My teacher says that all organs of our body secrete some kind of hormone so they are all glands. Is the statement entirely correct without any exceptions? Till date I am unable to find any exception for that statement. Could anybody provide an exception if any present?

  • 2
    $\begingroup$ Oesophagus is one such e.g that comes to mind $\endgroup$
    – Tyto alba
    Mar 9, 2017 at 13:46
  • 6
    $\begingroup$ Oesophagus contain adipose tissue which secretes hormones like leptin, adiponectin and resisting. $\endgroup$
    – JM97
    Mar 9, 2017 at 14:04
  • 3
    $\begingroup$ How do you define an organ? Paracrine signalling factors are not considered hormones. If you consider interferons and chemokines as hormones, then cells that secrete these are found almost everywhere. $\endgroup$
    Mar 10, 2017 at 5:22

1 Answer 1


Good question! The major and most common endocrine glands in the human body include pituitary, thyroid, parathyroid, thymus, adrenal, pancreas, gonads and pineal gland, along with neuroendocrinol glands like hypothalamus. Some other, not-so-common, examples include heart (Anti-Natriuretic Factor), GI tract organs (gastrin, secretin, etc.), placenta (estrogen, progesterone, etc.), kidneys (erythropoietin, renin), skin (cholecalciferol) and adipose tissue (leptin)1. Even the lungs are known to secrete calcitonin2.

In spite of this, I can think of quite a few examples of organs which do not act as endocrine glands. That is because there is a difference between the organs secreting hormones and endocrine glands. The definition of endocrine glands is as follows1, 5, 6, 7, 8:

Endocrine glands are glands of the endocrine system that secrete their products, hormones, directly into the blood rather than through a duct.

So, if these organs don't directly secrete the hormones into the bloodstream, then they are not endocrine glands. Leading this way, emotional tears are known to consist of hormones such as prolactin, ACTH and leucine-enkephalin3, 4. Thus, though eyes do secrete hormones, they are not endocrine glands. Also, not sure about this, but lungs still do not seem to fit in the category of endocrine glands.

In short, all the organs of the body might secreted hormones, but they all cannot be considered as endocrine glands.


  1. Endocrine gland - Wikipedia

  2. [Hormone expression and opioid receptors in fetal and adult lung] Gómez-Román JJ, Cifrián Martínez JM, Fernández Rozas S, Fernando Val-Bernal J.

  3. Frey W. H., DeSota-Johnson D., Hoffman C., McCall J. T. (1981). Effect of stimulus on the chemical composition of human tears. Am. J. Ophthalmol. 92 559–567. 10.1016/0002-9394(81)90651-6

  4. What biological functions does crying serve? - Biology Stack Exchange

  • $\begingroup$ Mesentery too contains adipocytes implying that these adipocytes too secrete leptin and other hormones, thanks for efforts. $\endgroup$
    – JM97
    Mar 9, 2017 at 14:19
  • $\begingroup$ It would be much better to add definition from a authority holding site, Wikipedia page there does not cite any source either. $\endgroup$
    – JM97
    Mar 9, 2017 at 14:25

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