Female reproductive Flashcards
What are the two main functions of the ovary?
Produce haploid gametes capable of being fertilized
Produce sex hormones: oestrogen progesterone, and peptides (e.g. inhibin, activin) which act both systemically and locally.
When does meiosis of gametes occur in females?
Starts and arrests in foetal life
After birth what slowly happens to the follicles?
Atresia (apoptosis)
How many primary oocytes are produced?
6-7million
How many oocytes does a woman ovulate in her lifetime?
~400
What does a follicle consist of?
Primary oocyte, surrounded by its zona pellucida, granulosa cells and later, thecal cells
What substance surrounds the primary oocyte?
Zona pellucida - glycoprotein
What does interstitial tissue of ovary contain?
Corpora lutea and corpora albicantia from previously ovulated follicles/ matter from atretic follicles
Connective tissue, vessels and nerves.
What junctions link granulosa cells?
Gap junctions
How many layers of the thecal cells surround a follicle?
2, inner theca interna and outer theca externa
What is the role of the theca interna cells?
Secrete androgens
What is the role of the theca externa?
Protective capsule
After the primary oocyte leaves the follicle in ovulation, what forms the corpus luteum?
Granulosa and theca interna cells
When is day 1 of the menstrual cycle?
The first day of menstruation
How many days does the menstrual cycle last?
~28 days
What determines length of the menstrual cycle?
Follicle growth and corpus luteum lifespan
What are the two phases of the menstrual cycle and why are they named as such?
During the first half the reproductive system is dominated by a developing follicle (follicular phase)
After ovulation products of the corpus luteum dominate (luteal phase).
What triggers puberty?
Activation of kisspeptin neurones
What does kisspeptin activation stimulate?
Release of hypothalamic GnRH
What does GnRH stimulate?
Release of FSH and LH from the anterior pituitary
When to primordial follicles appear?
16-24 weeks gestation
What are the layers of the primordial follicle?
Primary oocyte surrounded by a single layer of flat pregranulosa cells
What happens in the initial stage of follicle development?
Primary oocyte enlarges and the granulosa cells become rounded to produce a primary follicle
What does a primordial follicle develop into?
Primary follicle