All of the following statements about the vagus nerve are true except that it -
Ans. is 'b' i.e., Carries postganglionic parasympathic fibres Vagus nerve carries the parasympathetic fibres along with them.These fibres are preganglionic parasympathetic fibres (not postganglionic).These preganglionic parasympathetic fibres then synapse at the ganglia which are located close to the organs they innervate.From this ganglia post ganglionic parasympathetic fibres originate and supply the respective organs.Remember that this is a common feature of all the cranial nerves which carry parasympathetic fibres i.e., Cranial N - III, VII, IX, XThe route of parasympathetic fibres carried by these nerves is :Preganglionic parasympathetic fibres are carried along with the cranial nerve fibres.They synapse in a motor ganglia located very close to or with in the end organ system.From the ganglia, the postganglionic parasympathetic fibres arise.Branches of the vagus nerve (CN X)Auricular bunches - Cutaneous to the external ear.Pharyngeal branch - To pharyngeal plexus, which supplies all muscles of the pharynx and soft palate except stylopharyngeus (CN IX) and tensor palati (mandibular nerve)Superior laryngeal N - Divides into internal and external branchesC1- internal branch of superior laryngeal n; sensory to mucosa above vocal cords.C2- External branch of superior laryngeal n; motor to inferior constrictor muscle and cricothyroid muscle.Recurrent laryngeal nerveCardiac branches - supplies the heartEsophageal plexusAnterior vagal trunk to anterior stomach and liverPosterior vagal trunk to posterior stomach and then (via celiac plexus) to liver, kidney, small intestine and large intestine upto the splenic flexure.
Supplies heart & lung
Carries postganglionic parasympathetic fibers.
Innervates right two third of transverse colon
Stimulates peristalsis & relaxes sphincters
Nerves of Abdomen