342x342px The<unk>  is a physiological connection between the sympathetic nervous system and the adrenal medulla and is crucial in an organism's physiological response to outside stimuli. When the body receives sensory information, the sympathetic nervous system sends a signal to preganglionic nerve fibers, which activate the adrenal medulla through acetylcholine. Once activated, norepinephrine and epinephrine are released directly into the blood by postganglionic nerve fibers where they act as the bodily mechanism for "fight-or-flight" responses. Because of this, the<unk>  plays a large role in maintaining glucose levels, sodium levels, blood pressure, and various other metabolic pathways that couple with bodily responses to the environment. During numerous diseased states, such as hypoglycemia or even stress, the body's metabolic processes are skewed. The<unk>  works to return the body to homeostasis through the activation or inactivation of the adrenal gland. However, more severe disorders of the<unk>  such as Pheochromocytoma (a tumor on the adrenal medulla) can affect the body's ability to maintain a homeostatic state. In these cases, curative agents such as adrenergic agonists and antagonists are used to modify epinephrine and norepinephrine levels released by the adrenal medulla.
Sympathoadrenal system
Hypothalamic–pituitary–adrenal axis
Hypothalamic–pituitary–somatotropic axis
Hypothalamic–pituitary–thyroid axis
Parasympathetic nervous system
Hypothalamic–pituitary–gonadal axis
Autonomic nervous system
Hypothalamic–pituitary–prolactin axis