Endocrine system

The endocrine system includes those organs of the body which produce hormones. It helps to regulate metabolism, growth and development, tissue function, and plays a part also in mood.[1] The field of medicine that deals with disorders of endocrine glands is endocrinology.

In physiology, the endocrine system is a system of glands, each of which secretes a type of hormone directly into the bloodstream to regulate the body.

The endocrine system is in contrast to the exocrine system, which secretes its chemicals using ducts.[2] The endocrine system is an information signal system like the nervous system, yet its effects and mechanism are different.

The endocrine system's effects are slow to start, and long-lasting in their response. The nervous system sends information quickly, and responses are generally short lived. Hormones are complex chemicals released from endocrine tissue into the bloodstream where they travel to target tissues and trigger a response.

Features of endocrine glands are, in general, they have no ducts, they have a good blood supply, and usually they have vacuoles or granules inside their cells, storing their hormones.

Major endocrine glands. (Male left, female on the right.) 1. Pineal gland 2. Pituitary gland 3. Thyroid gland 4. Thymus 5. Adrenal gland 6. Pancreas 7. Ovary 8. Testes

Endocrine glands and the hormones they secrete

Central nervous system

Endocrine glands in the human head and neck and their hormones
  • Hypothalamus produces
    • Thyrotropin-releasing hormone (TRH) Parvocellular neurosecretory neurons
    • Gonadotropin-releasing hormone (GnRH) Neuroendocine cells of the Preoptic area
    • Growth hormone-releasing hormone (GHRH) Neuroendocrine neurons of the Arcuate nucleus
    • Corticotropin-releasing hormone (CRH) Parvocellular neurosecretory neurons
    • Vasopressin Parvocellular neurosecretory neurons
    • Somatostatin (SS; also GHIH, growth hormone-inhibiting hormone) Neuroendocrince cells of the Periventricular nucleus
    • Prolactin inhibiting hormone or PIH or Dopamine (DA) Dopamine neurons of the arcuate nucleus
    • Prolactin releasing hormone
  • Pineal body produces
  • Pituitary gland (hypophysis) produces
    • Anterior pituitary lobe (adenohypophysis)
    • Posterior pituitary lobe (neurohypophysis)
      • Oxytocin Magnocellular neurosecretory cells
      • Vasopressin (AVP; also ADH, antidiuretic hormone) Magnocellular neurosecretory cells
    • Intermediate pituitary lobe (pars intermedia)
      • Melanocyte-stimulating hormone (MSH) Melanotroph

Thyroid

  • Thyroid produces
    • Triiodothyronine (T3), the potent form of thyroid hormone Thyroid epithelial cell
    • Thyroxine (T4), also known as tetraiodothyronine: it is a less active form of thyroid hormone (mainly) Thyroid epithelial cells
    • Calcitonin Parafollicular cells

Parathyroid

  • Parathyroid hormone PTH triggers an increase in blood calcium levels.

Muscles

  • Striated muscle produces

Alimentary system

  • Stomach produces
    • Gastrin (mainly) G cells
    • Ghrelin P/D1 cells
    • Neuropeptide Y (NPY)
    • Secretin S cells
    • Somatostatin D cells
    • Histamine ECL cells
    • Endothelin X cells
  • Duodenum produces
    • Cholecystokinin I cells
  • Liver produces
    • Insulin-like growth factor (IGF) (mainly) Hepatocytes
    • Angiotensinogen Hepatocytes
    • Thrombopoietin Hepatocytes
  • Pancreas produces
    • Insulin (mainly) β Islet cells
    • Glucagon (also mainly) α Islet cells
    • Somatostatin δ Islet cells
    • Pancreatic polypeptide PP cells

Kidney

  • Kidney produces
    • Renin (Primarily) Juxtaglomerular cells
    • Erythropoietin (EPO) Extraglomerular mesangial cells
    • Calcitriol (the active form of vitamin D3)
    • Thrombopoietin

Adrenal glands

Reproductive system

Male

Female

Calcium regulation

Miscellaneous

References

  1. ↑ Collier Judith; et al. (2006). Oxford Handbook of Clinical Specialties 7th edn. Oxford University Press. pp. 350 -351. ISBN 0-19-853085-4.
  2. ↑ It derives from the Greek words endo meaning inside, within, and crinis for secrete.

Other websites


Endocrine system
Adrenal gland - Corpus luteum - Hypothalamus - Ovaries - Pancreas - Parathyroid gland - Pineal gland - Pituitary gland - Testes - Thyroid gland - Hormone