Femeal Reproductive Physiology Flashcards
What are the two main phases of the female reductive system?
1) preparation of the female body for conception
2) maintain a pregnancy
Where do LH and FSH work on in the ovary
LH = theca cells
- function to promote follicular development development
FSH = granulosa cells
- function is to produce estrogen and progesterone
How does estradiol and progesterone affect GnRH release?
Estradiol
- promotes LH release
- inhibits FSH release
Inhibin A/B
- inhibit FSH release
Progesterone
- promotes FSH release
- inhibits LH release
What is included in the “vulva”
Labia majoria + minora
Mons pubis
Clitoris
Vestibule of the vagina
Vestibular bulbs
External urethral orifice
Homologous anatomical structures in women based on male counterparts
Labia majoria = scrotum
Clitoris = penis
Vagina structure and function
Is lined with nonkeritinized stratified squamous epithelium
- also possesses a thick lamina propria layer with enriched elastic fibers
Does not lubricate its self instead gets from
- cervical mucus
- transudate from blood vessels of the lamina propria
- secretions from greater vestibular gland
Vaginal wall has three layers
1) mucosa
2) Muscularis
3) adventitia
The vagina is innervated by the pudendal nerve
Is affected by three primary hormones
1) estrogen = stimulates proliferation of vaginal epithelium
2) estradiol = induces minimal keratinization of the apical layers
3) progesterone = increases desquamation of the epithelial cells
- *glycogen metabolism in the vagina causes lactic acid build up by commensal lactobacillus
- this reduces infections of bacteria and fungi**
Cervix structure and function
Inferior extension of the uterus that projects into vagina
acts as the gateway into the upper female tract
- during mid cycle (ovulation) = facilitates sperm viability and entry into the Fallopian tubes
- during the luteal phase = serve to impede the passage of sperm and microbes (lowers chance of superimplantation of second embryo and infections
DOESNT undergo menstration changes and can physical support the baby’s weight during pregnancy
Hormonal regulation of the cervical mucosa during menstral cycle
Estrogen = stimulates production of copious quantities of thin and watery slightly alkaline mucus
- ideal environment for sperm
Progesterone = produces viscous acidic mucus that is hostile to sperm
- is hostile to sperm and forms a barrier within the endocervical can also during secretory phase of the endometrium and pregnancy
Uterus anatomy
Single organ that sits in the midline of the pelvis between rectum and bladder
Has 4 parts
- fundus = superior portion that rises superiorly from the entrance of the oviducts
- the body = most of the uterus and site of embryoblast implantation
- the isthmus = narrowed part of the body connecting the Fallopian tubes on each side
- cervix = most inferior portion
Functions to
1) provide a suitable site for attachment and implantation for the blastocyst with a nutrient rich stroma
2) limit the invasiveness of the implanting embryo so it stays in the endometrium
3) provide a maternal side of the mature placental architecture
4) grow and expand with the growing fetus
5) provide strong muscular contractions that expel the fetus at birth
Structure of the uterine endometrium
Endometrium = mucosa of the uterus
2/3rds of the luminal side of the endometrium is lost during menstration
- this is called the functional zone or “stratum functionalis”
- is fed by spiral arteries
1/3rd of the luminal side remains tonic even during menstration
- this is called the basal zone or “stratum basale”
- is fed by straight arteries
- contains all cell types of cells of the endometrium
Endometrial cycle
is controlled primarily by estradiol and progesterone primarily and is a cyclic monthly growth and breakdown
3 primary phases
1) proliferative phase = 1-11th days
2) secretory phase = 12-24th days
3) menstrial phase = 25-29th days
after menstruation, the endometrium is restored within 5 days
- this is stimulated by estrogen from developing follicles
- however estradiol primary does the proliferation since it stimulates (IGF, TGF, EG) factors by endometrial cells which work in paracrine fashion to induce maturation and growth of the endometrium
Progesterone. Opposes estradiol during the luteal phase by up regulating 17B-HSD enzymes. These enzymes convert estradiol -> estrone which is a weaker estrogen. Also decreases ER levels in endometrial cells
- all of progesterone effects halt the proliferative phase of the endometrial cycle
If the oocyte is not fertilized within 14 days of ovulation, a sudden drastic drop in estradiol and progesterone will occur and cause demise of the corpus luteum
- the functional layer of the endometrium begins to atrophy and break down (signaling the start of the 1st day of the menstrual cycle/phase)
Ovulation/ovarian cycle
Occurs in tandum with endometrial cycle
Contains 4 main events
1) folliculogenesis
2) ovulation
3) formation of the corpus luteum
4) atresia/death of the corpus luteum
3 phases
1) follicular phase
- days 0-14 and aligns with proliferative phase (which is proliferation for he functional layer of the endometrium)
- the follicle develops in the ovaries as well and releases estrogen tonically which helps endometrial growth
2) ovulation phase
- roughly day 15 and is in between secretory and Proliferative phases
- begins when the follicle is mature and ruptures releasing an ovum
3) luteal phase
- roughly day 15/16 - 28 and lines up with secretory phase
- begins with transformation fo the follicular cells into a corpus luteum and further proliferates the endometrium
- if fertilization doesnt occur, then menstral cycle occurs roughly 18 days in for 3-5 days.
What causes the sudden rise in Basal Body Temperature (BBT)
During every ovulation cycle the body the increases in internal temperature in 0.3-0.5C
- this is due to progesterone release by the corpus luteum
can be seen iatrogenic if injecting progesterone and progestogen
Fallopian tubes (oviducts)
Muscular tubes at each end of the uterus with a “infundibulum” at the ends of both tubes
- infundibulum = contains cillia that helps move oocyte towards the uterus
- also contains “peg cells” which help nourish and support ovum, sperm and zygote if fertilization occurs in the tubes
3 main functions
1) capture the oocyte-cumulus complex at ovulation and transport it to the uterus
2) provide a site for sperm storage (can stay there for 5 days)
3) providing nutritional support to the preimplantation embryo by its secretions
- *is promoted/proliferates in response to estrogen**
- increases blood flow to the lamina propria of the oviducts and concentration of glucose proteins
- increases secretion of thick mucus in the isthmus
- also increases tone of the isthmus to keep oocyte complex there for fertilization
if exposed to high progesterone though, decreases cell sizes and function of the oviducts
When does the blastocysts typically implant in the uterus?
Around day 5 or 6
