2) Parasympathetic Ganglia : Preganglionic axons of the parasympathetic division synapse with postganglionic neurons in Terminal Ganglia . Most of these ganglia are located close or actually within the wall of the visceral organ. Terminal ganglia in the head have specific names: Ciliary, Pterygopalatine, Submandibular, Otic Ganglions. The terminal ganglia in the sacral region is the pelvic ganglion. Post ganglionic neurons leaving the cranial ganglia innervate eyes, lacrimal & salivary glands. Post ganglionic neurons leaving the pelvic ganglia innervate the pelvic organs.
Structure of the Sympathetic Division
Pathways from the Spinal Cord to the Sympathetic Trunk Ganglia
As mentioned, cell bodies of sympathetic preganglionic neurons are part of the lateral gray horns of all 18 thoracic segments plus the 1 st 2 lumbar segments. Preganglionic axons leave the spinal cord along with the somatic motor neurons at the same segmental level. Myelinated preganglionic sympathetic axons exit through the IVF and pass into the ventral root of a spinal nerve and enter a short pathway called a White Ramus before passing to the nearest sympathetic trunk ganglion on the same side. Collectively, all the white rami are called White Rami Communicantes . Therefore, white rami communicantes contain sympathetic preganglionic axons that connect the ventral ramus of the spinal nerve with the ganglia of the sympathetic trunk.
Pathways from the Sympathetic Trunk Ganglia to the Visceral Effectors
Axons leave the sympathetic trunk in 4 possible ways :
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