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The following is a list of hormones found in Humans. Spelling is not uniform for many hormones. For example, current North American and international usage uses [citation needed] estrogen and gonadotropin, while British usage retains the Greek digraph in oestrogen and favours the earlier spelling gonadotrophin.
A hormone (from the Greek participle ὁρμῶν, "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physiology and behavior. [1] Hormones are required for the correct development of animals, plants and fungi. Due to the broad ...
The pituitary gland (or hypophysis) is an endocrine gland about the size of a pea and weighing 0.5 grams (0.018 oz) in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain, and rests in a small, bony cavity (sella turcica) covered by a dural fold (diaphragma sellae).
Signaling molecules binding surface receptors are generally large and hydrophilic (e.g. TRH, Vasopressin, Acetylcholine), while those entering the cell are generally small and hydrophobic (e.g. glucocorticoids, thyroid hormones, cholecalciferol, retinoic acid), but important exceptions to both are numerous, and the same molecule can act both ...
In order for steroid hormones to cross the lipid bilayer of cells, they must overcome energetic barriers that would prevent their entering or exiting the membrane. Gibbs free energy is an important concept here. These hormones, which are all derived from cholesterol, have hydrophilic functional groups at either end and hydrophobic carbon backbones.
Cortisol is a steroid hormone in the glucocorticoid class of hormones and a stress hormone. When used as medication, it is known as hydrocortisone. It is produced in many animals, mainly by the zona fasciculata of the adrenal cortex in an adrenal gland. [1] In other tissues, it is produced in lower quantities. [2]
Because peptide hormones and neurotransmitters typically are biochemically hydrophilic molecules, these first messengers may not physically cross the phospholipid bilayer to initiate changes within the cell directly—unlike steroid hormones, which usually do. This functional limitation requires the cell to have signal transduction mechanisms ...
Hormones can be amino acid complexes, steroids, eicosanoids, leukotrienes, or prostaglandins. [3] The endocrine system is contrasted both to exocrine glands, which secrete hormones to the outside of the body, and to the system known as paracrine signalling between cells over a relatively short distance.