structure of ovary and follicle Flashcards
Which artery do the ovarian arteries branch off of?
At what level?
–abdominal aorta at the level of the renal arteries
between which vessels are there anastomoses?
Where do the uterine and vaginal arteries originate from?
What’s the physiological consequence of the anastomoses?
uterine artery and vaginal artery
internal iliac
enables coordination of physiological and histological changes in menstrual cycle
Where would you find the oogoniaa?
What is the medulla an embryonic remnant of?
What cells are present in the cortex? In the medulla?
Cortex
Wolffian duct
cortex - stromal cells, gametes
medulla - stromal cells, mesenchymal cells
Development of follicles
At what stage does it stop until puberty?
primordial follicle
What 3 cell types are present in the cortex?
What happens to the PGC?
What happens to the stromal cells?
- epithelial cell lining
- stromal cells
- PGCs, oogonia
PCGs - mitotic division
stromal cells - proliferate and cluster around oogonia
What happens to the oogonia during the 2nd trimester?
What stage of meiosis do they freeze at? What is the oogonia now called?
-cease mitotic division, increase in size and enter 1st meiotic division
remain at prophase
now called primary oocytes
Describe atresia
degeneration or germ cell loss
What are primordial follicles made of?
What are the granulosa cells?
What will the stromal cells do later to the primordial follicle?
single layer of granulosa cells surrounding primary oocyte
- mesenchymal cells
- do the second wrap
What are LH and FSH responsible for in the female?
FSH – development and maturation of oocytes
LH – ovulation and lutenization, and progesterone production
In the menstrual cycle, when do FSH and LH peak?
When does progesterone start being at high levels?
Oestradiol – How does the release of LH affect it?
at ovulation
after LH surge (after ovulation) and luteal phase
cause small drop in oestradiol
What’s the hormone that triggers the 2nd half of the development of oocytes?
When does this start from? (at what stage of life)
- high FSH
- primary follicles
When the hormone FSH is released, how many primordial follicles ‘wake up’?
What changes do they undergo?
Between what cells does the zona pellucida form?
30-40
enlargement of oocyte
proliferation granulosa cells (cuboidal)
multilayering of granulosa cells
formation of zona pellucida
What’s the significance of the zona pellucida?
What are the gap junctions? What do they allow?
What maintains the meiotic arrest of the oocyte?
- protection and avoidance of polyspermy
- allow passage of nutrients
- cAMP
What happens when the follicle becomes a secondary follicle?
What do the ^ contain?
What are the 2 layers formed by stromal cells?
What is secreted by the 2 layers(^)? What’s secreted by the granulosa cells?
granulosa cells proliferate
antral cavities rich in hyaluronic acid appear
stromal cells condense = theca interna and externa
thecal cells produce androgens
granulosa cells produce oestrogen
At the tertiary follicle stage: What happens to all the antral cavities?
What’s the cumulus oophorus?
What happens to oestrogen?
What receptors are starting to be expressed on Granulosa cells?
–form a large antrum
–oocyte is separated from follicle fluid by granulosa cells
–increase in oestrogen secretion
–LH receptors
What triggers a surge of LH in the pre-ovulatory follicle?
What does LH do?
At what stage is meiosis arrested in at the stage of pre-ovulatory follicle?
When the oocyte breaks free from the follicle wall, what does it take with it? Where does it go?
Pain and bleeding may occur T/F?
–increased oestrogen
–induces Oocyte to come out of arrest and complete meiosis
–Haploid gamete (secondary oocyte) and a small polar body (first polar body) at metaphase II
–some granulosa cells at goes to peritoneal cavity = corona radiata
TRUE
After expulsion of the oocyte, what happens to the follicle?
What hormone(s) are being produced?
What is lutenization?
the remaining follicle is called the corpus luteum
LH and progesterone
granulosa cells which fill up with yellow lipid
If not fertilisation occurs, what happens to the corpus luteum?
What hormone level drops to signal the next menstrual cycle?
In what circumstances would the CL persist? Why?
becomes an acellular corpus albicans (10-12 days)
progesterone
A second LH surge is required to extend the life of corpus luteum and this occurs in pregnancy.
If fertilisation occurs, what hormone is produced?
What does this hormone do?
By what month does the uterus take over the CL of pregnancy’s job?
hCG
signals ant pit to produce LH
fourth month of pregnancy
What layer of the endometrium is shed during mensturation? What replaces it?
stratum functionale
stratum basale
In relation to the oocyte, when does the proliferative and secretory phases of the endometrium occur?
7-24 days?
How would you distinguish the proliferative phase of the endometrium histologically?
What 3 things does oestrogen stimulate in the endometrium?
What is the stratum functionale rich in?
tubular cross sections - proliferative phase
- mitotic activity
- increases thickness
- increase length of spiral aa
uterine glands and blood vessels
Histologically, what happens to the uterine glands?
What hormone is responsible?
white glands
progesterone
What’s present on surface epithelial cells. What also happens to them?
Secretory phase is the best time for implantation T/F?
How long is the implantation window?
microvilli and negative charge
surface change to attach egg
FALSE - receptive phase
5-7 days
By what process is the functional endometrium stripped off?
Degradation of the CL – what 2 hormones are shut off?
degeneration of corpus luteum
progesterone and oestrogen
What is amenorrhoea? Menorrhagia? Dysmenorrhoea? Post-menopausal bleeding?
Amenorrhoea – absence of menstruation.
Menorrhagia – excessive bleeding
Dysmenorrhoea – excessive pain-
Post-menopausal bleeding- important symptom of malignant disease
