Endocrine system
Hormonal messenger system regulating distant organs via feedback loops.
The endocrine system is a messenger system in an organism comprising feedback loops of hormones that are released by internal glands directly into the circulatory system and that target and regulate distant organs. In vertebrates, the hypothalamus is the neural control center for all endocrine systems. The study of the endocrine system and its disorders is known as endocrinology, a branch of internal medicine.
- field
- Endocrinology
- known_for
- Regulating distant organs via hormone feedback loops
- major_glands
- Thyroid, parathyroid, pituitary, pineal, adrenal, testis, ovaries, hypothalamus, pancreas, thymus
- key_hormones
- Thyroxine, growth hormone, melatonin, testosterone, estrogen, progesterone, insulin, glucagon
- contrast
- Endocrine glands have no ducts; exocrine glands have ducts
Lore & Background
The endocrine system consists of several systems that operate via feedback loops, mediated largely through the hypothalamus and pituitary. The hypothalamus is a key regulator of the autonomic nervous system and links the endocrine system to the nervous system via the pituitary gland. The pituitary gland has two parts: the anterior pituitary produces tropic hormones such as TSH, ACTH, GH, LH, and FSH; the posterior pituitary stores and secretes antidiuretic hormone and oxytocin, synthesized in the hypothalamus.
Reader's Guide
The endocrine system is fundamental to homeostasis, controlling metabolism, growth, reproduction, and stress responses through hormone signaling. Its major glands include the thyroid, parathyroid, pituitary, pineal, adrenal, and gonads, as well as organs like the pancreas and hypothalamus that have secondary endocrine functions. Hormones can be amino acid complexes, steroids, eicosanoids, leukotrienes, or prostaglandins. The system operates via axes such as the hypothalamic–pituitary–adrenal axis. Understanding the endocrine system is essential for diagnosing and treating disorders like diabetes, thyroid disease, and hormonal imbalances, making endocrinology a critical branch of internal medicine.
Did You Know?
- The hypothalamus is the neural control center for all endocrine systems in vertebrates.
- The pineal gland produces melatonin.
- The kidney secretes the endocrine hormone erythropoietin.
- The fetal endocrine system is one of the first systems to develop during prenatal development.
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