What protects against infections?

The immune system protects against infections. It is a complex network of cells, tissues, and organs that work together to defend the body from harmful pathogens, such as bacteria, viruses, parasites, and fungi.

The immune system has several lines of defense, including:

* Physical barriers: The skin and mucous membranes act as physical barriers that prevent pathogens from entering the body.

* Chemical barriers: The stomach acid and other chemicals can kill or inhibit the growth of pathogens.

* Cellular defenses: White blood cells, such as neutrophils and macrophages, can engulf and destroy pathogens.

* Humoral defenses: Antibodies are proteins that can bind to pathogens and prevent them from infecting cells.

* Cytokines: These chemical messengers help to coordinate the immune response and recruit immune cells to the site of infection.

The immune system is constantly adapting and learning, so it can better recognize and respond to new pathogens. This is why vaccines are so important - they help to train the immune system to recognize and fight off specific pathogens.

A healthy immune system is essential for maintaining good health and preventing infections. A weakened immune system can increase the risk of developing infections, some of which can be life-threatening.