Final answer:
After physical barriers like the skin are breached, the innate immune system responds with inflammation, engulfment of pathogens, and secretion of immune factors. Cells such as neutrophils, macrophages, and eosinophils actively work to neutralize the threat. The complement system also aids in destroying the invading pathogens.
Step-by-step explanation:
Physical barriers are the body's first defense against pathogens. When these barriers are breached, for example through skin abrasions or punctures, pathogens can enter the body. This prompts a response from the innate immune system, which includes inflammation, pathogen engulfment, and the secretion of immune factors and proteins.
Inflammation helps create a barrier against the spread of infection and assists in repairing tissue damage, while certain immune cells, like neutrophils and macrophages, act to engulf and destroy the invading pathogens. Other cells, such as mast cells and basophils, release chemicals that trigger and sustain the inflammatory response. Moreover, the complement system is part of the innate immune response, consisting of proteins that work with antibodies to burst the cell membranes of pathogens, leading to their destruction.
If pathogens are successful in penetrating the mechanical barriers like the skin and mucous membranes, they encounter these robust innate immunity responses, which work to quickly neutralize and remove the threat to maintain homeostasis and health.