immediate protection against pathogens and support the overall function of the immune system. These defenses are essential for maintaining health and preventing infection.