The innate immune system uses physical, chemical, and cellular defenses to serve as the first and second line of protection for the body.
True
False
The correct answer and explanation is:
The correct answer is True.
The innate immune system is the body’s first line of defense against infections and harmful pathogens. It consists of various physical, chemical, and cellular defenses that work together to protect the body from foreign invaders.
Physical defenses include the skin and mucous membranes, which act as physical barriers to prevent pathogens from entering the body. The skin is tough and impermeable to most microorganisms, while mucous membranes line body cavities that are exposed to the outside environment, such as the respiratory and gastrointestinal tracts. These membranes secrete mucus, which traps pathogens and prevents them from entering the body.
Chemical defenses involve substances that the body produces to neutralize or destroy pathogens. For example, sweat and sebaceous glands produce oils and acids that lower the pH of the skin, creating an inhospitable environment for many pathogens. In the stomach, gastric acid kills harmful bacteria that enter the digestive system. Additionally, antimicrobial proteins like defensins, lysozyme, and interferons also play key roles in fighting infections by breaking down the cell walls of bacteria or interfering with viral replication.
Cellular defenses include a variety of immune cells such as neutrophils, macrophages, and dendritic cells. These cells are always on the lookout for pathogens. When a pathogen is detected, these cells engulf and destroy it through a process called phagocytosis. Additionally, natural killer (NK) cells play an important role in recognizing and destroying infected or cancerous cells.
Together, these components of the innate immune system provide rapid and broad defense mechanisms to limit the spread of infections, often even before the adaptive immune system is activated. The innate immune system is always active and ready to respond to pathogens, and it serves as the body’s first line of defense against infection.