Question

how does the immune system, nervous system and endocrine system take part during thermoregulation during a fever? how does 2 systems work together to retain homeostasis?

Answer 1

Thermoregulation, a process which maintains body internal core temperature and helps to return your body to homeostasis.

Hypothalamus (endocrine system) is a part of brain that controls thermoregulation. When it senses your internal temperature becoming too low or high, it sends signals to your muscles, organs, glands, and nervous system.

The presence of pathogens like bacteria and viruses is sensed by innate immune cells (immune system) in the blood, produces cytokines and prostaglandins such as COX2 which is expressed in endothelial cells results in local PGE2 production in hypothalamus, and this PGE2 acts through EP3 receptors expressed in the median preoptic (MnPO) to effect changes in body temperature.

When the body temperature is increased resulting in activation of autonomic nervous system causes:

Sweating by acetyl choline resulting in sympathetic nervous system activation, shivering, dilation or constriction of blood vessels at skin surface by norepinephrine, insulation and breakdown of brown adipose tissue to produce heat are the functions of nervous system during thermoregulation.