Final answer:
Hormone production is initiated by a specific stimulus, which can act through the hypothalamus or the nervous system. The hypothalamus releases release factors that stimulate the pituitary gland to produce tropic hormones, which then stimulate other endocrine glands to produce specific hormones.
Step-by-step explanation:
The production of hormones can be initiated by a specific stimulus, which can act firstly in the hypothalamus or via the nervous system (known as neural potential).
The hypothalamus, which is part of the central nervous system, releases 'release factors' that travel through the hypophyseal-hypothalamic portal vein to the pituitary gland.
The pituitary gland then produces the respective tropic hormone, which stimulates another endocrine gland to produce the specific hormone required for the physiological response.