Final answer:
The gland that initiates puberty is the hypothalamus, which triggers the pituitary gland to secrete hormones targeting the gonads, leading to the production of testosterone in boys and estrogen in girls, which in turn promote the physical changes associated with puberty.
Step-by-step explanation:
Which Gland Initiates the Process of Puberty?
The process of puberty begins with the hypothalamus, which releases pulses of gonadotropin-releasing hormone (GnRH). This, in turn, signals the pituitary gland to secrete hormones like follicle-stimulating hormone (FSH) and luteinizing hormone (LH). These hormones target the gonads, which are the testes in boys and the ovaries in girls. In boys, LH stimulates the testes to secrete testosterone, which promotes growth and the development of secondary sexual characteristics such as increased muscle mass, the growth of facial hair, and deepening of the voice. In girls, FSH and LH stimulate the ovaries to produce estrogen, which causes physical changes such as the widening of hips, development of breasts, and the start of the menstrual cycle.