Anterior pituitary gland in easy language

so as we know the pituitary gland is associated with the hypothalamus in the brain and it's on a stalk the stalk sometimes called the uh infundibulum just a technical name for the pituitary stalk and here we have the uh large anterior lobe of the pituitary gland this is the front the front anterior lobe is the larger of the two loes I'm not going to draw the posterior lobe on this diagram because we're focusing on the anterior but you know it would be here uh towards the back now there's different types of tissue in the anterior pituitary that produce different endocrine products so for example this some cells called thyrotropes thyrotropes now these thyro tro cells are particular cells I've drawn them in one location here imagine these are where the thyroid tropes live in in in practice they're sort of diffused actually a bit throughout the gland but the thyrotropes like the other cells in the anterior pituitary in the adino hypo fisis are stimulated by the trophic hormones or rather by the releasing hormones by the releasing hormones produced in the hypothalamus passing down through the portal veins stimulating the release of the trophic hormones so the releasing hormones are produced in the hypothalamus and the particular releasing hormone that stimulates the thyrotropes is thyrotropin releasing hormone so so thyrotropin releasing hormone produced in the hypothalamus travels down the portal system stimulates the thyrotropes so you can kind of Imagine these thyrotropes sitting there're doing nothing until they're stimulated by the thyrotropin releasing hormone then the thyrotropes kick into interaction and what the thyro tropes do is they produce the thyroid stimulating hormone and the thyroid stimulating hormone will then go off and stimulate the thyroid gland to produce thyroid hormone now there's other cells called somat troes present in the adino hypo fisis the anterior pituitary so there's a group of cells called somat trops and again you can think of these somato tro sitting there not doing very much until they releasing hormone is produced by the hypothalamus and will stimulate them so this would be growth hormone releasing hormone growth hormone releasing hormone and that is going to stimulate the somato trops and when the somato stro somato troes s stimulated they're going to produce the growth hormone stimulates many tissues of the body to uh to grow during childhood too much will cause giantism not enough will cause dwarfism but there's also a growth hormone inhibiting hormone that's theasin sasin that will also affect the somatos but in a negative way it will inhibit them so the more growth hormone releasing hormone that effect is positive that will increase the release of growth hormone from the smat tropes but the growth hormone inhibiting hormone the somat stasis will inhibit that's a negative effect so there's other cells in the anterior pituitary called corticotropes corticotropes now the corticotropes again there're stimulated by releasing or hormone and their releasing hormone is called um corticotropin releasing hormone CR corro in releasing hormone stimulates the corticotropes and the corat trops will produce the adreno cortico Tropic hormone act everything in endocrinology seems to have initials TSH GH AC adreno corticotrophic hormone and that's going to go off to the adrenal cortex and produce adrenal cortical hormones such as cortisol so again these separate separate cells in this case the cortic tropes now there's some some other cells called gonad tropes gadat TRS again separate cells in the adino hypo fisis gadat tropes and their release is stimulated by the releasing hormone from the hypothalamus called gonadotropin releasing hormone so when the gadat tropen releasing hormone is produced by the hypothalamus that will pass down the portal system to the adino hypo fisis that is the anterior pituitary gland and that will stimulate the gonadotropes and the gonadotropes as a consequence will produce a hormone called follicle stimulating hormone follicle stimulating hormone and another hormone called lutenizing lutenizing hormone now the folicular stimulating hormone is going to stimulate the development of the ovar particularly in the first half of the menstrual cycle and the folicular stimulating hormone will also stimulate the ovaries to produce more estrogen so this is what's activated in puberty and increasing estrogen production generating female secondary sexual characteristics and the follicular stimulating hormone actually is present in men as well where it stimulates the production of sperm so it stimulates spermatogenesis in men so men and women both have follicular stimulating hormone orbe it with different roles now the lutenizing hormone lutenizing means yellowing it changes the color of the uh the follicle in the ovary and as well as that the lutenizing hormone stimulates ovulation so it stimulates the actual process of the release of the ovam from the ovary and it also regulates the level of progesterone in the second half of the menstrual cycle and in men the lutenizing hormone stimulates the cells in the testes that produce testosterone so in men it's the lutenizing hormone that stimulates the release of testosterone so again functions in males and females and the fifth type of cells in the anterior pituitary Tre in the adino hypo fisis are called lactotropes lactotropes so again a different type of cell lactotropes now the release of the hormone produced by the lactotropes is produced by uh stimulated by prola releasing hormone so that stimulates the lactotropes and from the name I think we can see that is going to stimulate the production of prolactin and prolactin the trophic hormone produced by the LA trops will stimulate milk synthesis in the process of lactation so what we see it looks complicated originally initially but what we see is that there's a whole range of releasing hormones so thyrotrophin releasing hormone growth hormone releasing hormone growth hormone inhibiting hormone corticotropin releasing hormone gonadotropin releasing hormone prolactin releasing hormone or stimulating the appropriate specialized cells it's amazing how complicated the anterior pituitary is with all these different cell types so stimulating the thyrotropes stimulating or inhibiting the somatotropes the corticotropes the gonadotropes and the lactotropes and all of these producing particular trophic hormones so on this side these are all the releasing hormones and on this side these are all the trophic hormones the trophic hormones going off performing all of these functions in the body and regulating the rest of the endocrine system so we see these levels of control the ultimate level of control the master of the endocrine Orchestra or the conducting a conductor of the endocrine Orchestra is the hypothalamus but it's doing so via regulating the release of these trophic hormones

Channel: Dr. John Campbell

Views: 45,962

Keywords: trophic hormones, anterior pituitary, adenohypophysis, endocrines, endocrine system

Id: 7p7N52YGIb8

Length: 13min 16sec (796 seconds)

Published: Mon Feb 15 2016