Overview

A network of glands that make/release hormones:

Mental model:

You can view the Endocrine system as a balancing act. It works with feedback loops;

eg (metabolic balance):

Receptor cells notice thyroxine below a certain level so Hypothalamus releases Thyrotropin-releasing hormone (TRH) so that the pituitary gland knows to release Thyroid-stimulating Hormone (TSH) which causes the Thyroid gland to start producing thyroxine finally this stops the hypothalamus from releasing more TRH negative feedback loop finished, voila