Simple Pharmanotes

  Introduction. The menstrual cycle is the process of discharge of blood and broken tissues from the vagina of a woman every month from puberty to menopause except during pregnancy and some months of breastfeeding .  It is a periodical proces s that produces changes in the female reproductive system which is responsible for the pregnancy. The first onset of the menstruation cycle is called “ Menarche ”. The permanent stoppage of the menstruation cycle is called “ Menopause ”. Various hormones play important roles during the 28 days cycle . For easy understanding the menstruation cycle is divided into two, Ovarian cycle . Uterine cycle . Hormones in the Menstrual Cycle. The hypothalamus releases a hormone called “ Gonadotropin Releasing Hormone ( GnRH )”. The Gonadotropin Releasing Hormone acts on the anterior lobe of the pituitary gland to secrete two gonadotropins as, Follicle Stimulating Hormone ( FSH ) (Required for  the maturation of ovarian follicles and also

  Introduction. The process of formation of gametes is called gametogenesis . The male gametogenesis is called “ Spermatogenesis ”. The female gametogenesis is called “ Oogenesis ”. Oogenesis takes place in the following stages, Prenatal Stage . Antral Stage . Pre ovul a tory Stage . Prenatal Stage: Unlike male spermatogenesis which starts after puberty, the process of oogenesis starts in the embryonic stage only. The stem cells called Primordial cells divide mitotically and produce Primary oocytes which start Meiosis but get arrested in the Prophase-I only . These primary oo c ytes get covered by follicular cells of ovary called granulosa cells , which secrete a glycoprotein layer around the primary oocyte, the layer is called “ Zona pellucida ”. Antral Stage: The fluid-filled gap between granulosa cells combines to produce the antrum , a central fluid-filled region.  Now the primary follicles are called “ Secondary Follicl e s”.  These secondary follicles start furth