The sympathetic nervous system is involved in the stimulation of activities that prepare the body for actions called fight-or-flight responses (responses that serve to fight off or retreat from danger). The parasympathetic nervous system activates tranquil functions as in eating and digesting. It is sometimes called the rest-and-repose response. Generally, both sympathetic and parasympathetic systems target the same organs, but often have opposite reactions.
Both your sympathetic and parasympathetic neurons have a constant rate of firing under normal conditions. This is called their "tone", and it maintains the normal rate of your heartbeat, keeps your blood pressure within a normal range and such to maintain homeostasis. Of course, the sympathetic and parasympathetic firing rate changes greatly during fight-or-flight responses and such.
They are sympathetic but an exception - ACh is released as a post-synaptic neurotransmitter rather than Adrenaline/Noradrenaline.Illicitinga parasympathetic response will not stimulate these neurons and therefore sweating is not a parasympathetic side effect.However, as post-synaptic sweat glands contain Muscarinic receptors and not adrenoceptors the administration of a non-selective Muscarinic agonist would result in both a parasympathetic response such as constriction of the pupil or decreased heart rate as well as sweating due to the activation of these sympathetic post-synaptic MAChR in the sweat glands.Atropine would reduce all parasympathetic responses and stop sweating.
Sympathetic nerves and parasympathetic nerves are part of the Autonomic Nervous system. They control body functions that are involuntary and are responsible for many responses that range from 'flight-or-flight' as part of the stress response, to digestion, and even sexual arousal. The Sympathetic branch of the Autonomic Nervous system is sometimes called 'thoracolumbar outflow' and the parasympathetic branch is called the 'craniosacral outflow.'This refers to the regionds where the nerve roots are located along the verebral columb.
The autonomic system controls responses that are involuntary, such as maintaining breathing or keeping your heart at a steady rate. It consists of parasympathetic and sympathetic divisions. Parasympathetic is for 'rest and digestion' and symapthetic is for 'fight or flight' In short sympathetic speeds up body reactions but slows digestion and parasympathetic slows body reactions and assists and controls digestion. In reality both systems will function in conjunction with each other to bring about normal body states.
Because NE and Epinephrine are secreted into the blood as part of the sympathetic response
The Parasympathetic Division is in charge of "rest and digest" and has a calming effect on many body functions. The sympathetic division is in charge of the "fight or flight" increasing breathing rate allowing more oxygen intake, and increase of heart rate allowing more blood to flow throughout body.
All the unvoluntary things.... You have the parasympathetic nervous and the sympathetic nervous system. Parasympathetic nervous system: Long pre-g, short post-g aka the craniosacral nervous system - The slow responses.... like slow heart rate by vagus nerve Sympathetic nervous system: Short preg-, long post-g aka the thoracolumbar nervous system - Fight or flight responses like increase heart rate . Pre-g nicotinic stimulation to adrenal medulla which releases adrenaline (epinephrine)
Because crying is an emotional response that is related to the parasympathetic nervous system. When it gets activated, most all of the parasympathetic responses are elicited, and one of them is to increase the secretion of mucous throughout the body along with the tears. So that is why your nose runs too.