Anatomy and Physiology Biology 2401 Chapter-28 The Female Reproductive System

Female Reproductive System Made of: Ovaries – to produce oocytes (eggs) and hormones Uterine tubes – to transport oocyte and early embryo Uterus – supports embryo development Vagina – to receive sperms and deliver newborn Mammary glands – to nourish the newborn

Female Reproductive System Support for the reproductive organs: Broad ligament - attaches uterus to the wall of pelvis Ovarian ligament - anchors ovary to uterus Suspensory ligament - supports blood vessels to ovaries

Figure 28-18b The Uterus POSTERIOR Sigmoid colon Broad ligament Suspensory ligament of ovary Uterosacral ligament Uterine tube Cardinal ligaments (under broad ligament) Ovarian ligament Uterus Ovary Round ligament of uterus Urinary bladder ANTERIOR A superior view of the ligaments that stabilize the position of the uterus in the pelvic cavity 4

Female Reproductive System - - Ovaries Pair of oval organs Descend into the pelvic region during the 3rd month of fetal development Hilum - depression on one side where blood vessels enter/exit Made of: - germinal epithelium that covers the surface of the ovaries - ovarian cortex that contains different stages of follicular development - ovarian medulla is the central part of the ovary that has blood vessels

Female Reproductive System - Oogenesis Formation of an egg/ovum Process begins in the fetus  continues after puberty Starts with a diploid oogonium (44XX)  divides by mitosis to form diploid primary oocytes (44XX)  primary oocyte divides by meiosis I to form 2 haploid cells (22X): : secondary oocyte : first polar body (non-functional cell)  secondary oocyte is released during ovulation  after syngamy (fusion with sperm), sec. oocyte undergoes meiosis II to form: : a functional ovum : second polar body 44XX 44XX 22X 22X 22X 22X 22X 22X

Female Reproductive System - Follicular Development In 3 months fetus: Oogonia divide by mitosis  form diploid primary oocyte surrounded by 1 layer of flat follicular/granulosa cells – primordial follicle  primary oocytes begin meiosis I but stop at prophase I At birth, about 2,000,000 primordial follicles are formed in the ovary

Female Reproductive System - Follicular Development During early childhood years, the number of primordial follicles is reduced to about 200,000 In a few primordial follicles, the number of follicular layers increases  primordial follicles increase in size  become primary follicles (primary oocyte at prophase I + 1-7 layers of follicular cells)  some primary follicles continue to grow  become secondary follicles (with multiple layers of follicular cells)  a glycoprotein layer – zona pellucida develops around primary oocyte  follicular cells secrete fluid in the center of the follicle – follicular cavity (antrum) develops in the secondary follicle

Female Reproductive System - Follicular Development Each month after puberty  one secondary follicle matures to form a Graafian follicle  Graafian follicle secretes hormones  Graafian follicle bursts - ovulation  secondary oocyte (surrounded by zona pellucida and corona radiata - layers of follicular cells) is released  follicular jacket remains in the ovaries and continues to secrete hormones to support early pregnancy – becomes corpus luteum  eventually, it degenerates – corpus albicans

Female Reproductive System Uterine tube Ovulation  secondary oocyte is released by the ovaries  it enters the infundibulum of the uterine tube with the help of fimbriae Functions: Site for fertilization Early embryo development Transportation of the embryo to the uterus Wall histology: Mucosa – ciliated, simple columnar epithelium Muscularis – circular and longitudinal smooth muscles (peristalsis) Serosa – serous membrane

Female Reproductive System Uterus Consists of fundus, body and cervix Wall of the uterus: Endometrium – inner layer; shed during menstruation; embryo implantation Myometrium – middle smooth muscle layer; contraction  delivery Perimetrium – outer serosa layer Cervix: opens into the vagina : secretes mucus to plug the opening during pregnancy

Female Reproductive System Vagina Passageway for sperms Birthing canal Passageway for menstrual flow Wall has folds (rugae) and lined by stratified squamous epithelium

Female Reproductive System - Hormonal Control

Female Reproductive System – The Cycle Female reproductive cycle: monthly changes (28 days) in the female reproductive structures and hormones Ovarian cycle: monthly changes in the ovaries Menstrual cycle: monthly changes in the uterus Phases of reproductive cycle: Preovulatory phase – lasts 6-13 days - follicles develop in the ovaries  ends with ovulation - endometrial wall develops in the uterus Postovulatory phase – lasts about 14 days - formation of corpus luteum - surge in ovarian hormones - increased secretion of the uterine glands in the cervix A. If secondary oocyte is fertilized  pregnancy B. If secondary oocyte is not fertilized Menstrual phase – lasts about 4-5 days - secondary oocyte degenerates - corpus luteum degenerates - endometrium breaks down  menstruation occurs

Female Reproductive System - Hormonal Control

Female Reproductive System Modified sweat glands  produce milk (lactation) Size of the breast – determined by the amount of the adipose tissue Mammary ducts bring the milk to the nipple Hormonal regulation: Estrogen – for the development of the breast Prolactin – making of milk Oxytocin – release of milk

Female Reproductive System – Puberty and Menopause Puberty: - Starts at age 7 or 8 years - A surge of adrenal androgens (adrenarche)  growth of pubic and axillary hair - Sleep associated increases in GnRH, LH, FSH  stimulate ovaries (primary follicles transform to secondary follicles)  development of secondary female characteristics (breast, figure)  first menses (menarche)….age 12  first ovulation – about 6-9 months later Menopause: - Last menses - Starts around age of 40-50 years - Due to decrease in LH and FSH receptors in the ovaries  follicular development stops  decrease in ovarian hormones (estrogens, progesterone)  infrequent menses  hot flashes, headaches, hair loss, weight gain, emotional instability, insomnia, muscular pain

Female Reproductive System – Disorders Amenorrhea: absence of menstruation Menstrual cramps: breakdown of endometrium  inflammatory process  prostaglandin production  affects smooth muscle contraction in uterus  cramps Premenstrual syndrome (PMS): hormonal changes  changes in mood Toxic shock syndrome (TSS): Staphylococcus infection Sexually transmitted diseases (STD): bacterial or viral infections of the reproductive tract  may result in cancer Endometriosis: proliferation of the endometrial cells to other abdominal organs  respond to hormones  cause frequent inflammation Breast cancer: risk factors (family history, radiation exposure, smoking, alcohol intake, excessive fat, genetic); detected through mammogram, ultrasound and CT scan; treated with surgery (lumpectomy or mastectomy), chemotherapy, radiation therapy Fibrocystic breast: benign changes in the breast – cysts, increased connective tissue, or hyperplasia of the ducts Cervical cancer: due to viral infection or genetic disposition : detected by Pap smear (removal of a sample of cervical cells exam) Hysterectomy: surgical removal of uterus (or complete reproductive system)

Sterilization Procedures Male Sterility: Vasectomy - Vas deferens is cut, folded back and tied  sperm passage is blocked  testes continue to produce sperms and testosterone (although the levels may decrease)  sperms disintegrate No major effect on the physiology in most cases Female Sterility: Tubal ligation – Oviduct is cut, folded back and tied  access to secondary oocyte is blocked for the sperms  ovaries continue to develop follicles and hormones  secondary oocytes degenerate in the oviduct No major effect on the physiology