Lecture 8 - Female reproduction Flashcards
The uterus faces?
anteriorly
how is the uterus kept in place?
by a series of ligaments
why is positioning of the uterus important?
because the ovaries are not connected to the uterus in humans
what are the three main ligaments and their functions?
- broad ligament (stops lateral movement of the uterus)
- suspensory ligament (connects the overies to the pelvis wall and contains the ovarian blood vessels)
- ovarian ligament (connects the overies to the uterus)
oocytes are produced during?
gestation, at about 6-8 moths
how many oocytes does a female have at birth?
1 million
what are the two pituitary hormones of the female reproductive system?
Follicle stimulating hormone
Luteinizing hormone
what are the two main ovarian hormone levels?
estrogens and progesterone
what are the new boundaries for 1º, 2º and 3º follicles?
1º = single layer of granulosa cells
2º = multiple layers of granulosa cells
3º = antrum formed
how long does it take from the time of follicle activation to ovulation?
about 85 days
true or false, each menstrual cycle, a follicle is chosen to be activated.
false, groups of follicles are stimulated to grow rapidly (this is the follicular wave) but only one is dominant and is ovulated
where is the fundus of the uterus?
at the top, points anteriorly
what is a retroflexed uterus?
when the uterus points slightly posteriorly rather than anteriorly
what is intersting about a retroflexed uterus and birth?
babies in a normal antiflexed uterus must rotate 90º before birth. In a retroflexed uterus, this doesn’t need to change
how does uterine volume change during pregnancy?
goes from about 10ml of volume to 5L (for one baby on average)
what does the massive change in uterine volume tell us about the uterus activity?
- massive physiological changes must happen in the uterus during pregnancy
the bottom of the uterus is continuous with the ________
cervix
what are the three layers of the uterus?
serosa (aka perimetrium)
myometrium
endometrium
describe the myometrium
- makes up 90% of uterine tissue
- main function is forceful expulsion of fetus
- doesn’t change during menstrual cycle
describe the contractions of the myometrium during the menstrual cycle
- during the proliferative phase the contractions are generally upwards (which may aid sperm)
- during the secretory phase, contractions are usually downwards (which may aid embryo transport)
describe the layers of the endometrium
- simple columnar epithelium
- functional layer (the bit that changes over the menstrual cycle)
- basilar layer (connects to myometrium)
which day does the endometrial cycle start?
on the first day of the menstrual bleed (menses)
describe the glands over the course of the endometrial cycle
glands begin to form in proliferative phase but are inactive and there are lots by the secretory phase to provide nutrition for implanting embryo
what is the decidua?
the tissue that is lost during menstruation and the tissue that undergoes the decidual reactions
how is implantation different in humans than it is to other animals?
the embryo implants entirely inside the wall of the uterus (implantation into decidua)
what is the decidual reaction?
the stroma of the endometrium becomes oedematous (secretory) stromal fibroblasts expand and fill with glycogen, which acts as an energy source for the embryo
how is the decidual reaction different in women than to other species?
usually they happen after implanation in other species, but ours happens before and happens every menstrual cycle
what is the window of implantation?
a 48 hour window in which the endometrium is receptive
- expression of adhesion molecules which interact with the trophectoderm on the blastocyst
what are pinopodes?
we dont really know, but they appear during the window of implantation, so may assist in adhesion
when is the window of implantation
typically starts on day 21
list the major uterine blood vessels
- uterine artery
- arcuate arteries
- radial arteries
- spiral arteries
what is special about the spiral arteries?
they are tonically active
what happens to the spiral arteries during menses?
they lose their terminal segments. to prevent exsanguination, they spasm
- this causes cramps
what happens to the spiral arteries during the proliferative phase?
they grow back very rapidly, so rapidly that they grow faster than the endometrium and form spring like coils
how do we know the decidual reactions are not required for implantaiton?
ectopic pregnancies
what are the (technically three) layers of the cervix and their epithelia?
- endocervix (single columnar)
- transitional zone
- ectocervix (multi-layered squamous)
cervical cancers always arise in the?
transitional zone of the cervix
when does the transitional zone form?
puberty
describe the epithelia changes before puberty in the cervix between zones
they change in the space of a single cell (from simple columnar to multi-layered squamous)
which vaccination/disease effects the transitional zone?
HPV
