Which part of the nervous system contributes to the intense activity of most internal organs and systems, especially in extreme situations?

The main division of the central nervous system that regulates other endocrine glands is the pituitary gland. The pituitary gland is under the control of the hypothalamus. It produces hormones that stimulate the adrenal glands, thyroid gland, and mammary glands. It produces growth hormone and a hormone that regulates water-electrolyte metabolism – vasopressin or antidiuretic hormone. During stress, activating hormones are intensely released into the bloodstream and cause an increase in blood pressure, sugar levels, and heart function.