Which function is not associated with the excretory system?

The function of producing energy is not associated with the excretory system. The excretory system primarily involves processes related to the removal of waste products from the body, the filtering of blood to eliminate toxins and excess substances, and regulating various aspects of body homeostasis, including blood pressure. In contrast, energy production primarily takes place in the cells through metabolic processes, particularly cellular respiration, which occurs in the mitochondria. This is more aligned with the functions of the digestive and respiratory systems, where nutrients and oxygen are supplied for energy production. Thus, removing waste, filtering blood, and regulating blood pressure are key roles of the excretory system, whereas producing energy does not pertain to its functions.