Female Reproductive System and Health

• The topic is reproductive system II, specifically the female reproductive system.

Agenda

• Welcome, announcements and check in take 5 minutes
• Learning outcomes will be discussed over 2 minutes
• Interactive lesson for approximately 33 minutes
• Class ends 10 minutes early

Office Hours

• Office hours on Tuesdays, 8-9am, in person at BSIF 1217
• Office hours on Wednesdays, 4-5pm, Zoom tab on the Canvas page

Office Hour Help

• In office hours you are able to study
• Can get reference letters
• Can find internship or research opportunities
• Can help to figure out your future

Learning Outcomes

• Describe the structures and functions of the female reproductive system hormonal regulation
• Explain the reproductive health conditions, including: endometriosis, PMDD, and PCOS and the effects on fertility.
• Analyze the physiological processes of ovulation, fertilization, and implantation

Why Understanding This is Important

• With reproductive rights changing across the U.S., understanding the science is key to making informed decisions.
• In order to advocate for or against reproductive healthcare policies one needs understand the biology behind them
• Reproductive health conversations must include trans and non-binary people to ensure truly accessible healthcare
• Most medical research is based on male bodies, leaving gaps in understanding how reproductive hormones affect health.

Ovaries Structure and Function

• Ovaries produce gametes and sex hormones including estrogen and progesterone
• The ovaries have a cortex that houses developing eggs, and a medulla that contains blood vessels and nerves

Ovarian Cycle

• Tiny sac-like structures hold a single primary oocyte and follicle cells around it
• Females are born with all their oocytes in the primordial follicle, around 1 million
• At birth, the oocytes stops developing and get stuck in meiosis I and stay that way for years, sometimes forever.
• Egg creation, also known as oogenesis is delayed until puberty
• Oocytes mature one-by-one and a mature eggs is either fertilized or dies to make way for a new egg.

Ovarian Cycle

• At puberty, the hypothalamus and pituitary set up two concurrent cycles
• Ovarian Cycle ripens eggs and secretes sex hormones in ovaries
• The menstrual (uterine) cycle prepares the uterus to capture and nourish any mature fertilized eggs

Days 0-13 of the Ovarian Cycle

• The hypothalamus starts the ovarian cycle by secreting GnRH, once a month, stimulating FSH and LH
• In the ovary, FSH stimulates the growth of a follicle, but only one: the one that happens to be furthest along in development at the time
• It drives one lucky follicle to keep growing by triggering the follicle itself to secrete its own estrogen hormones, which locally signal the follicle to mature even more

Day 14, Ovulation, of the Ovarian Cycle

• The follicle secreted estrogen stimulates the pituitary to secrete another pulse of LH
• LH gets to work on the oocyte that is dormant inside the follicle and triggers it to finally start dividing again to complete meiosis I and move on to metaphase II
• The mature follicle pushes up against the ovary wall, ruptures, and, with the help of enzymes, breaches the wall and ejects a single oocyte

Days 15-28

• The follicle now slows down on the release of its estrogen production, thus morphing into a new structure called corpus luteum, which eventually degenerates
• A hormonal burst of progesterone, a little estrogen, and some inhibin that together stop the release of FSH and LH.
• The uterus is prepared to receive an oocyte
• The corpus luteum is responsible for producing progesterone post ovulation, which is crucial formaintaining the uterine lining.

Uterus

• When the oocyte pushes through the ovary, it has to float a short way through the peritoneal cavity before it's caught by a fallopian tube
• If an egg fuses with a sperm it will complete meiosis II and become an ovum (egg)

Uterus Structure

• Perimetrium, the outside layer.
• Myometrium is the bulky, smooth muscle that contracts during labor.
• Endometrium, the inner mucosal lining, which consists of both a thin, deep basal layer and an outer functional layer

Ectopic Pregnancy Risk Factors

• When a fertilized egg implants outside the uterus
• Scarring or damage to the fallopian tubes from previous infections, surgery, or endometriosis
• A history of infertility
• Use of intrauterine devices (IUDs)
• In vitro fertilization (IVF)

IVF (In Vitro Fertilization)

• Ovarian stimulation hormone therapy
• Egg pick up, also known as aspriration
• Sperm preparation
• Egg fertilization through intracytoplasmic sperm injection
• Enbryo devleopment
• Embryo transfer

Menstrual Cycle

• If fertilization happens, the embryo snuggles into the endometrium for gestation, receptive to implantation for one week post ovulation
• If the egg isn't fertilized, the outer, functional layer sloughs off due to hormonal imbalances.
• Shedding occurs from days 1-6
• Days 7-12 involve FSH and LH released from the anterior pituitary and start to rise, stimulating the next round of follicles, who begins to make estrogen (Day 14)
• The rising estrogen levels in the follicles stimulate the regeneration of the endometrium, building a well-vascularized habitat for a potential fertilized egg to call home.
• Day 15-28, also known as post ovulation, if no fertilization occurs the corpus will stop producing progesterone and the endometrium will shed its functional layer
• But IFF it fertilization did occur, another pulse of progesterone from the corpus triggers even more thickening of the functional layer of the endometrium.

Endometriosis

• Abnormal growth of endometrial tissue outside the uterus
• Thought to be due to retrograde menstruation (backward flow of period), immune dysfunction, or genetic factors, leading to pain and fertility issues
• The tissue responds to estrogen, causing chronic inflammation, scarring, and nerve sensitization

PMDD (Premenstrual Dysphoric Disorder)

• Thought to be caused by a reaction to abnormal hormone fluctuations, affecting serotonin levels and leads to severe mood and physical symptoms before menstruation
• Changes in progesterone and estrogen levels alter serotonin, impacting mood regulation

PCOS (Polycystic Ovary Syndrome)

• Caused by hormonal imbalances, often linked to insulin resistance and excess androgens, leads to irregular periods, ovarian cysts, and metabolic issues
• Elevated insulin levels stimulate the ovaries to produce excess androgens, disrupting ovulation and leading to cyst formation

Birth Control, Historical Contexts

• Crocodile dung pessaries. Ancient Egypt, 1850 BCE: included crocodile dung, honey, and sour milk
• Mercury & Lead Consumption, Ancient China & Greece: caused infertility or death
• Silphium Plant, Ancient Rome & Greece: powerful contraceptive. Overharvested led to extinction
• Weasel testicles, Medieval Europe, amulet to ward off pregnancy

Birth Control, Historical Contexts (continued)

• 1800s – Early Bans and Advocacy: illegal action in the U.S.
• 1910s-1930s - Birth Control Movement: Margaret Sanger opened the first birth control clinic
• 1960 – The Pill: FDA approved the first oral contraceptive, “Enovid”
• 1970s - Legal Victories: The right to contraception was made legal
• 1990s-2000s - Plan B & Affordable Access : emergency contraception
• 2010s-Present - The trump administration restricted contraceptive coverage
• 2022 - Dobbs decision overturns abortion

Birth Control, Modern Methods

• Combined Hormonal Contraceptives (CHCs) include pills, patches, and vaginal rings. Inhibit ovulation, thin the uterine lining
• Progestin-Only Methods include pills, injections, implants, and IUDs, these methods thicken cervical mucus to block sperm, thinning the uterine lining to prevent implantation, and sometimes suppressing ovulation
• Injectable and Implantable Progestins provides long-term contraception by altering ovulation and thickening cervical mucus and up to 5 years of protection
• IUD (Intrauterine Device) contains progestin with reduces or stops periods by thickening cervical mucus and preventing ovulation or fertilization