Other Control Mechanisms
		Direct hypothalamic control – stimulation of the adrenal medulla to secrete epinephrine.
	Substrate control – direct response by glands. •  parathyroid glands – secrete PTH (parathyroid    hormone) in response to i blood calcium •  thyroid parafollicular cells (C cells) – secrete    calcitonin in children, respond toh blood calcium • Pancreas – a and b Islet cells secrete glucagon and insulin, in response to plasma glucose.