Which of the following pubeal events in girls is not oestrogen dependent?
**Core Concept**
Oestrogen plays a crucial role in the pubertal development of girls, influencing the growth and maturation of various bodily systems. The pubertal events in girls are primarily driven by the increasing levels of oestrogen, which is produced by the ovaries.
**Why the Correct Answer is Right**
The growth of the uterus and vagina is not solely dependent on oestrogen. While oestrogen stimulates the growth of these organs, the proliferation and thickening of the vaginal epithelium are also influenced by the local production of oestrogen. However, the growth of the uterus is primarily driven by the growth hormone and the ovarian hormones in general, but the uterus is more influenced by the **Progesterone** (not listed) which is also involved in the menstrual cycle. But in the context of the given options, the correct answer is the one that is least dependent on oestrogen.
**Why Each Wrong Option is Incorrect**
* **Option A:** is incorrect because breast development is primarily driven by oestrogen, which stimulates the growth of breast tissue.
* **Option B:** is incorrect because the growth of pubic hair is influenced by the increase in androgens, which are produced in response to the increasing levels of oestrogen.
* **Option D:** is incorrect because the development of the clitoris is influenced by the growth hormone and oestrogen.
**Clinical Pearl / High-Yield Fact**
The timing and progression of pubertal events can vary widely among girls, and the presence of oestrogen is essential for the development of secondary sexual characteristics.
**Correct Answer: C.**