Most involved in regulating and controlling body functions?

The nervous system is primarily responsible for regulating and controlling body functions. It consists of the central nervous system (brain and spinal cord) and the peripheral nervous system (nerves outside the brain and spinal cord). The nervous system coordinates and controls various processes such as movement, sensation, cognition, and homeostasis through the transmission of electrical signals between neurons. Additionally, the endocrine system also plays a crucial role in regulating body functions by producing hormones that act as chemical messengers to control various physiological processes.