Final answer:
The adrenal medulla consists of chromaffin cells which interact with preganglionic fibers of the sympathetic division, not parasympathetic, of the autonomic nervous system, releasing epinephrine and norepinephrine into the blood.
Step-by-step explanation:
The cells of the adrenal medulla are actually closely associated with the preganglionic fibers of the sympathetic division of the autonomic nervous system, not the parasympathetic division. These preganglionic sympathetic fibers stimulate the adrenal medulla to secrete the catecholamines, epinephrine and norepinephrine. The adrenal medulla functions as a part of the sympathomimedullary pathway (SAM) pathway, adapting the body to stress by increasing heart rate, blood pressure, and energy supplies.
Moreover, the cells within the adrenal medulla, called chromaffin cells, are neurosecretory cells that release these hormones directly into the bloodstream, acting as a functional sympathetic ganglion. Their unique feature is that instead of synapsing with postganglionic neurons, they release their neurotransmitters directly into the blood, functioning as part of the endocrine system and sympathetic nervous system.