<prompt> Answer this question truthfullyWhat does minimum alveolar concentration mean?  <response>: <reason> The MAC of a volatile substance is inversely proportional to its lipid solubility oil:gas coefficient, in most cases. This is the Meyer-Overton hypothesis. MAC is inversely related to potency i.e. high mac equals low potency.The hypothesis correlates lipid solubility of an anaesthetic agent with potency 1MAC and suggests that onset of anaesthesia occurs when sufficient molecules of the anaesthetic agent have dissolved in the cells lipid membranes, resulting in anaesthesia. Exceptions to the Meyer-Overton hypothesis can result from:convulsant property of an agent specific receptor various agents may exhibit an additional effect through specific receptors co-administration of Alpha 2 agonists dexmedetomidine andor opioid receptor agonists morphinefentanyl can decrease the MAC Mullins critical volume hypothesis positive modulation of GABA at GABA A receptors by barbiturates or benzodiazepines 