Three lines of defense in the immune response

What are the Three Lines of Defense?

Three lines of defense

physical/chemical barriers

nonspecific resistance

Physical barrier

the skin and mucosa of the digestive and respiratory tracts, help eliminate pathogens

First line of defense

Second line of defense

Phagocytosis

this phenomenon utilizes a special type of immune cells called phagocytes. There are two types of phagocytes

phagocytes recognize and bind pathogens and then use the plasma membrane to surround and engulf pathogens inside the cell

Third line defense

Specific adaptive response

Aims at eliminating specific pathogens that have been encountered by the immune system previously