Which of the following muscle is not involved in damage of craninal part of accessory nerve?
Ans. c. Stylopharyngeus (Ref: Gray's anatomy 40/e p571, 39/e p558; BDC 4/vol-III/223)Stylopharyngeus muscle is innervated by the glossopharyngeal nerve (CN IX), so it's spared after complete transection of cranial part of accessory nerve.Spinal Accessory NerveThe cranial root of accessory nerve (or part) is the smaller of the two portions of the accessory nerve.It is generally considered as a part of the vagus nerve and not part of the accessory nerve proper because the cranial component rapidly joins the vagus nerve and serves the same function as other vagal nerve fibersQ.Fibers of cranial root of accessory (those distributed in pharyngeal branches of vagus) are derived from nucleus ambiguous and probably innervate pharyngeal and palatal muscle except tensor veli palatineQ.Spinal root of accessory provides sole motor supply to sternocleidomastoid and second, third cervical nerves are believed to carry proprioceptive fibers from it.The motor supply to upper and middle portion of trapezius is primarily from spinal accessory nerveQ.Pharyngeal Muscles* Inferior constrictor muscleQ* Middle constrictor muscleQ* Superior constrictor muscleQ* Stylopharyngeus muscleQ* Salpingopharyngeus muscleQ* Palatopharyngeus muscleQPharyngeal muscles are innervated by the pharyngeal branch of the Vagus nerve (CN X) with the exception of the stylopharyngeus muscle, which is innervated by the glossopharyngeal nerve (CN IX)Q.ArchNerve of ArchMuscles of Arch1stTrigeminal (V): mandibularQ and maxillary division* MylohyoidQ* Mastication musclesQ:- TemporalisQ- MasseterQ- Lateral and Medial pterygoidsQ* Anterior belly of digastricQ* Tensor palatine* Tensor tympani2ndFacial nerveQ (VII)* StapediusQ* StylohyloidQ* Posterior belly of digastricQ* Facial expression musclesQ:- Auricularis- BuccinatorQ- FrontalisQ- Platysma- Orbicularis oris and oculiQ3rdGlossopharyngeal NerveQ (IX)* StylopharyngeusQ4thVagus (X): Superior laryngeal NerveQ* Constrictors of pharynxQ* Cricothyroid* Levator palatine6thVagus (X): Recurrent laryngeal Nerve* Intrinsic muscles of Larynx except cricothyroidQ
Cricopharyogeus
Palatopharyngeus
Stylopharyngeus
Salpingopharyngeus
Pharynx