Final answer:
Minimal alveolar concentration (MAC) defines the potency of an inhaled anesthetic, indicating the concentration needed to prevent movement in 50% of patients in response to pain.
Step-by-step explanation:
Minimal alveolar concentration (MAC) defines the potency of an inhaled anesthetic. This is a standardized measure used to compare the strengths of anesthetic gases. Specifically, MAC is the concentration of anesthetic in the lungs that is needed to prevent movement in 50% of patients in response to a painful stimulus. It is a critical factor that anesthesiologists consider when determining how much anesthetic to administer to a patient. Factors such as age, body temperature, and the use of other drugs can affect an individual's MAC for a particular anesthetic.