No. They secrete acetylcholine only.
Sympathetic
No, parasympathetic postganglionic axons secrete the neurotransmitter acetylcholine, not norepinephrine. Norepinephrine is the primary neurotransmitter used by postganglionic neurons of the sympathetic nervous system.
The autonomic nervous system consists of the sympathetic and parasympathetic branches that regulate the heart rate. The sympathetic nerves release neurotransmitters such as norepinephrine to increase heart rate, while the parasympathetic nerves release acetylcholine to decrease heart rate.
The parasympathetic nerves secrete norepinepherine at the AV node (the pacemaker), which slows the heart and reduces stroke volume (the amount of blood the ventricles pump out with each cycle. Sympathetic nerves do the opposite; they secrete epinepherine at the AV node, which stimulates the heart to increase speed and stroke volume, so that more blood is pumped from the heart faster.
Sympathetic nerves increase the heart rate by releasing norepinephrine, while parasympathetic nerves decrease the heart rate by releasing acetylcholine. This affects the pacemaker by altering its firing rate and influencing overall heart rhythm.
Parasympathetic nerves stimulate resting and digesting. Therefore, stomach activity is stimulated by parasympathetic nerves.
The parasympathetic nerves originate in the brainstem and the sacral region of the spinal cord.
Parasympathetic
The heart rate is controlled by the opposing actions of sympathetic and parasympathetic nerves and by the action of epinephrine released from the adrenal gland. Norepinephrine, released by sympathetic nerves in the heart, and epinephrine, released by the adrenal gland, increase the heart rate, while acetylcholine, released from parasympathetic nerves, decreases
adrenel medulla
No
In parasympathetic reflex arc the preganglionic nerve fibre is longer than post ganglionic fibre, that is the synapse occur near the organ or tissue. While in sympathetic reflex arc both the pre and post have moderate sizes. The postganglionic fibre of parasympathetic always secrete acetylcholine as nuerotransmitter while postganglionic fibre of sympatheic reflex arc mostly secrete norepinephrine or epinephrine as nuerotransmitter. Some nerve fibres may secrete acetylcholine. For example postganglionic sympatehtic nerve fibres of sweat glands, pilorectal muscles and few blood vessels