The correct option is A is true but R is false
Explanation
The regulation of reproductive functions is governed by the Hypothalamus-Pituitary-Gonadal (HPG) axis, involving specific signaling pathways between the hypothalamus and the pituitary gland.
Analysis of Assertion (A):
Correct. Gonadotrophin-releasing hormone (GnRH) is a peptide hormone synthesized and secreted by the hypothalamus. It travels through the hypophyseal portal system to the anterior pituitary gland (adenohypophysis). Upon reaching the anterior pituitary, GnRH binds to specific receptors on gonadotroph cells, stimulating the synthesis and release of gonadotrophins, namely Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH).
Analysis of Reason (R):
Incorrect. Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH) are synthesized and secreted directly by the anterior pituitary gland, not the hypothalamus. The hypothalamus produces releasing hormones (like GnRH) and inhibiting hormones. While the posterior pituitary stores hormones produced by the hypothalamus (such as Oxytocin and Vasopressin), the anterior pituitary produces its own hormones.
Key Takeaway:
The hypothalamus produces GnRH, which acts as a releasing factor. The anterior pituitary responds to GnRH by synthesizing and secreting the gonadotrophins LH and FSH.