Question: What hormone produced by both the adrenal glands and certain neurons is released by chromaffin cells?

<P0-S0> Neuroendocrine cells are cells that receive neuronal input (neurotransmitters released by nerve cells or neurosecretory cells) and, as a consequence of this input, release message molecules (hormones) to the blood. <P0-S1>  In this way they bring about an integration between the nervous system and the endocrine system, a process known as neuroendocrine integration. <P0-S2>  An example of a neuroendocrine cell is a cell of the adrenal medulla (innermost part of the adrenal gland), which releases adrenaline to the blood. <P0-S3>  The adrenal medullary cells are controlled by the sympathetic division of the autonomic nervous system. <P0-S4>  These cells are modified postganglionic neurons. Autonomic nerve fibers lead directly to them from the central nervous system. <P0-S5>  The adrenal medullary hormones are kept in vesicles much in the same way neurotransmitters are kept in neuronal vesicles. <P0-S6>  Hormonal effects can last up to ten times longer than those of neurotransmitters. <P0-S7>  Sympathetic nerve fiber impulses stimulate the release of adrenal medullary hormones. <P0-S8>  In this way the sympathetic division of the autonomic nervous system and the medullary secretions function together. <SEP> <P1-S0> Epinephrine, also known as adrenalin or adrenaline, is a hormone, neurotransmitter, and medication. <P1-S1>  Epinephrine is normally produced by both the adrenal glands and certain neurons. <P1-S2>  It plays an important role in the fight-or-flight response by increasing blood flow to muscles, output of the heart, pupil dilation, and blood sugar. <P1-S3>  It does this by binding to alpha and beta receptors. <P1-S4>  It is found in many animals and some single cell organisms. <P1-S5>  Napoleon Cybulski first isolated epinephrine in 1895. <SEP> <P2-S0> Small intensely fluorescent cells (SIF cells) are the interneurons of the sympathetic ganglia (postganglionic neurons) of the Sympathetic division of the autonomic nervous system (ANS). <P2-S1>  The neurotransmitter for these cells is dopamine. <P2-S2>  They are a neural crest derivative and share a common sympathoadrenal precursor cell with sympathetic neurons and chromaffin cells (adrenal medulla). <SEP> <P3-S0> Chromaffin cells, also pheochromocytes, are neuroendocrine cells found mostly in the medulla of the adrenal glands in mammals. <P3-S1>  These cells serve a variety of functions such as serving as a response to stress, monitoring carbon dioxide and oxygen concentrations in the body, maintenance of respiration and the regulation of blood pressure. <P3-S2>  They are in close proximity to pre-synaptic sympathetic ganglia of the sympathetic nervous system, with which they communicate, and structurally they are similar to post-synaptic sympathetic neurons. <P3-S3>  In order to activate chromaffin cells, the splanchnic nerve of the sympathetic nervous system releases acetylcholine, which then binds to nicotinic acetylcholine receptors on the adrenal medulla. <P3-S4>  This causes the release of catecholamines. <P3-S5>  The chromaffin cells release catecholamines: ~80% of Adrenaline (Epinephrine) and ~20% of Noradrenaline (Norepinephrine) into systemic circulation for systemic effects on multiple organs (similarly to secretory neurones of the hypothalamus), and can also send paracrine signals. <P3-S6>  Hence they are called neuroendocrine cells.