The sensitivity of the uterine musculature is :
Ans. is d i.e. Enhanced by oestrogsn and inhibited by progesterone Estrogens : The main and most powerful estrogen produced by the ovary is oestradiola, followed by less active oestrone. Many metabolites of the estrogen are produced by liver, amongst which most impoant is oestriol.o Chief oestrogen in the reproductive year : Oestradiolo Main oestrogen in menopause : oestroneo Main oestrogen in pregnancy : oestriolo Estrogen receptors ER - a ER-ss Predominant sub-type in uterusdeg Predominant subtype in ovary, testis, prostate, brain, blood vessels, bone Main action of estrogen is on Secondary sexual characteristics Genital tract It determines feminine sensitivity and shyness Has main role in breast development Mainly uterus (see below) Progesterone : lt is secreted mainly by the corpus luteumo (i.e. secreted mainly after ovulation). The preovulatory rise in the progesterone is because luteinizing hormone initiates luteinization and progesterone production by the granulosa layer. Main action of progesterone is maintenance of pregnancyo and its action on uterus are inclined in this direction' Effect of estrogen and progesterone on uterus : Effect of estrogen Eflect of progesterone Estrogen causes marked proliferation of the endometrial stroma and greatly increased development of the endometrial glandso that will later be imPlanting ovum. Promote secretory changes in the ulreine endometrium during the later half of the monthly female sexual cycle, thus prepares the uterus for implanatation of the feilized ovum. Estrogen causes hyperophy of the myo metrium.o Progesterone causes marked swelling and secretory development of the endometrium Estrogen stimulates the synthesis of myometrial contractile protein actinomybin through aAMP. lJnder the influence of estrogens the muscles beile more active and excitable and action potentials in the individual fibres become more frequent.o lt aids estrogen in myometrial hyperophy Glands increase in touosity and excess of secretory substance is accumulated in glandular epithelial cells. Lipid and glycogen deposits also increase' The estrogen dominated uterus is also more sensitive to oxytocin. In addition to the secretory effect on endometrium, prrysterone decreases the frequency and intensity of utrine contractions, thereby helping to prevent expulsion of the implanted ovum but increases the amplitude of contraction.
Enhanced by progesterone
Enhanced by oestrogen
Inhibiled by oestrogen
Enhanced by oestrogsn and inhibited by progesterone