A young woman enters pubey with approximately 40,000 primary oocytes in her ovary. About how many of these primary oocytes will be ovulated over the entire reproductive life of the woman
**Core Concept**
The question tests the understanding of the number of primary oocytes present in the ovaries at birth and the process of follicular development, ovulation, and atresia. The ovarian reserve is critical in gynecology and reproductive medicine, affecting fertility and menstrual cycle regulation.
**Why the Correct Answer is Right**
At birth, a female has approximately 1-2 million primordial follicles containing primary oocytes. However, only about 400-500 of these follicles will mature and ovulate over the woman's lifetime. This limited number is due to the continuous process of follicular atresia, where most follicles degenerate and disappear. The remaining follicles are selected for further development, and only a few reach maturity, leading to ovulation.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it suggests a significantly higher number of primary oocytes will be ovulated, which contradicts the established understanding of ovarian reserve and follicular atresia.
**Option B:** This option is incorrect because it suggests a lower number of primary oocytes will be ovulated, which is not supported by the available data on ovarian reserve and follicular development.
**Option C:** This option is incorrect because it suggests a number of ovulated primary oocytes that is not consistent with the estimated number of primordial follicles present at birth and the rate of follicular atresia.
**Clinical Pearl / High-Yield Fact**
A key concept to remember is that the number of primary oocytes present at birth is finite, and the process of follicular atresia significantly reduces the number of follicles that will mature and ovulate over a woman's lifetime. This understanding has important implications for fertility preservation and reproductive medicine.
**Correct Answer:** C. 400-500.