Female Reproductive System - Part 1 PDF

Female reproductive system Part 1 Female reproductive system Female reproductive system Function: Production of female gametes (ova) by oogenesis Reception of male gametes (spermatozoa) Provide a suitable environment or fertilization of ova by sperm Provide an environment for fetal development A mea...

Female reproductive system Part 1 Female reproductive system Female reproductive system Function: Production of female gametes (ova) by oogenesis Reception of male gametes (spermatozoa) Provide a suitable environment or fertilization of ova by sperm Provide an environment for fetal development A means for the expulsion of development fetus to external environment Nutrition of newborn Female reproductive system Female reproductive system is divided to: The ovaries The genital tract and breast Female reproductive system The ovaries : Paired organs lying in the pelvic cavity , are the sites of oogenesis Ova are released by process of ovulation in cyclical manner The cyclical ovulation suspended during pregnancy. The process of ovulation is controlled by cyclical release of gonado–trophic hormones from anterior pituitary. Ovaries have an endocrine function by secretion of estrogen and progesterone Ovaries are flattened , oval organs encapsulated in a fibrous connective tissue layer called tunica albuginea (named for its white appearance grossly) Female reproductive system Follicular development : Female reproductive system Follicular development : Female reproductive system Follicular development : Female reproductive system Follicular development : Primordial follicle : which composed of a primary oocytes surrounded by a single layer of flattened follicular cells Primary follicle : in primary follicle oocyte enlarges and follicular cells become cuboidal , a homogenous glycoprotein layer (Zona pellucida) develops between oocyte and follicular cells The surrounding C.T stroma formed organized layer a round follicle called theca folliculi which is later developed and differentiate into 2 layers, theca interna and theca externa Follicular cells a round oocyte developed and proliferate to form zona granulosa Female reproductive system Secondary follicle: Secondary follicle : zona granulosa proliferated and a space called follicular antrum appears in which follicular fluid accumulates (at this stage oocyte reached its mature size and situated in a thickened area of the granulosa called cumulus oophorus Theca interna and externa well developed the cisternae secrete oestrogen hormones, which promote proliferation of uterine mucosa to be ready for fertilized ovum implantation Theca externa composed of C.T. and has no endocrine function. Female reproductive system Graffian follicle : Female reproductive system Graffian follicle : At this stage oocyte become known as secondary oocyte and 1st meiotic division complete just before ovulation. The follicular antrum enlarged, and zona granulosa form a layer around periphery of follicle Leaving oocyte to surround by a layer of several cell called corona radiata At ovulation mature follicle ruptures and ovum comprising secondary oocyte Zona pellucida and corona radiate is expelled into peritoneal cavity near the entrance of uterine tube The second meiotic division of oocyte is not completed until after penetration of ovum by spermatozoon. Female reproductive system Corpus luteum: Female reproductive system Corpus luteum: Following ovulation the ruptured follicle collapsed and fills with blood clot and 3 layer of follicular wall become re-organized to form temporary endocrine gland (the corpus luteum ) Under the effect of LH (luteinizing hormone) secreted by granulosa increase in size and begin secretion of progesterone hormone The cytoplasm of theses cells contains a bright yellow pigment which give rise to granulosa luteal cells The cells of theca interna increase and become known as theca luteal cells (para luteal cells) Female reproductive system Corpus luteum: The blood clot , theca luteal and granulosa luted layers are invaded by capillaries from theca externa to form rich vascular network The corpus luteum is dependent on the secretion of LH hormone from the anterior pituitary increase levels of progesterone Inhibit LH secretion and without stimulus of LH, corpus luteum (CL) can’t be maintained and 12-14 days after ovulation it regresses to form functionless corpus albicans When CL regress the secretion of estrogen and progesterone. Ceases and so mucosal lining of uterus collapse with onset of menstruation Female reproductive system Corpus luteum: Implantation of a fertilized ovum in uterine wall interrupts the integrated ovarian and menstrual cycles After implantation a hormone called human chorionic gonadotrophin (HCG) is secreted into the maternal circulation by the developing placenta. HCG has an analogous function to LH maintaining the function of corpus luteum in secreting estrogen and progesterone until about 12 weeks of pregnancy after that CL of pregnancy slowly regress to form functionless C.albicans and placenta takes over the major role of estrogen and progesterone secretion till parturition Female reproductive system Corpus albicans : Female reproductive system Corpus albicans : Is the inactive fibrous tissue mass which forms following the involution of corpus luteum Secretory cells of degenerate CL autolyze and a re-phagocytised by macrophage. The vascular supporting tissue regress to form a cellular scar which merges with surrounding ovarian Female reproductive system Atretic follicle : The follicular atresia (degeneration) may occur at any stage in the development of ovum. The histological appearance varies depend on stage of development reached and progress of atresia. In advanced atresia there is thickening of basement membrane between granulosa cells and theca interna forming the so called glassy membrane Atretic follicles are replaced by fibrous CT