Female Reproductive Flashcards
functions of female reproductive system
- ovaries produce secondary oocyte
- uterine tubes transport oocyte to uterus
- uterus is the site of implantation of fertilized ovum and dev’t of fetus and labour
- vagina is passageway for intercourse and childbirth
- mammary glands produce milk for newborn
ovaries
a pair of organs in the upper pelvic region about the size of almonds on either side of the uterus
- produce the hormones estrogen, progesterone, inhibin and relaxin
- produce gametes: secondary oocytes which mature into ova upon fertilization
histology of ovaries
superficial to deep
- germinal epithelium: squamous to low cuboidal
- tunica albuginea: dense irregular CT outside of ovary
- ovarian cortex: dense CT that contains follicles and stromal cells
- ovarian medulla: blood/lymphatic vessels, nerves (all entering at hilum) and loose CT
stages of follicular dev’t
primordial follicle primary follicle secondary follicle mature (graafian) follicle ovulation
corpus luteum
remnant of the mature follicle
- fills in with hormone secreting cells that help uterus develop and support more follicles developing
- breaks down blood clot
- stays for 2 weeks in unfertilized stage
corpus albicans
a white scar tissue let behind after corpus luteum is not needed and is degraded
primordial follicle
all the follicles are primordial when a baby is born
- has primary oocyte
- stromal cells start to organize when cell begins to develop and make some CT
- collagen fibers make up protein component of CT
primary follicle
at puberty, follicles begin to develop
- has primary oocyte
- zona pellucida: glycoprotein layer around primary oocyte
- granulosa cells: follicular cells multiply
- theca folliculi: organized stromal cells
secondary follicle
has primary oocyte
- corona radiata: granulosa cells sticking to zona pellucida
- antrum: cavity formed by granulosa cells secreting follicular fluid that grows as follicle matures
- theca folliculi becomes 2 layers: theca externa and theca interna
mature (graafian) follicle
primary oocyte still
- granulosa cells secrete inhibin which prevents all other follicles from developing further (they will degrade or wait until next year)
theca interna vs theca externa
in secondary oocyte
interna: creates cuboidal calls that secrete estrogen which further stimulates maturation of follicle
externa: CT made of collagen fibers and stromal cells
inhibin
- secreted by a mature and dominant follicle into bloodstream to prevent other follicles from also being released and maturing
- secreted by luteal cells after ovulation has occurred
ovulation
just before ovulation, the primary oocyte becomes a secondary oocyte, the side of the ovary bulges outward and basement membrane breaks open and the oocyte gets released into the pelvic cavity
- granulosa and theca interna cells morph into a glandular strucutre: luteal cells merge into corpus luteum and produce progesterone, relaxin and inhibin
uterine (fallopian) tubes
- narrow 10cm long tubes that extend from ovary and open to uterine cavity
3 regions: infundibulum, ampulla, isthmus
infundibulum region of uterine tube
funnel shaped 1st portion of uterine tube, nearest the ovary
fimbriae
found on the end of infundibulum region of uterine tube
- fingerlike projections that sweep the oocyte into the uterine tube
ampulla region of uterine tube
central region of the tube
- covers majority of the length
- fertilization usually occurs here
isthmus region of uterine tube
= narrow area
- the narrowest part of the tube that joins the uterus
histology of uterine tubes
3 layers:
- mucosa: ciliated simple columnar and peg cells (microvilli and secrete nutritious fluid)
- muscularis: inner thick circular, outer thin longitudinal smooth muscle (for peristalsis)
- serosa: outer serous membrane: visceral peritoneum
function of uterine tubes
events occurring in the uterine tubes are as follows:
- fimbriae sweep oocyte into tube
- cilia and peristalsis move it along
- sperm reaches oocyte in ampulla and fertilization can occur within 24 hours after ovulation and zygote reaches uterus in 6-7 days (blastocyst implants)
uterus
site of menstruation and development of fetus
- 7.5cm long by 5cm wide and 2.5 cm thick bc very muscular
3 regions: fundus, body and cervix
uterine fundus
- top portion, most muscular
cervix
- canal needs to widen to give birth
- interiorly contains uterine cavity accessed by cervical canal
broad ligament
created by a fold in the visceral peritoneum that attaches the uterus to pelvic cavity on either side
ovarian ligament
holds ovary onto uterus inside pelvic cavity
isthmus of uterus
narrowing portion of uterus towards cervix region
histology of uterus
layers:
- endometrium: composed of stratum functionalis and stratum basalis
- myometrium
- perimetrium
endometrium
innermost layer
- simple columnar epithelium (some ciliated)
- areolar CT
- endometrial glands secrete nutrient rich fluidss
2 regions are stratum functionalis and stratum basalis
stratum basalis vs stratum functionalis
basalis: always there, builds up functionalis layer and makes it very vascular, closest to myometrium
functionalis: changes, is closest to uterine cavity (lumen); if implantation does not occur, then it gets sloughed off as menstrual flow
myometrium
layer that contracts to push baby out
3 layers of smooth muscle: inner/outer is longitudinal or oblique, middle layer is circular
- thickest at fundus
perimetrium
visceral peritoneum drapes overtop of uterus and fallopian tubes and folds to create the broad ligament
vagina
connects uterus to outside of the ball
- passageway for birth, menstrual flow and intercourse
- 10cm long fibromuscular canal ending at cervix
- lies between urinary bladder and rectum
histology of vagina
- mucosa: stratified squamous epithelium with rugae to allow stretch
- muscularis: outer circular/inner longitudinal smooth muscle allows for some stretch
- adventitia: loose areolar CT binds to other organs
hymen
membrane that partially closes vaginal orifice
- is there until ruptured by something like heavy menstrual flow, tampon use or intercourse
vulva
aka pudendum
- external genitalia
mons pubis
fatty pad that covers pubic symphysis
labia majora and minora
folds of skin encircling vestibule, usually closed to protect from outer enviroment
clitoris
small mass of erectile tissue, found where minoras come together and makes a little cap
bulb of vestibule (vulva)
masses of erectile tissue just deep to labia on either side of vaginal orifice
- when fills with blood, expands and closes off opening to vagina and puts pressure on penis
female reproductive cycle
controlled by monthly hormone cycle of anterior pituitary, hypothalamus and ovaries
ovarian cycle
changes in the ovary during and after the maturation of the oocyte (such as the follicle changing because of hormones
uterine cycle
preparation of uterus (endometrium) to receive fertilized ovum
- in implantation does not occur, the stratum functionalis is shed during menstruation (blood supply is cut off from functionalis layer)
hormones involved in regulation of the female reproductive cycle
gonadotropin-releasing hormone (GnRH) follicle stimulating hormone (FSH) luteinizing hormone (LH) progesterone estrogen relaxin inhibin
gonadotropin-releasing hormone (GnRH)
released from hypothalamus
- controls cycles by stimulating the release of follicle stimulating hormone and luteinizing hormone from the anterior pituitary
follicle stimulating hormone (FSH)
stimulates growth and development of follicles that secrete estrogen
luteinizing hormone (LH)
stimulates ovulation and promotes formation of the corpus luteum which secretes estrogen, progesterone, relaxin, and inhibin
progesterone
works with estrogens to prepare uterus for implantation and stimulates the functionalis layer to build up
- high progesterone inhibits release of LH and FSH
estrogen
maintains reproductive organs
- is secreted by theca interna cells of secondary follicle and then comes from corpus luteum after ovulation
- moderate levels of estrogen inhibit LH and FSH release
- high levels of estrogen stimulates LH and FSH release
relaxin
secreted by corpus luteum
- facilitates implantation by relaxing the uterus to create the optimal environment for the blastocyst
inhibin
secreted from granulosa cells of secondary follicle and then by corpus luteum
- inhibits secretions of FSH
luteal cells
granulosa cells and theca interna cells get mixed up to become luteal cells which make up the corpus luteum
phases of the reproductive cycle
typically lasts 24-36 days (average is 28) Phases: 1. menstrual 2. preovulatory 3. ovulation 4. postovulatory
menstrual phase
menstruation lasts for about 5 days and the first day is considered the beginning of the 28 day cycle
- ovary in follicular phase
ovary in menstrual phase
- follicles are at various stages of development and it usually takes months to reach maturity
- FSH stimulates primordial follicles to from primary follicles to secondary follicles
uterus in menstrual phase
- declining levels of progesterone and estrogens cause spiral arteries that supply functionalis layer to constrict leading to cell death (bc of lack of oxygen)
- stratum functionalis layer is sloughed off along with 50-150mL of blood/fluid/cells
preovulatory phase
lasts from day 6 to 13 (most variance in timeline)
- ovary is in follicular phase
- uterus is in proliferative phase
ovary in preovulatory phase
follicular phase
- secondary follicles secrete estrogen and inhibin which slows secretions of FSH causing other follicles to stop growing
- one dominant follicle survives to day 6
by day 14, mature follicle secretes more and more estrogen and has enlarged and bulges surface of ovary
- the increasing estrogen levels trigger LH secretion
uterus in preovulatory phase
proliferative phase
- increasing estrogen levels have repaired and thickened the stratum functionalis layer to 4-10mm thickness
- cells of basalis layer start to multiply and build functionalis layer on top
ovulation
high levels of estrogens from almost mature follicle stimulate release of more GnRH and LH
- in anterior pituitary, GnRH promotes release of FSH and more LH
- the surge in LH causes ovulation, rupturing follicle and releasing secondary oocyte on day 14
- corpus hemmoragicum results which starts to build corpus luteum right after
postovulatory phase
lasts 14 days
the time between ovulation and menses
- ovary in luteal phase
- uterus in secretory phase
ovary in postovulatory phase
luteal phase
- corpus luteum forms under the amount of LH and begins to secrete more hormones
- if no fertilization: corpus albicans is formed by 2 weeks which degrades and the hormones produced by the corpus luteum and corpus albicans decrease: as these hormone levels drop, secretion of GnRH, FSH and LH rise
- if fertilization occurs: developing embryo secretes human chorionic gonadotropin (hCG) which maintains healthy corpus luteum and its hormone secretions
uterus in postovulatory phase
secretory phase
- hormones from corpus luteum promote thickening of endometrium to 12-18mm
- if no fertilization: corpus luteum dies (estrogen and progesterone levels drop) and menstrual phase will begin
ovulation kits
detect the spike in LH that arises during (12 hours prior to) ovulation
- can be detected in urine thus can determine when someone is ovulating
pregnancy tests
detect the hormone hCG (human chorionic gonadotropin) present and secreted by developing embryo
human chorionic gonadotropin (hCG)
- secreted by embryo
targets corpus luteum and keeps it alive
so that it will secrete the regular hormones and stop the menstrual cycle from happening
