FSH is secreted by
**Core Concept**
FSH (Follicle-Stimulating Hormone) is a crucial hormone in the reproductive axis, primarily involved in the regulation of the development and maturation of ovarian follicles in females and spermatogenesis in males. It is a glycoprotein hormone produced by the pituitary gland.
**Why the Correct Answer is Right**
FSH is secreted by the anterior pituitary gland, specifically by the gonadotrope cells. The production of FSH is stimulated by Gonadotropin-Releasing Hormone (GnRH) from the hypothalamus, which acts on the pituitary gland to release FSH and Luteinizing Hormone (LH). The FSH molecule binds to its receptor on the surface of the ovarian follicles, promoting follicular growth and development.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because FSH is not secreted by the adrenal glands, which primarily produce hormones such as cortisol and aldosterone.
**Option B:** This option is incorrect because FSH is not secreted by the thyroid gland, which produces hormones such as thyroxine (T4) and triiodothyronine (T3).
**Option C:** This option is incorrect because FSH is not secreted by the pancreas, which produces hormones such as insulin and glucagon.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that FSH levels can be used as a marker for ovarian reserve in females, with elevated levels indicating a decreased ovarian reserve and potential fertility issues.
**Correct Answer: C. The anterior pituitary gland.**