Hormones, Endocrinology Part A

Hormone

Produced by endocrine glands, acts on cells or tissues or organs, facilitates/inhibits a physiologic process

Endocrine Gland

secretes within the body, usually into blood or lymph

Exocrine Gland

secretes externally, has ducts to carry molecules to the exterior(sweat, urine, mucous, ect)

hormones integrate body functions

neural(seconds), endocrine(minutes to hours), neuro-endocrine system

Examples of hormones regulating body functions

growth(growth hormone), lactation(oxytocin), estrous cycle(estradiol), ovulation(leuteinizing hormone), parturition(oxytocin, relaxin)

“types” of hormones

site of production, stimulatory or inhibitory, structure(protein or lipid, large or small)

Hypothalamus(master neuroendocrine gland)

appetite, thirst, body temp, vasomotor activity, emotion, use of body nutrient reserves, activity of intestine, sleep, sexual behavior, production and secretion of reproduction releasing hormones

hypothalamic hormones

stimulatory/inhibitory(gonadotropin releasing hormone(GnRH)(stimulatory), growth inhibitory hormone(stomatostatin)(inhibitory)), structure and size(short chain polypeptides(3-44aa), 1000-2000 MW)

Releasing hormones of the hypothalamus

Gonadotropin releasing hormone(GnRH)(stimulate leuteinizing hormone(LH), and follicle stimulating hormone(FSH) release), thyrotrophin releasing hormone(TRH)(stimulate thyroid stimulating hormone(TSH) and prolactin release), corticotrophin releasing hormone(CRH)(stimulate ACTH release), growth hormone releasing hormone(GH-RH)(stimulate growth hormone(GH) release), somatostatin(growth hormone inhibiting hormone)(inhibits growth hormone release)