What is the function of memory cells in the immune system?

Memory cells play a crucial role in the immune system by providing long-term immunity. After an initial exposure to a pathogen, memory cells are formed, allowing the immune system to "remember" that specific pathogen. This memory enables the immune system to recognize and mount a quick and effective response if the same pathogen is encountered again in the future. This rapid response is critical for preventing reinfection and controlling the spread of disease.

In contrast, the other functions listed do not accurately reflect the role of memory cells. For example, the production of antibodies on first exposure is primarily the responsibility of naive B cells, not memory cells. Memory cells do not attack and destroy pathogens directly; their function is more about enhancing the speed and intensity of the immune response upon re-exposure. Additionally, regulating body temperature is not related to the activity of memory cells but involves other physiological processes within the body.