Autonomics DSA Flashcards
What is the path of splanchnic nerves into the adrenal medulla?
Presynaptic sympathetic neurons from T8-L1 pass through the sympathetic trunk without synapsing, enter the the abdomen as splanchnic nerves, and finally enter the adrenal medulla.
Rather than synapsing on postsynaptic neurons, they synapse onto chromatin cells which release nor-epinephrine and epinephrine with sympathetic stimulation.
Where are white rami found?
T1 to L2/L3
Where are gray rami found?
Along the entire sympathetic chain andante all spinal nerves from C1 to Co1
Where are parasympathetic presynaptic neurons found? How do they leave? Where do they synapse?
Within the CMS (brainstem or in the intermediolateral column of the spinal cord levels S2-S4).
They leave via the cranial nerves or pelvic splanchnic nerves to enter the viscera.
Within the target organ, that is why the presynaptic parasympathetic axons are so long
What is cranial outflow?
Parasympathetic innervation from cranial nerves
What is sacral outflow?
Parasympathetic innervation from the pelvic splanchnic nerves.
What does the enteric nervous system consist of?
Neurons distributed in the wall of the GI tract (smooth muscle layer of the stomach, intestines, and submucosa).
What neurotransmitter does the sympathetic nervous system use at presynaptic synapses?
acetylcholine
What neurotransmitter does the sympathetic nervous system use at postsynaptic synapses? What is the exception?
norepinephrine. post-synaptic synapses in sweat glands are cholinergic
What is the pre and post synaptic neurotransmitter of parasympathetic innervation?
Acetylcholine
