True regarding autonomic system is :
Ans. is 'c' is Preganglionic parasympathetic fibres are more lengthy The cell bodies of the post ganglionic parasympathetic neurons are located on or near the body of the viscera and therefore postganglionic neurons are very short.Whereas the cell bodies of the preganglionic parasympathetic neurons are located in the intermediolateral (IML) gray column of the spinal cord or the homologous motor nuclei of the cranial nerves. Therefore the preganglionic neurons have a long course.Ratio of preganglionic and post ganglionic fibres is not 20:1 but is 1:8 or 1:9.Conduction in autonomic fibres and in somatic motor fibres is not the same.Somatic motor fibres are of A. types* (Aa)Autonomic preganglionic axons are of B type*Autonomic postganglionic axons are of C type*Conduction speeds differ in all three A> B> C*Highest centre of integration is not medulla oblongata but hypothalamus.Also knowPreganglionic fibres are myelinated* whereas post ganglionic fibres are unmyelinated*Sympathetic outflow* is through - T1 to L3 & L4Parasympathetic outflow is - Cranio SacralCranial outflow* - III, VI, IX, X C.N.Sacral outflow* - S2 - 4
High center of integration is medulla oblongata.
Conduction autonomic fibers are same as in somatic motor fibers.
Preganglionic parasympathetic fibers are lengthier.
Ratio of pregnanglionic and post ganglionic fibers is 20:1.
Autonomic Nervous System