Oogenesis Flashcards
What is oogenesis?
the process of maturation and differentiation of primordial germ cells to oogonia to primary oocytes then secondary oocytes (ova)
Where does oogenesis occur?
in the ovarian cortex
The 4 peculiarities of oogenesis are …
- Starts before birth (5th month in utero)
- Suspended in the middle (birth to puberty)
- Restarts at puberty (9-13 years)
- Continues up until menopause (45-55 years)
What are the major processes of oogenesis?
- Mitosis of ovarian follicular cells
2. Meiosis of the oocyte.
How do the processes of oogenesis occur?
In tandem
What are the 4 detailed processes of oogenesis?
- Growth of follicles in size
- Differentiation of follicular cells to produce hormones.
- There’s a concurrent development of endometrium
- Cyclic occurrence (ovarian or menstrual cycle)
What stage are oocytes and where can they be found before puberty?
They are primary and housed in primordial follicles.
What stage are primary oocytes suspended in?
The dictyotene stage of Meiosis 1
How many follicles are stimulated to mature at puberty?
5-20
What occurs to stimulate follicular maturation?
FSH inhibits oocyte maturation inhibitor (OMI)
How long does it take a primary oocyte to complete the first meiotic division?
Within 1 hour of ovulation
What causes the mature follicle to rapture and discharge secondary oocyte(ovum) from the ovary?
Influence of a surge in Luteinizing hormone (LH)
What happens to the secondary oocyte after it is discharged from the ovary?
It is sucked into the fallopian tube
When does the 2nd meiotic division occur?
Only after the ovum has been fertilized by a spermatozoon
