Female Reproductive system Flashcards
cyclic changes in activity=
menstrual cycle
restricted periods of fertility=
ovulation
limited gamete production=
pool established at birth
female gonads
ovaries
reproductive tract contains
uterus, uterine tubes and vagina
external genitalia
vulva
follicle=
oocyte(ovum)+ single epithelial layer
follicles are developed in the
ovary
what happens as the follicle develops
-there is an increase in epithelial cell layers and they become granulose cells
some granulosa cells become
theca cells (secretes androgens that are converted to estrogen by granulose cells)
what are granulose cells and what do they secrete/function?
- target cells of estrogen and FSH
- secrete chemical messengers in response (targets oocyte)
- also secrete inhibin (negative feedback for FSH)
- tramsport nutrients to oocytes through gap junctions
- secrete estrogen and progesterone
uterus function
- site of fetal development
- Body:upper portion
- cervix:canal leading to vagina
- cervix+vagina =birth canal
wall of the uterus (3 layers)
- outer layer: perimetrium
- middle layer:myometrium
- inner layer:endometrium
outer layer contains
epithelial cells and connective tissue
describe middle layer
- smooth muscle
- thickest layer
- layer of epithelial cells ‘
- layer of connective tissue
- numerous glands
describe the vagina
- female organ of copulation
- wall contains smooth muscle
- inner surface bathed in acid fluid secreted from uterus or glands in cervix to protect against infections
describe the uterine tubes
- also called fallopian tubes pr oviducts
- ova transported from ovaries to uterus
- site of fertilization
- duration is 4 days to uterus
oogenesis:
oogonia->ova
how many oogonia do females have?
fixed number at birth, unlike males who continually produce spermatogonia
when does meiosis began
in the fetal life
when is meiosis completed
only after fertilization
how many oocytes rupture during a females life
approximately 400
what are the sexual responses in females
- vascular congestion of clitoris
- vaginal secretions
- nipple erection
- orgasm
what happens during an orgasm
- rhythmic contractions of vagina and uterus
- increased blood pressure and heart rate
- widespread skeletal muscle contractions
menstrual cycle includes two sub cycles
- ovarian cycle
- uterine cycle
the menstrual cycle is caused by?
changes in estrogen and progesterone
what are the ovarian cycle phases
- follicular phase
- luteal phase
what is the follicular phase and how long does it last
- menstruation -> ovulation
- lasts apporx 14 days
what is the luteal phase and how long does it last
- ovulation-> before menstruation
- lasts approx 14 days
what happens in the follicular phase
- GnRH surge causes LH surge
- LH surge triggers ovulation and development of corpus luteum in luteal phase
- Ovulation: wall of Graafian follicle ruptures
- Antral fluid with oocyte flows to ovary surface
- Oocyte is released and enters fimbrae
- Atresia = degeneration of follicles ~ 1000+ follicles are lost per month (of the 400k that are available at puberty)
what happens in the follicular phase
-FSH and estrogens stimulate follicle growth and development
-A few follicles develop from primordial follicles
-Oocyte grows; granulosa cells proliferate
-Zona pellucida and antrum form
-Dominant follicle continues development; remaining follicles regress
-Corona radiata develops
-Graafian follicle = mature follicle
Ovulation
what happens in the luteal phase
- Ruptured follicle → gland = corpus luteum
- Corpus luteum scretes estrogens and progesterone
- Corpus luteum reaches maximum activity in 10 days, then degenerates (luteolysis)
- Luteolysis → decreased estrogens and progesterone → menstruation (end of luteal phase)
- If oocyte is fertilized, degeneration does not occur
how do fraternal twins happen
- Two or more follicles may become dominant and released at ovulation
- If both are fertilized, fraternal twins result
- Also called dizygotic twins (develop from two zygotes
the uterine cycle
- mentstrual phase
- proliferative phase
- secretory phase
describe the menstrual phase
- 3-5 days
- triggered by fall in estrogen or progesterone
- endometrial layer of uterus sheds
- rupture of blood vessels after vasoconstriction causes the tissue to die and separate from uterus
describe the proliferative phase
-uterus renews
-smooth muscle thickens ans glands enlarge
-increased blood vessels, mucus secretions from cervix
-
describe secretory phase
- uterus ready for implantation
- further arterial growth and gland enlargement + glycogen
- cervical plug
- thickened mucous secretions from the cervix “plug” the uterus from microorganisms entering via the vagina and damaging the growing embryo
- progesterone promotes these changes
what are the hormonal changes during the menstrual cycle
- Estrogen is first secreted from follicles, then from the corpus luteum
- Progesterone is secreted from corpus luteum
- LH and FSH are secreted from anterior pituitary gland
- Estrogens and progesterone inhibit LH and FSH secretion
hormonal changes in the early to mid follicular phase
- Short-lived declines in plasma estrogen and progesterone (final stages of luteolysis)
- LH and FSH consequently increase slightly
- FSH binds to receptors on granulosa cells, causing follicles to grow
- FSH causes the outer granulosa layer to differentiate into thecal cells
- LH acts on thecal LH receptors to stimulate testosterone synthesis –Testosterone is converted by granulosa cells into estrogens
- Estrogen concentrations increase: negative feedback on GnRH and LH and FSH
- LH and FSH levels remain constant but estrogens continue to rise due to proliferating cells and increased LH and FSH receptors
changes induced in dominant follicle under influence of LH surge
- Meiosis I completed
- Estrogen declines
- Progesterone production by granulosa cells initiated
- Enzymes secreted, breaking down follicular wall
- Follicular wall ruptures 18 hours after surge peak
- Granulosa and theca cells differentiate into luteal cells
hormonal changes in luteal phase
- Estrogen levels continue to decline
- LH surge is terminated
- Progesterone from luteal cells increases
- Promotes uterine development and preparation for pregnancy
- Powerful inhibitor of GnRH and LH/FSH secretion
after 10 days what happens in the luteal phase to the hormones
- absence of implantation, corpus luteum starts to degenerate (spontaneous in humans)
- Progesterone and estrogen decline, triggering menstruation
- Actions of progesterone:
- Promotes secretory-phase uterine conditions
- Suppresses uterine contractile activity
- Promotes growth of glandular tissue in breasts
- Suppresses milk production
how long can sperm survive in reproductive tract of the female
5 days (only a few hundred make it to the uterine tubes0
what happens when the sperm reach the ovum
- try penetrating the corona radiata
- When they get through the corona radiata, sperm bind to sperm-binding protein
- Acrosome reaction is triggered, with acrosomal enzymes released
- Enzymes break through the zona pellucida, allowing sperm to access the oocyte
what happens at ovulation
-fluid movement causes the oocyte
to enter the fimbriae of the uterine tube
-Peristaltic contractions move the oocyte toward the uterus for several minutes
-Activity of cilia move the oocyte toward the uterus for a few days
-Entire trip takes four days
-Sperm must meet ovum during these four days
where does fertilization take place and what is required for sperm to fertilize
- uterine tube
- requires capacitation
what is sperm capacitation
-Capacitation occurs in female reproductive tract
=Tail movement
=Plasma membrane altered
mitotic divisions ->morula
Cell cleavage (no increase in overall size) Totipotent until the 16- to 32-cell stage
blastocytes
Lost zona pellucida Outer cell layer: trophoblast Will become fetal placenta Inner cell mass Will become embryo Fluid-filled cavity: blastocele
how long is implantation and what happens
- Occurs 6–7 days post fertilization
- Trophoblast is responsible for implantation
- Secretes enzymes that digest endometrial cells to provide nourishment for the embryo
- Secretes paracrines that stimulate the decidual response
- Infiltrates endometrial tissue to develop into the placenta
development of embryo to fetus
- In region of contact between embryo and uterine wall, trophoblast thickens → chorion
- Amniotic cavity forms
- Amnion (amniotic sac) contains amniotic fluid
- Week 5: heart, spinal cord, and GI tract start to develop
- Week 6: heart beating
- Week 8: lungs develop
- Week 9: remaining organs develop
- Week 10: size of kidney bean = fetus
placenta development
- Fetal component
- Chorionic villi
- Maternal component
- Endometrial tissue
- Blood flow to placenta
- Maternal uterine artery and vein
- Fetal umbilical artery and vein located in umbilical cord
- By 5 weeks, placenta is functioning and heart is beating
hormonal changes during pregnancy
- hCG recreated from placenta (sustains corpus luteum)
- first two months (estrogen and progesterone secrete by the corpus luteum)
- rest of pregnancy (placenta takes over secreting progesterone and estrogen, progesterone inhibits GnRH, prevents LH surge
estrogen:
- Growth of duct tissue in the breasts
- Prolactin secretion
- Growth and enhanced contractile responsiveness of smooth muscle in uterus
- Oxytocin
progesterone:
- Growth of glandular tissue in the breasts
- Maintenance of secretory-phase uterine conditions
- Suppression of contractile activity of smooth muscle in uterus
how long is pregnancy
40 weeks
what is parturition
birth
what is lactation
milk production in mammary glands
what is the trigger for parturition
unknown, but think it comes from the fetus
what happens at end of pregnancy
cervix ripens
what happens at beginning pf parturition
- cervix dilates
- labour (uterine contractions)
what happens at partiruition
- Baby’s head wedges cervix open
- Baby is born head first
- Expulsion of placenta: afterbirth
what inhibits lactation
estrogen and progesterone
what stimulates lactation
- prolactin stimulates milk synthesis
- oxytocin stimulates the milk ejection reflex
what is colostrum
- watery milk produced in the first few days after birth
- contains proteins, but few nutrients
what is in later milk
nutrients, growth factor, hormones and antibodies
exercise and the male reproductive system
- Little impact
- Exercise alone
- No decrease in testosterone observed during HI exercise
- No change to LH or semen quality
female athlete triad
Amenorrhea, osteoporosis, disordered eating
what is the name of RED-S
relative energy deficiency in sport
what is RED-S
inadequate energy intake to support body functions related to health and performance
RED-S system impact
- Reproductive
- Skeletal
- Metabolic
- Immune
- Cardiovascular
- Impact to health and athletic performance
- Males and females
