Repro Part 2 Females Flashcards
How are primary oocytes produced during fetal life?
Primordial germ cells undergo mitosis to form oogonia. Oogonia start meiosis I and stops, becoming primary oocytes.
How many oocytes remain at birth and puberty?
At birth, ~1-2 million primary oocytes remain. By puberty, only about 300,000 remain.
What happens to a primary oocyte during puberty every 28 days?
completes meiosis I, becoming a secondary oocyte.
What happens to the secondary oocyte during ovulation?
The secondary oocyte is released at ovulation and completes meiosis II only if fertilized.
How does oogenesis differ from spermatogenesis?
Oogenesis involves asymmetric division, limited oocyte production, and ends at menopause, whereas spermatogenesis is continuous.
What happens during the follicular phase of the ovarian cycle?
Primordial follicles develop into primary follicles, some become secondary follicles, and a dominant tertiary follicle forms before ovulation.
What are the three phases of the uterine cycle?
- Menses (shedding)
- Proliferative phase (endometrial thickening)
- Secretory phase (glands secrete fluids).
What occurs during the luteal phase of the ovarian cycle?
After ovulation, the corpus luteum forms and secretes progesterone and estrogen. If fertilization doesn’t occur, it degenerates into the corpus albicans.
How is the menstrual cycle regulated in the early follicular phase?
LH stimulates androgens, FSH converts them to estrogen in granulosa cells, and estrogen exerts negative feedback to shut down FSH and LH.
What triggers the LH surge during the menstrual cycle and what does it trigger?
High estrogen levels cause positive feedback at the hypothalamus, leading to an LH surge that triggers ovulation.
What are the reproductive factors for a woman of older age?
The number of follicles declines
oocyte quality decreases
after menopause, estrogen and progesterone fall, while FSH/LH levels rise.
