Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Female Reproductive Anatomy  Ovaries are the primary female reproductive organs  Make female gametes (ova)  Secrete female sex hormones (estrogen and progesterone)  Accessory ducts include uterine tubes, uterus, and vagina  Internal genitalia – ovaries and the internal ducts  External genitalia – external sex organs

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Uterus  Hollow, thick-walled organ located in the pelvis anterior to the rectum and posterosuperior to the bladder  Body – major portion of the uterus  Fundus – rounded region superior to the entrance of the uterine tubes  Cervix – narrow neck which projects into the vagina inferiorly  Cervical canal – cavity of the cervix that communicates with:  The vagina via the external os  The uterine body via the internal os

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Uterine Wall  Composed of three layers  Perimetrium – outermost serous layer; the visceral peritoneum  Myometrium – middle layer; smooth muscle  Endometrium – mucosal lining of the uterine cavity

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Endometrium  Has numerous uterine glands that change in length as the endometrial thickness changes  Stratum functionalis:  Undergoes cyclic changes in response to ovarian hormones  Is shed during menstruation  Stratum basalis:  Forms a new functionalis after menstruation ends  Does not respond to ovarian hormones

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Uterine Tubes (Fallopian Tubes) and Oviducts  Receive the ovulated oocyte and provide a site for fertilization  Empty into the uterus via the isthmus  Expand distally around the ovary forming the ampulla  The ampulla ends in the funnel-shaped, ciliated infundibulum containing fingerlike projections called fimbriae  The uterine tubes have no contact with the ovaries  Beating cilia on the fimbriae create currents to carry the oocyte into the uterine tube  The oocyte is carried toward the uterus by peristalsis and ciliary action

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  Uterine tubes (Fallopian tubes or oviducts)  Infundibulum  End closest to the ovary with numerous fimbriae  Ampulla  The middle portion, widest and longest portion  Isthmus  A short segment connected to the uterine wall  The mucosa of the uterine tube has ciliated simple columnar epithelial cells that beat toward the uterus and, with the help of muscular contractions of the tube, transmit the egg in that direction.  Fertilization occurs in uterine tube (ampulla) The Uterine tubes

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings External Genitalia  Mons pubis – round, fatty area overlying the pubic symphysis  Labia majora – elongated, hair-covered, fatty skin folds homologous to the male scrotum  Labia minora – hair-free skin folds lying within the labia majora  Clitoris  Erectile tissue homologous to the penis  Greater vestibular glands  Pea-size glands close to the vagina  Homologous to the bulbourethral glands  Keep the vestibule moist and lubricated

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Mammary Glands  Pectoral fat pad  Modified sweat glands consisting of lobes that radiate around and open at the nipple  Areola – pigmented skin surrounding the nipple  Lobes contain glandular alveoli that produce milk in lactating women  alveolar glands pass milk to lactiferous ducts, which open to the outside

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Mammary Glands  nonlactating breast consists mostly of adipose and collagenous tissue and contains very little mammary gland.  Lactating  develops during pregnancy,  it exhibits 15–20 lobes arranged around the nipple, each drained by a lactiferous duct. These dilate to form a lactiferous sinus opening into the nipple.

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Ovaries - follicles  Each follicle consists of an immature egg (oocyte)  Cells around the oocyte are called:  Follicle cells (one cell layer thick)  Granulosa and theca cells (when more than one layer is present)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Follicular development - Folliculogenesis  Primordial Follicle –flattened granulosa cell layer, basement membrane, oocyte  Primary Follicle – growth of oocyte, zona pellucida formation, cuboidal granulosa cells  Secondary Follicle – add layers of granulosa cells, formation of theca cells

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Folliculogenesis  Early Tertiary Follicle – antrum formation, zona pellucida thickens, theca interna and theca externa form, basement membrane is still present between theca and granulosa cells, blood vessels are in the theca cell layer but not in follicle  Tertiary/pre-ovulatory/Graffian – full size follicle ready to ovulate; oocyte surrounded by corona radiata (granulosa cells) and attached to follicular wall by the comulus oophorus

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  Ovum production  Occurs monthly in ovarian follicles  Part of ovarian cycle  Follicular phase (preovulatory)  Luteal phase (postovulatory) Oogenesis

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Oogenesis  Production of female sex cells by meiosis  In the fetal period, oogonia (2n ovarian stem cells) multiply by mitosis and store nutrients  Primordial follicles appear as oogonia are transformed into primary oocytes  Primary oocytes begin meiosis but stall in prophase I

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Oogenesis: Puberty  At puberty, one activated primary oocyte produces two haploid cells  The first polar body  The secondary oocyte  The secondary oocyte arrests in metaphase II and is ovulated  If fertilized, the second oocyte completes meiosis II, yielding:  One large ovum (the functional gamete)  A tiny second polar body

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Oogonia (multiple by mitosis until 5 th month of fetal development) Arrested development (until shortly before birth) Primary oocytes (arrest in prophase I) ___________________________________________________________ Puberty Oocyte in Graafian follicle – complete meiosis I Secondary oocyte first polar body Arrested in metaphase II If fertilization occur Complete meiosis II Ovum second polar body

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  Formation of primary, secondary, and tertiary follicles  Monthly series of events associated with the maturation of an egg  Follicular phase – period of follicle growth (days 1–14)  Luteal phase – period of corpus luteum activity (days 14– 28)  Ovulation occurs midcycle The ovarian cycle

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Follicular phase Luteal phase ovulation

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Luteal Phase  After ovulation, the ruptured follicle collapses, granulosa cells enlarge, and along with internal thecal cells, form the corpus luteum  The corpus luteum secretes progesterone and estrogen  If pregnancy does not occur, the corpus luteum degenerates in 10 days, leaving a scar (corpus albicans)  If pregnancy does occur, the corpus luteum produces hormones until the placenta takes over that role (at about 3 months)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  Repeating series of changes in the endometrium  Menses  Degeneration of the endometrium  Menstruation  Proliferative phase  Restoration of the endometrium  Secretory phase  Endometrial glands enlarge and accelerate their rates of secretion Uterine cycle

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  Control the reproductive cycle and coordinate the ovarian and uterine cycles  FSH  Stimulates follicular development  LH  Maintains structure and secretory function of corpus luteum  Estrogens  Have multiple functions  Progesterone  Stimulate endometrial growth and secretion Hormones of the female reproductive cycle

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Beginning of new cycle - Menstrual Phase of the Uterus  If fertilization does not occur, the corpus luteum degenerates and estrogen and progesterone levels decrease.  The lack of estrogen and progesterone leads to the collapse of the endometrium, which in turn leads to menstruation.

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Copyright © The McGraw-Hill Companies, Inc.

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Menstrual and prolifarative phases (corresponds Follicular Phase of Ovary)  FSH and LH increase during follicular phase because progesterone concentration is low and therefore negative feedback on these pituitary hormones is low.  FSH and LH stimulate primary follicles (containing primary oocytes) to grow and stimulate their theca cells to produce estrogen.  Estrogen leads to a thickening of the endometrium.

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  The one dominant follicle (Graafian follicle) survives because  it is hyperresponsive to FSH and can maintain itself even under low FSH  it also becomes sensitive to LH.  LH surge appears because increased estrogen exerts a positive feedback effect on the LH releasing mechanism of pituitary.  LH surge leads to release of the primary oocyte (ovulation) Menstrual and prolifarative phases (corresponds Follicular Phase of Ovary)

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Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Secretory Phase of the Uterus (corresponding to Luteal Phase of Ovary )  The now empty follicle, corpus luteum, starts secreting progesterone that exert a negative feedback on secretion from LH and FSH, preventing new follicles from maturing.  Progesterone converts the endometrium into a secretory tissue full of glycogen and blood vessels, ready to receive a fertilized egg.

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Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Menstrual phase Proliferetive phase Secretory phase Follicular/preovulatory phaseLuteal/postovulator y phase Days Hormones All lowHigh estrogen; low progesterone High progesterone; low estradiol Endometrium Necrotic tissue falls away from the uterine wall Repaired and become thicker Very well vascularized. Thick Glands Not developed. SimpleGland proliferateGlands increase in size and secrete nutritional substances Follicles Primordial follicles develop into primary and then secondary follicles One follicle continue to grow into Graafian follicle and ovulate by the end of this phase No follicular development. Corpus luteum is present Oocyte/s First meiosis; arrested in prophase IFirst meiosis completed; secondary oocyte arrested in metaphase II ovulates If fertilization occur second meiosis is completed

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Feedback Mechanisms in Ovarian Function Figure 27.21

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Gonadotropins, Hormones, and the Ovarian and Uterine Cycles