Lecture 25 Flashcards
What are the component parts of the female reproductive system?
Ovary
Uterine tubes
Uterus
Cervix and vagina
What is the function of the ovary?
Center of cyclicity - ovary manages menstrual cycle - driven by pituitary gland - controlled by nuclei in hypothalamus Oocytes Sex steroids (estrogen, progesterone)
What is the function of the uterine tubes?
Tube that comes off of uterus
Site of fertilization (ampulla)
Gamete transport
- egg and sperm move in opposite directions
What is the function of the uterus?
Embryo and fetal growth
Placentation
What is the function of the cervix and vagina?
Expulsion of infant
Capacitation of sperm
Mucus in cervix
Where are the ovaries located?
On either side of midline
How does the uterine tube look?
Curves around seashape
What are structural features of the ovary?
Double layered broad ligament
- Holds uterine tubes in place
Fimbriated bit (funnel shaped) extend over ovary and infendibulum (hollow stalk that connects hypothalamus and pituitary gland)
What happens to the ovaries during ovulation?
Ovary becomes bright red
- egg is trapped by funnel when going down uterine tube
(sometimes egg can go up into abdominal cavity then degenerates)
What is ectopic fertilization?
Egg can go to the wrong place or sperm can go out of uterine tube and implants in the wrong place Nowhere else can support implantation - begin to grow to get blood supply - tears off - fatal
What is placenta previa?
When the embryo implants in the bottom part of the uterus and blocks the canal root
How does the endometrium grow?
From increase of progesterone then shrinks from decrease (menstruation)
What is the main ligament in the ovary?
Round ligaments
What is ovarian asymmetry?
When one ovary is active during menstruation
What is Hyperemia?
Good blood supply Red swells (non-ovulating is pale)
How does estrogen affect the ovary?
Rapid mitosis
How does progesterone affect the ovary?
Secretory aspects
What are two stages of menstruation?
- Pre-ovulatory (estrogenic phase)
- more variable - Post-ovulatory (progesteronic phase)
- more stable
- when implantation occurs
What is the ovarian follicle?
Cellular sac in which oocyte matues in response to FSH and LH
What do follicles produce?
Hormones and egg
(same hormones in males and females but different function)
FSH affects follicles, LH affects follicles to burst open and release egg
What can primordial follicles do?
Contain egg with glassy layer Start to develop three months layer - storage - primed for development - undergo development[ - - Under influence of FSH, start to grow
What do primordial follicles become next?
Primary follicles
- sac of cells surrounding egg become cuboidal from squamous
Egg doesn’t grow much but sac does
- more layers of cells in a secondary follicle
What do secondary follicles develop into?
Develops cavities
What do cavities do?
Coalesce do become one big cavity Corona radiata (layer of cells) extend around follicle Gap of fluid (cavity)
What is stigma?
When the follicle starts to ovulate then bulges out
How does LH affect menstruation?
Eggs pop out then goes down uterine tube
What happens when the shell of follicle collapses on itself?
Seals itself
Forms Corpus luteum
Produces progesterone
If no signal of pregnancy, menstruation causes corpus albicans
What is corpus albicans?
Scar formed from follicles that burst out and ovulated (more scars as menstruation occurs)
What happens to progesterone production when pregnancy occurs?
continues to be produced
FSH initially drops then rises after ovulation. Why?
Stimulates ovaries to release estrogen
Estrogen levels rise as follicles become larger
Estrogen feedback to Arcuate nucleus as it starts to rise
- cause burst of activity in LH
- LH reaches peak (18-24 hours before ovulation)
- trigger ovulation
- -can measure LH in urine
- - egg will be ready to be collected when LH reaches peak
- - useful for IVF
What happens to the lining of uterus as estrogen levels rise?
Becomes thicker
Why do breasts enlarge during menstruation?
breast duct expands
how can estrogen cause breast cancer?
Stimulates mitosis (can treat 50% of cancers by blocking estrogen receptor)
- especially in menopausal women
- early menarchy, late menopause and lack of offspring leads to more exposure to estrogen
(higher risk)
Lactating reduces risk of breast cancer as it reduces estrogen level
What produces progesterone?
Follicle regression
If no pregnancy after 10days,…?
Progesterone levels drop - triggers loss of lining of uterus, and menses
What is atresia?
Natural process of cell death that destroys follicles at cell stages of development
What is follicle dominance?
One follicle becomes dominant at day 9
Dominant follicle can be seen in ultrasound (bigger than the rest)
Suppresses other follicles by inhibin (very rarely can ovulate two but usually just one)
What is a sign of polycystic ovarian syndrome (PCD)?
When many small follicles develop instead of one dominant one
- surprisingly common
- can kill itself; can have it all their lives, can be treated (by contraceptive pill)
What are symptoms of PCD?
Increase in weight
hair (estrogen is converted to testosterone)
What molecule is looked for in a pregnancy test?
hCG
When can a spontaneous abortion (miscarriage) occur?
If corpus luteum degenerates too quickly
What role does the placenta have?
When developed enough, can take over the role of hormonally supporting the placenta. Transition from corpus luteum to placenta support is a critical time…
