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Where are parasympathetic ganglia located in relation to their target organs?

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Diagram comparing action potential conduction in myelinated and unmyelinated axons, showing a neuron with labeled cell body, myelin sheath, nodes of Ranvier, and the flow of electrical signals along each type of axon. — nervous system In a myelinated axon, the myelin sheath prevents the local current (small black arrows) from flowing across the membrane. This forces the current to travel down the nerve fibre to the unmyelinated nodes of Ranvier, which have a high concentration of ion channels. Upon stimulation, these ion channels propagate the action potential (large green arrows) to the next node. Thus, the action potential jumps along the fibre as it is regenerated at each node, a process called saltatory conduction. In an unmyelinated axon, the action potential is propagated along the entire membrane, fading as it diffuses back through the membrane to the original depolarized region.

Parasympathetic ganglia are typically located in close proximity to, or directly within, the target organs or tissues they innervate.12

This anatomical arrangement contrasts with the sympathetic nervous system, where ganglia are generally situated at more distant sites from their target organs. Specifically, parasympathetic ganglia may be found in the following locations:2

In the head: Examples include the ciliary, pterygopalatine, and otic ganglia.1
Near or within organs: Many ganglia are located near organs, such as the cardiac ganglia near the heart or the pelvic ganglion situated a short distance from the urinary bladder.1
Embedded in the organ: In many cases, such as within the trachea, bronchi, and the gastrointestinal tract, the ganglia are embedded directly in the end organ itself.1