epinephrine is also known as adrenaline and stimulates the sympathetic nervous system.
epinephrine is also known as adrenaline and stimulates the sympathetic nervous system.
also known as adrenaline stimulates the sympathetic nervous system?
epinephrine
the autonomic nervous system controls all automatic functions in the body and contains two subsections within it that aids in response to an acute stress reaction. these two subunits are the sympathetic nervous system and the parasympathetic nervous system. the sympathetic response is colloquially known as the "fight or flight" response, indicated by accelerated pulse and respiration rates, pupil dilation, and a general feeling of anxiety and hyper-awareness. this is caused by the release of epinephrine and norepinephrine from the adrenal glands. the epinephrine and norepinephrine strike the beta receptors of the heart, which feeds the heart sympathetic nerve fibers in order to increase the strength of heart muscle contraction; as a result more blood gets circulated, increasing the heart rate and respiratory rate. the sympathetic nervous system also stimulates the skeletal system and muscular system in an effort to pump more blood to those areas to handle the acute stress. simultaneously the sympathetic nervous system inhibits the digestive system and the urinary system in order to optimize blood flow to the heart, lungs, and skeletal muscles. this plays a role in the alarm reaction stage. the para-sympathetic response is colloquially known as the "rest and digest" response, indicated by reduced heart and respiration rates, and more obviously by a temporary loss of consciousness if the system is fired at a rapid rate. the parasympathetic nervous system stimulates the digestive system and urinary system in order to send more blood to those systems to increase the process of digestion. in order to do this, it must inhibit the cardiovascular system and respiratory system in an effort to optimize blood flow to the digestive tract causing low heart and respiratory rates. parasympathetic plays no role in acute stress response (vanputte regan russo 2014).
acute stress reaction
adrenocorticotropic hormone (acth) and the sympathetic nervous system stimulate the synthesis of adrenaline precursors by enhancing the activity of tyrosine hydroxylase and dopamine β-hydroxylase, two key enzymes involved in catecholamine synthesis. acth also stimulates the adrenal cortex to release cortisol, which increases the expression of pnmt in chromaffin cells, enhancing adrenaline synthesis. this is most often done in response to stress. the sympathetic nervous system, acting via splanchnic nerves to the adrenal medulla, stimulates the release of adrenaline. acetylcholine released by preganglionic sympathetic fibers of these nerves acts on nicotinic acetylcholine receptors, causing cell depolarization and an influx of calcium through voltage-gated calcium channels. calcium triggers the exocytosis of chromaffin granules and, thus, the release of adrenaline (and noradrenaline) into the bloodstream.
adrenaline