Answer:
The hypothalamus; gonadotropin-releasing hormone (GnRH) begins to increase its production of pituitary; follicle-stimulating hormone (FSH) to initiate puberty which actually occurs in middle childhood at least a year or two before even the earliest bodily changes of puberty.
Step-by-step explanation:
Puberty is initiated by gonadotropin releasing hormone (GnRH) produced and secreted by the hypothalamus. The GnRH acts on the pituitary gland to produce and release follicle stimulating and luteinizing hormone (LH) which travel through the blood to the testicles and ovaries to initiate the process of sexual maturation.