👉 Infection is a complex biological process initiated when a pathogen, such as bacteria, viruses, fungi, or parasites, enters a host and begins to multiply or cause disease. The anatomy of infection involves several key components: the pathogen itself, which can invade tissues through various routes like inhalation, ingestion, or skin contact; the host's immune system, which responds to the invasion with both innate and adaptive defenses; and the site of infection, where pathogens colonize and interact with host cells. The innate immune response, involving physical barriers (like skin) and cells (such as macrophages and neutrophils), acts quickly to contain and eliminate the pathogen. If the infection persists, the adaptive immune system, comprising T cells and B cells, mounts a more specific and targeted attack. Pathogens can evade or manipulate the host's defenses, leading to chronic infections or systemic spread. The anatomy of infection also includes the microenvironment of the affected tissue, which can influence the severity and progression of the disease, as well as the body's healing processes.
