Reproductive Endocrinology Flashcards
Name the earliest recognisable germ cell.
Primordial germ cell
2 polar bodies in the germ cell signifies what?
sperm entry and the completion of the 2nd meiotic division
In what phase of the ovarian cycle are oestrogen and progesterone secreted in? What is the signficance of their secretion?
Oestrogen - Follicular phase
Progesterone - Luteal phase
essential for preparation of uterine lining for implantation
Degeneration of corpus luteum signals what? What does it degenerate to?
Start of a new follicular phase - fertilisation did not occur
Degenerates to the corpus albicans
If fertilisation has occured what does the corpus leuteum do?
Corpus luteum persists and produces increasing quantities of progesterone and oestrogen until after pregnancy
What does the hypothalamus secrete that acts on the anterior pituitary to produce hormones?
GnRh
Gonadotrophin releasing hormone
What does the anterior pituitary release?
FSH LH GH ACTH TSH
What does the posterior lobe of the pituitary gland secrete?
ADH
Oxytocin
What separates the hypothalamus in two?
The 3rd ventricle
When GnRH acts on the anterior pituitary which hormones are released?
FSH - follicle stimulating hormone
LH - lutenizing hormone
What is the function of FSH?
Acts on ovary
Stimulates development of follicles
What is the function of LH?
Acts on ovary
Stimulates follicle maturation, ovulation and development of the corpus luteum
FSH and LH stimulate the secretion of what and stimulate what?
Oestradiol and stimulate ovulation
What is the function of the theca cells?
Produce androgen which is converted by the granulosa (aromatase) to oestradiol
What is the function of oestradiol?
Thickens endometrium
Thins cervical mucus
Oestrogen does what to the FSH production by the anterior pituitary? What does this do?
Suppresses it
Allows the selection of dominant follicle
The high levels of oestrogen at mid cycle cause what?
Cause the hypothalamus to release GnRH
Causes a surge in release of FSH and LH from the anterior pituitary
After ovulation what happens to the levels of LH and FSH?
Decrease
If fertilisation occurs, what does the developing embryo produce? What are their functions?
hCG (chorionic gonadotrphin) - Functions to maintain the corpus luteum
Progesterone - functions to support pregnancy and suppress ovulation
When does the placenta take over the role of producing progesterone and what happens to the corpus luteum?
6 weeks
Corpus luteum degenerate to the corpus albicans
Which hormones stimulate spermatogenesis?
FSH and testosteroe
Which hormone stimulates testosterone secretion?
LH
What decreses secretion of FSH?
Inhibin
Testosterone does what to the releasing of GnRH and LH?
Decreases it - negative feedback
