Cranial Nerves IX and X PDF

Glossopharyngeal Nerve • Sensory components – Taste from posterior 1/3 tongue SVA Carotid sinus and body input (baroreceptors and chemoreceptors) GVA General sensory from posterior 1/3 tongue and posterior wall of upper pharynx General sensory from around ear GSA • Motor components – GVE, ANS inne...

Glossopharyngeal Nerve • Sensory components – Taste from posterior 1/3 tongue SVA Carotid sinus and body input (baroreceptors and chemoreceptors) GVA General sensory from posterior 1/3 tongue and posterior wall of upper pharynx General sensory from around ear GSA • Motor components – GVE, ANS innervation of the parotid gland – SVE innervation of the stylopharyngeus muscle Glossopharyngeal nuclei SVA GVA caudal GVE GSA SVE • Fiber types – SVA (nucleus solitarius) – GVA (nucleus solitarius) – GSA (trigeminal spinal or chief) – SVE (nucleus ambiguus) – GVE (inferior salivatory) • Ganglia of glossopharyngeal n. – Superior (very small) – Inferior Glossopharyngeal nerve (CNIX) • special visceral afferent (SVA) – taste from posterior third of tongue – inferior ganglionnucleus solitariusthalamusprimary sensory cortex (nucleus in medulla) Glossopharyngeal nerve (CNIX) • general visceral afferent (GVA) • Sensation from carotid body and sinus • project to nucleus solitarius in medulla Glossopharyngeal nerve (CNIX) • general somatic afferent (GSA) • Touch, pain and temperature from posterior 1/3 tongue, uvula, mid pharynx • cell bodies in superior ganglion • project to trigeminal nucleus then sensory cortex (via thalamus) Glossopharyngeal nerve (CNIX) • special visceral efferent (SVE) – stylopharyngeus muscle (muscle of the pharynx) – nucleus ambiguus in medulla Glossopharyngeal nerve (CNIX) • general visceral efferent (GVE) • Dark blue fibers in picture – parasympathetic control of parotid gland – inferior salivary nucleus in medulla – otic ganglion – Also have GVE to carotid body and sinus (ambiguous) Vagus Nerve • Sensory: – Taste from the epiglottis – Sensory from thoracic and abdominal structures – General sensory from around the ear • Motor: – Smooth and cardiac muscle and glands of the thoracic and abdominal viscera – Skeletal muscles of the soft palate, pharynx, larynx, and upper esophagus Vagus nuclei SVA GVA caudal GVE GSA SVE • Fiber types – SVA (nucleus solitarius) – GVA (nucleus solitarius) – GSA (trigeminal chief or spinal) – SVE (nucleus ambiguus) – GVE (dorsal motor of X) • Ganglia of vagus n. – Superior (jugular) – Inferior (nodose) Vagus –GSA from lower pharynx, larynx, portion external ear, tympanic membrane SVA – taste from vallecula and epiglottis area (not shown) Vagus nerve (CN X) • general visceral afferent (GVA) • pain and temperature, distension from visceral structures (thoracic and abdomen, aortic body and sinus) • Vagus has more afferent fibers that efferent!! Vagus – visceromotor, GVE Vagus – branchiomotor, SVE Most of the muscles of the palate and pharynx ALL of the muscles of the larynx Gag Reflex Sensory arc- Glossopharyngeal IX Motor arc- Vagus X Muscles of the soft palate are ‘pullers’ Innervated by Vagus N. Deviate AWAY from side of lesion FYI • • • • • • V = CN V X = CN X Greater auricular n. Lesser occipital n. Facial n. = * External auditory meatus – CN V = anterior and superior walls – CN X = posterior and inferior walls • Tympanic membrane – Outer surface = mostly by CNV; some by CN X – Interior CN VII – Inner surface = CN IX V LesserOcc V V V V V GrAur * * * X V GrAur * X * X GrAur * X GrAur