Female Reproductive System - Past Paper PDF

Today’s Learning Objectives Describe the stages of oogenesis. Follow an ovulated egg through the female reproductive tract, identifying each structure passed and what the function of that structure is. Draw a diagram which explains the ovarian cycle, what hormones are involved and...

Today’s Learning Objectives Describe the stages of oogenesis. Follow an ovulated egg through the female reproductive tract, identifying each structure passed and what the function of that structure is. Draw a diagram which explains the ovarian cycle, what hormones are involved and when. What is the external hormonal influence on the female reproductive cycle? Describe biological influence on female fertility. What birth control options are there available to females and how do they work? What is menopause? Describe the process of fertilization in detail. Describe the stages of development from zygote to birth of a newborn. What major hormones control this process. What is the relationship between the mom and the fetus with regard to intrauterine membranes? Describe the process and hormones involved in labor and delivery. Reminders Complete Lab Quiz 6 by Thursday at 11:59pm Urinary Lab is due by Thursday at 11:59pm Anything else you want to submit, must be complete by Thursday at 11:59pm! Wednesday: NO LAB Finish Reproductive and Review! Thursday: NO LAB 12:30-1:55 pm Exam 5 Think-Pair-Share: Why do women have a biological clock? And by what age should a woman get pregnant?  Men have a biological clock too https://pubmed.ncbi.nlm.nih.gov/18711662/ #:~:text=Thus%2C%20paternal%20age%20is%20a,as%20diabetes%20an d%20cardiovascular%20diseases. A tampon tax (pink tax) is a popular term used to call The Pink Tax attention to the fact that tampons—and other feminine hygiene products—are subject to value-added tax, unlike the tax exemption status granted to other products considered basic necessities. No sales tax: Alaska, Delaware, Montana, New Hampshire, Oregon Exempted essential hygiene products: Connecticut, Florida, Illinois, Maryland, Massachusetts, Minnesota, New Jersey, New York, Nevada, Pennsylvania Female Reproductive Organs Ovaries: female gonads; site of oocyte and sex steroid production Uterine (Fallopian) tubes: have fimbriae that partially wrap around the ovaries and “catch” the oocyte after ovulation – Most common site of fertilization 8 Female Reproductive Organs Uterus: site of embryonic development Endometrium: inner layer, where embryo implants and develops; made of the stratum basale and stratum functionale Myometrium: middle smooth muscle layer; contracts to expel baby at birth Perimetrium: outer connective tissue layer Cervix: narrow bottom region of uterus 9 Female Reproductive Organs Vagina: organ of copulation, opens between the labia (majora and minora) Clitoris – erectile tissue 10 Female Reproductive Organs 11 Homologous Structures  Think-Pair-Share Review the process of spermatogenesis with a partner, beginning with a spermatogonium like the one below. Beginning of Oogenesis Toward end of gestation, oogonia begin meiosis to produce primary oocytes. Oogenesis is stopped at prophase I of meiosis I. The ovaries of a newborn have 2 million primary oocytes. By puberty, cut to ~400,000. Only about 400 of these will be ovulated in her lifetime 14  Childhood Female’s ovaries are inactive and no follicles develop Atresia: primordial follicles die (like apoptosis) 15 Egg Development in the Ovary  Oogenesis Mitosis begins in utero and meiosis I is arrested at prophase I until… Mitosis Complete at ovulation Complete at fertilization Oogenesis The secondary oocyte begins meiosis II, but stops at metaphase II. Meiosis II will complete, only if there is fertilization of the ovum. 18 Stages of Ovum and Follicle Development Access the text alternative for slide images 19 Review Question Describe at least 3 differences between spermatogenesis and oogenesis. Follicles ©Victor P. Eroshenko Access the text alternative for slide images 21 Review Question Why do females have a “biological clock”? Cyclic Changes in the Ovary and Uterus Insert fig. 20.35 Endocrine Control of the Ovarian Cycle Corpus luteum Ovulation Cyclic Changes in the Ovaries Follicular changes in the ovaries can be broken into three phases: a. Follicular phase b. Ovulation c. Luteal phase 25  A. Ovarian Follicular Phase Lasts from day 1 through 13 (variable) Primary follicles → Secondary follicles → Graafian follicle (one kept, others go through atresia) Characterized by increasing levels of estradiol (estrogen) production from granulosa cells, reaching a high around day 12 26  A. Ovarian Follicular Phase Initiated by FSH FSH upregulates the number of FSH receptors on the follicles → increased sensitivity to FSH FSH and increased estradiol stimulate production of LH receptors on mature follicle Increased estradiol also stimulates the hypothalamus to release more GnRH → LH is released from anterior pituitary – + feedback – Called the LH surge 27 B. Ovulation FSH causes the Graafian follicle to bulge out of the ovary wall, like a blister LH surge begins ~24 hours before ovulation. Stimulates Graafian follicle to rupture, releasing secondary oocyte 28 C. Luteal Phase After ovulation, LH stimulates the ruptured follicle to become a corpus luteum. 1. The corpus luteum secretes estradiol and progesterone. 2. Progesterone peaks ~1 week after ovulation. 3. High levels of estradiol and progesterone feedback on the pituitary gland and inhibit FSH and LH secretion. 29 C. Luteal Phase (cont) 4. Follicle development shut down to prevent further ovulation long enough to give the secondary oocyte a chance to be fertilized 5. Ends with the degeneration of the corpus luteum around day 28 6. Decreasing levels of estradiol and progesterone stimulate the sloughing of the endometrium and menstruation. 30 Review Question Take a moment and review what is occurring in the three phases of the ovarian cycle: a. Follicular Phase b. Ovulation c. Luteal phase What hormones are signaling for this phases to occur?  Methods of Female Birth Control What are they? How effective are they?  Methods of Female Birth Control Oral contraceptives work by mimicking progesterone to prevent ovulation. How would this work? What does it “trick” your body into thinking? Contraceptive Methods 1. Contraceptive Pill – Includes synthetic estradiol and progesterone – Acts like a prolonged luteal phase – Produces negative-feedback inhibition of GnRH, so ovulation never occurs – Endometrium still proliferates. – Placebo pills are taken for 1 week to allow menstruation. 35 Contraceptive Methods 2. Vaginal ring and contraceptive patch a. Deliver contraceptive steroids through a mucous membrane or skin b. Permits lower dosage than oral contraceptives 3. Long-acting reversible contraceptives (LARC) a. Intrauterine devices (IUDs) – prevent fertilization b. Subdermal hormonal implants – contain progestin that inhibits ovulation and thickens cervical mucus 36 Contraceptive Methods 4. Rhythm Method of Contraception A woman can time ovulation by taking her temperature. This is a pretty good indicator for when ovulation occurs but not a very reliable form of birth control. 37 Menopause Characterized by cessation of ovarian activity and menses Due to changes in the ovaries, not to decreases in FSH and LH FSH and LH levels are actually elevated due to lack of negative feedback. Usually occurs after age 50 Symptoms are due to loss of estradiol. Hot flashes are produced by vasomotor disturbances. The walls of the urethra and vagina atrophy, and vaginal glands no longer produce lubrication. After menopause, risk for atherosclerosis and osteoporosis increases. Estradiol is needed for bone deposition, so menopausal women are at increased risk for osteoporosis. – Adipose tissue does make a weak form of estradiol – Heavier women thus have a reduced risk of osteoporosis. 38 Fertilization, Pregnancy and Parturition  Acrosome Reaction Acrosome: contains enzymes that digest a channel through zona pellucida to oocyte If an egg is fertilized…what happens next?  Implantation ~5 days after fertilization, blastocyst (developing embryo) attaches to endometrium HcG is secreted by trophoblast Hormonal Control of Pregnancy hCG binds to LH receptors, which leads to production of estrogen and progesterone (by corpus luteum) hCG helps maintain corpus luteum Later, placenta produces progesterone leading to development of endometrium Estrogen is critical for mammary glands devp Labor is Stimulated by Oxytocin Parturition  Lactation Mammary gland: – Lobules contain glandular alveoli that secrete milk of the lactating female. Milk-Ejection Reflex