Final answer:
In the endocrine system, chemicals called hormones are secreted into the blood to regulate organism physiology. They act as messengers to orchestrate bodily functions and maintain homeostasis.
Step-by-step explanation:
In endocrine system regulation of organism physiology, chemicals called hormones are secreted into the blood. These hormones are chemical messenger molecules that are produced by endocrine glands. Once released, they circulate in the bloodstream to reach target cells that possess specific receptors for these hormones. For example, the pancreas releases insulin to regulate blood glucose levels, the adrenal glands secrete epinephrine and norepinephrine for stress responses, and the thyroid gland produces thyroid hormones to control metabolic rates. The endocrine system is crucial for coordinating and integrating body responses, maintaining homeostasis by affecting many different systems and organs.