The endocrine system is a complex network of glands that produce and secrete hormones throughout the body. Hormones regulate various physiological processes such as metabolism, growth and development, sexual function, and mood. The major glands of the endocrine system include the pituitary gland, thyroid gland, parathyroid glands, adrenal glands, pancreas, and gonads (testes in males and ovaries in females).

The pituitary gland is often referred to as the master gland as it regulates the secretion of hormones from other endocrine glands in the body. The thyroid gland produces hormones that regulate metabolism and calcium levels in the body. The parathyroid glands work in conjunction with the thyroid gland to regulate calcium levels. The adrenal glands produce hormones that regulate stress responses and energy metabolism. The pancreas produces hormones that regulate blood sugar levels. The gonads produce sex hormones that regulate sexual development and reproductive function.

Hormones are transported throughout the body by the circulatory system and interact with specific target cells to produce a response. The endocrine system works in coordination with the nervous system to maintain homeostasis and respond to changes in the environment.

Disorders of the endocrine system can lead to hormonal imbalances and a range of health issues such as diabetes, thyroid disorders, infertility, and growth disorders. Treatment may involve medication, hormone replacement therapy, or surgical intervention.