Reproductive Endocrinology Pt 1 Flashcards
Two cell types in ovary?
Germ cells (Oocyte)
Somatic cells
The two Ovarian functions?
Gametogenesis: oogenesis and folliculogenesis
Steroidogenesis: production of hormones such as oestrogens and progesterone
What is oogenesis?
Differentiation of the ovum into a cell competent to further develop when fertilized
Oogonia divide by meiosis during foetus
What is folliculogenesis?
A developing oocyte surrounded by layers and eventually released during ovulation
If not fertilised then becomes corpus luteum, and albicans later
Order of HPG axis hormones
FSH
Oestrogens
Then LH
What is steroidogenesis? And what does it lead to?
All follicles what FSH to release so they send oestrogen to hypothalamus to form Graafian follicles for ovulation
Once corpus luteum forms from Graafian follicle, it secretes progesterone
What does progesterone do post ovulation?
Exert negative feedback stopping further follicle growth
What are the two options after ovulation?
Fertilisation:Corpus luteum maintained by hCG
No fertilisation:Corpus Luteum dies after two weeks prog and oestrogen levels fall and goes back to step one allowing release of Gnotrophin again
What is the seminiferous tubules and what type of cells are found there/function?
Site of sperm production
Sertoli cells: aid in synthesis of sperm
Leydig cells: Produce testosterone
N.B. -Germ cells are basically stem cells that develop into things like spermatogonium which develop into sperm.
Which way does spermatogenesis work towards?
Moves inwards towards the lumen where final sperm can be transported
What are the two main testicular functions?
Gametogenesis:spermatogenesis
Steroidogenesis: Production of hormone testosterone
Facts about spermatogenesis
-200-300mill of sperm daily
-Optimal temp is 2 degrees lower than core temp
-Duration:74 days
-Decrease in quality occurs after 35 years old
-Lifestyle affects sperm like smoking damages sperm DNA
-Trauma/Cancer
Spermatocytogenesis steps explained
Meiosis splits it from 1 diploid spermatocyte to 4 haploid spermatids
(Occurs in testis after puberty)
Spermatocytogenesis first then spermiogenesis, anyway what’s the four steps of spermiogenesis?
1.Golgi phase: DNA PACKING
2.Cap phase: acrosome formation
3.Tail phase: elongation of microtubules
4.Maturation phase: removing residual cytoplasm and organelles via phagocytosis
Explain functions of Epididymus
1.Storage- Sertoli cells secrete testicular fluid
Sperm reach the epididymus and stored till ejaculation
- Sperm motility - mature immotile sperm acquiring motility function
What cells secrete testosterone
Leydig cells
