Final answer:
The term the student is seeking is 'secondary immune response.' It's a rapid and powerful reaction of the adaptive immune system involving the activation of memory cells that have been retained in the body to quickly eliminate a previously encountered pathogen.
Step-by-step explanation:
The quick mobilization of the immune system you're describing is known as the secondary immune response. This response is more efficient and rapid than the primary immune response because of the immunological memory. After the first exposure to a pathogen, the adaptive immune system creates memory B cells and memory T cells. These cells are specific for the pathogen's antigens and remain in the body after the infection has been cleared. When the same pathogen tries to invade the body again, these memory cells recognize it and quickly mount a strong defense, usually preventing a full-blown infection and the occurrence of symptoms. This immunological memory is critical as it serves as the body's long-term protection against reinfection with the same type of pathogen.
The adaptive immune system is responsible for this response, which can be broken down into two types: cell-mediated response, handled by T cells, and humoral response, managed by B cells and antibodies. These components work together to attack pathogens directly or produce antibodies that enhance the removal of pathogens, leading to a rapid and powerful attack upon reexposure to the same antigen.
Therefore, the final answer in two-line explanation in 300 words: When the adaptive immune system encounters a pathogen for a second time, the quick and powerful secondary immune response occurs, involving the immediate activation of memory B and T cells that have been retained from the primary immune response to quickly target and eliminate the pathogen. This adaptive response effectively prevents the symptoms of infection by the rapid neutralization of the pathogen.</p>