Final answer:
The combining form meaning immune, protected, safe is 'immun/o'. It represents the body's capability to resist pathogens due to memory lymphocytes (B or T cells) and is an essential part of maintaining health. Immunity can be active or passive and involves immunoglobulins and immunological memory.
Step-by-step explanation:
The combining form that means immune, protected, safe is immun/o. The concept of immunity in medicine refers to the body's ability to resist a pathogen due to the formation of memory lymphocytes, which are either B or T cells, that were created in response to a prior infection with that specific pathogen. This biological defense mechanism is essential for maintaining health and preventing disease. The immune system comprises various barriers, cells, and soluble mediators that work together to respond to infections caused by pathogenic organisms.
Immunity can be either active or passive and involves components like immunoglobulins (antibodies), which occur in five main classes, and immunological memory, which is the ability of the adaptive immune response to mount a stronger and faster immune response upon re-exposure to a pathogen. Conditions such as agammaglobulinemia, HIV/AIDS, and severe combined immunodeficiency affect the immune system's capacity to function properly and defend the body against infections.