BSC 2086 01 Anatomy and Physiology II Spring 2013 22 The Reproductive System Part 2 2012 Pearson Education Inc An Introduction to the Reproductive System Learning Outcomes 28 3 Describe the components of the female reproductive system and the ovarian roles in oogenesis explain the complete ovarian and uterine cycles outline the histology anatomy and functions of the vagina and summarize all aspects of the female reproductive cycle 2012 Pearson Education Inc 28 3 The Female Reproductive System The Female Reproductive System Produces sex hormones and functional gametes Protects and supports developing embryo Nourishes newborn infant 2012 Pearson Education Inc 28 1 Structures of the Reproductive System The Female Reproductive System Ovaries or female gonads Release one immature gamete oocyte per month Produce hormones Uterine Fallopian tubes oviducts Carry oocytes to uterus if sperm reaches oocyte fertilization is initiated and oocyte matures into ovum Uterus Vagina Encloses and supports developing embryo Connects uterus with exterior 2012 Pearson Education Inc Figure 28 13 The Female Reproductive System Ovarian follicle Ovary Uterine tube Vesicouterine pouch Urinary bladder Pubic symphysis Urethra Paraurethral glands Greater vestibular gland Clitoris Labium minus Labium majus 2012 Pearson Education Inc Figure 28 14a The Ovaries and Their Relationships to the Uterine Tube and Uterus Ovarian artery and vein Fimbriae Uterine tube Ovarian ligament Suspensory ligament Infundibulum Ovary Uterus Ureter Uterosacral ligament External os Cervix Vaginal rugae Vaginal wall 2012 Pearson Education Inc A posterior view of the uterus uterine tubes and ovaries 28 3 The Female Reproductive System Ovaries small almond shaped organs near lateral walls of pelvic cavity Three main functions 1 Production of immature female gametes oocytes 2 Secretion of female sex hormones estrogens progestins 3 Secretion of inhibin involved in feedback control of FSH released from anterior pituitary 2012 Pearson Education Inc 28 3 The Female Reproductive System Oogenesis Also called ovum production Begins before birth oogonium completes mitotic division to produce primary oocyte Primary oocyte development halts at prophase of meiosis I until puberty Accelerates at puberty some primordial follicles each containing a primary oocyte will become activated each month one will release a secondary oocyte ovulation the other activated follicles will degenerate atresia Ends at menopause 2012 Pearson Education Inc Figure 28 15 Oogenesis Oogenesis Mitosis of oogonium Unlike spermatogonia the oogonia o o GO ne uh or female reproductive stem cells complete their mitotic divisions before birth Oogonium Meiosis I Between the third and seventh months of fetal develop ment the daughter cells or primary oocytes O o s ts prepare to undergo meiosis They proceed as far as the prophase of meiosis I but then the process comes to a halt Tetrad The primary oocytes remain in a state of suspended development until the individual reaches puberty when rising levels of FSH trigger the start of the ovarian cycle Each month after the ovarian cycle begins some of the primary oocytes are stimulated to undergo further development Meiosis I is then completed yielding a secondary oocyte and a polar body First polar body First polar body may not complete meiosis II Meiosis II Each month after the ovarian cycle begins one or more secondary oocytes leave the ovary suspended in metaphase of meiosis II Meiosis II will be completed only if fertilization occurs Oogonium Primary oocyte diploid Primary oocyte DNA replication Secondary oocyte diploid Secondary oocyte released in metaphase of meiosis II The polar body produced in meiosis I may or may not undergo meiosis II in either case the polar bodies soon degenerate Second polar body Mature Ovum upon fertilization 2012 Pearson Education Inc 28 3 The Female Reproductive System Process of Oogenesis Primary oocytes remain in suspended development until puberty At puberty Rising FSH triggers start of ovarian cycle Each month thereafter Some primary oocytes are stimulated to develop further 2012 Pearson Education Inc 28 3 The Female Reproductive System Differences between Oogenesis and Spermatogenesis 1 Cytoplasm of primary oocyte divides unevenly Producing one secondary oocyte with original cytoplasm And two or three smaller polar bodies that disintegrate 1 Ovary releases secondary oocyte not mature ovum Suspended in metaphase of meiosis II Meiosis is completed upon fertilization by one sperm cell Polyspermy fertilization of one secondary oocyte by more than one sperm cells is prevented 2012 Pearson Education Inc 28 3 The Female Reproductive System The Ovarian Cycle After sexual maturation puberty A different group of primordial follicles is activated each month One of the primordial follicles will develop into a tertiary follicle and release a secondary oocyte ovulation The other activated follicles will degenerate Is divided into Follicular phase preovulatory phase Luteal phase postovulatory phase 2012 Pearson Education Inc 28 3 The Female Reproductive System Follicular Phase initiated by FSH from ant pit Ovarian Follicles specialized structures in cortex of ovaries where oocyte growth and meiosis I occur Primordial Follicle primary oocyte surrounded by follicle cells Primary follicle activated primordial follicles Follicle cells divide become granulosa cells produce estrogens Secondary follicle few of the primary follicles mature into this Inner follicular cells secrete follicular fluid separates inner and outer follicle layer Tertiary mature graafian follicle usually 1 2 secondary follicles develops this each month Primary oocyte continues from prophase I produces secondary oocyte that stops at metaphase II 2012 Pearson Education Inc Figure 28 16 The Ovarian Cycle Step 5 Primary follicle Primordial follicles Secondary follicle Tertiary follicle Corpus albicans Corona radiata Corpus luteum Released secondary oocyte Ovulation Follicular fluid Secondary oocyte within corona radiata Ruptured follicle wall Outer surface of ovary 2012 Pearson Education Inc Figure 28 16 The Ovarian Cycle Step 1 Primordial follicles in egg nest Formation of primary follicle Granulosa cells Primary oocytes Zona pellucida Thecal cells LM 1440 LM 1092 Primary oocyte Follicle cells 2012 Pearson Education Inc Figure 28 16 The Ovarian Cycle Step 3 Formation of secondary follicle Formation of tertiary follicle Antrum containing follicular
View Full Document
Unlocking...