Female Reproduction Physiology Flashcards
Function of the ovaries
Oocyte production - One mature egg per menstrual cycle, 400 over entire lifespan. Rapid decline at 30-40 y/o
Steroid hormone production
What steroid hormones do the ovaries produce and what are their purposes?
oestrogen - secondary sexual characteristics (breast, hair, etc)
progesterone - endometrium for implantation
testosterone - maintain sexual function
What is the development of the oocytes before puberty?
There is mitotic cell division of ooogonium to form pri oocytes. These pri oocytes develop primordial follicles.
This process is then arrested in the first stage of meiotic division.
What hormone stimulates the continuation of oocyte development?
FSH and LH
What is the development of the oocytes after puberty?
The first meiotic division ends and the second division starts.
This means that a secondary oocyte, capable of being fertilised, is released during a menstrual cycle.
The second meiotic division finishes after the oocyte is fertilised by the sperm.
What are the different stages in oogenesis and what is their chromosome content (in ‘n’ terms)?
Oogonium 2n
Primary oocyte 2n
Secondary 1n
Fertilised 2n
What is the process from oogonium to primary ooctye?
Mitosis
What is the process from primary oocyte to secondary ooctye?
Meiosis I. Note the discarding of a polar body.
What is the process from secondary oocyte to ovum?
Fertilisation, which allows for Meiosis II to happen. Note the discarding of a polar body here too.
For your ease: your version of events of oogenesis part 1.
We start as a ball of cells. The ball of cells are obviously 2n. Some cells are destined to become the set 400 egg cells. They are the oogonium.
The oogonium has to make 400 of itself, each with 2n. It does this via mitosis. Each of these is then the primary oocyte (2n).
For your ease: your version of events of oogenesis part 2.
The primary oocyte starts undergoing meiosis but your body is like ‘pls stop you’re not even ready to be fertilised ya nasty’.
So when you’ve hit puberty, you’re ready to be nasty. FSH + LH let meiosis I continue. Primary oocyte becomes secondary oocyte (1n) + polar body (discarded).
For your ease: your version of events of oogenesis part 3.
If the nasty works, you get fertilisation. Meiosis II then continues. You end up with the fertilised egg (2n) + polar body (discarded).
So mitosis is from oogonium to pri oocyte. Meiosis I is from pri oocye to sec oocyte (+ polar body). Meiosis II is sec oocyte after fertilsation (+ polar body).
