Oogenesis and Spermatogenesis Flashcards
When does oogenesis cease?
Menopause
Earliest recognisable germinal cell
Capable of mitosis
Migrate to genital ridge by week 6 of embryo development
Primordial germ cell
Completion of last pre-meitoic division forms what?
Oocytes
Presence of what signifies sperm entry and the completion of 2nd meiotic division?
2 polar bodies
In which phase does the egg mature and become ready for ovulation
Follicular phase
What signals the end of the follicular phase?
Ovulation
Which phase induces preparation of reproductive tract for pregnancy?
(if fertilisation occurs)
Luteal phase
The primary oocyte is surrounded by a layer of which type of cell?
Granulosa cells
-This is called the primary follicle
What helps the follicle to differentiate?
Hormonal influence
What happens to follicular cells left behind after ovulation?
They undergo luteinisation and transform into the corpus luteum
Which hormone is essential for preparation of uterine lining for implantation?
Progesterone (secreted in luteal phase)
How many days does the corpus luteum grow for?
8-9 days
if no fertilisation has occured, it wil survive no longer than 14 days after ovulation
What signals the start of a new follicular phase?
Degeneration of the corpus luteum
Which hormone stimulates secretion of oestradiol and ovulation?
FSH and LH
Which hormone stimulates follicle maturation, ovulation and development of corpeus luteum?
LH
These cells produce androgen which is converted by the granulosa to oestradiol
Theca cells
What does oestradiol do to the endometrium and cervical mucus?
Thickens endometrium and thins cervical mucus
Which hormone supresses FSH production
Oestrogen
Granulosa in the dominant follicle expresses what receptor?
LH receptor
High levels of what hormone at mid cycle cause hypothalamus to release GnRH?
Oestrogen
-causes FSH and LH surge from anterior pituitary
When does the follicular fluid and number of granulosa increase?
Ovulation
When does the cumulus oophorus loosen?
Ovulation
What does the corpeus luteum degenerate into?
Forms the corpus albicans
if there is no hCG production by 12 days the corpus luteum degenerates etc…
Which hormone maintains the corpus luteum?
hCG
Produces progesterone to support pregnancy and suppress ovulation
-Around 6 weeks the placenta takes over this role and the corpus luteum degenerates forming the corpus albicans
Hormone that stimulates testosterone secretion?
LH
testosterone decreases release of GnRH and LH
Which hormones stimulate spermatogenesis?
FSH and testosterone
Which hormone decreases secretion of FHS?
Inhibin
What do sertoli cell produce?
ABG (androgen binding globulin)
and Inhibin
(sertoli cells found in seminiferous tubule)
When is surgical sperm aspiration indicated?
Azoospermia
