Folliculogenesis, Oogenesis and Ovulation Flashcards
What is folliculogenesis?
Development of ovarian follicles eligible for ovulation
What is Oogenesis?
development of primary egg cell into mature ovum able for fertilisation
What are the two stages of Oogenesis?
-prenatal
- after puberty (during each cycle)
What development occurs before nuclear arrest in oogenesis?
- primordial germ cell - (mitosis) - oogonia
- oogonia - (mitosis) - primary oocyte
- primary oocyte - (meiosis- prophase 1)
When does meiosis resume after nuclear arrest of Oogenesis?
-LH surge (preovulatory)
- this resumes meiosis causing a secondary oocyte
What are the four stages of Oocyte maturation?
- prenatal mitotic divisions
- nuclear arrest
-cytoplasmic growth - resumption of meiosis
What is the fist stage of folliculargenesis?
PRIMORDIAL FOLLICLE
- flattened granulosa cells
-contains a primary oocyte
How do the granulosa cells develop in a primary follicle?
- cuboidal rather then flattened
What is the structure of the secondar follicle in the folluculargenisis process?
- 3 granulosa cell layers
- small number of theca cells
- development of the zona pellucida (matrix surrounding oocyte)
What is the structure of the tertiary follicle at folliculargenisis?
- develops an antrum ( space between granulosa cells)
-Theca cells increase to have an externa and internal layers around the outside
-follicular fluid is contained
What is the structure of a preovulatory follicule during folliculargenisis?
-antrum develops
-mature
What stages of folliculargenisis require gonadotrophic hormones?
-tertiary follicule
-preovulatory follicule
What stages of folliculargenisis occur prenatally?
- oogonia
- primordial follicle
- primary follicle
What do growing follicles secrete?
Oestradiol
What is atresia?
Degeneration of a follicle
can occur if not selected at any stage of growth before generating into a ovulatory follicle
