Cranial nerves XIXXIXII By Essam Eldin Abdelhady Salama

Cranial nerves XI-X-XI-XII By Essam Eldin Abdelhady Salama

Cranial nerves

The Glossopharyngeal Nerve (IX) • Mixed nerve • Innervates the tongue, (pos. 1/3) pharynx, tonsil. • Test; gag reflex.

Glossopharyngeal nerve • Leave the skull through jugular foramen • Passes forwards between internal jugular vein and external carotid artery. • Deep to styloid process. • Between external and internal carotid arteries at posterior border of stylopharyngeus then lateral to it. • Reaches the pharynx by passing between middle and inferior constrictor, deep to hyoglossus, where it breaks into terminal branches.

Glossopharyngeal nerve • Ganglia • Superior ganglion small, with no branches. • Inferior ganglion, large carries general sensations from pharynx, soft palate and fauces.

Branches. • Of communications: • Inferior ganglion and • superior cervical sympathetic ganglion. • Superior ganglion and auricular branch of vagus. • Its trunk and facial nerve at stylomastoid foramen

Branches. • • • Of distribution: Tympanic. Stylopharyngeus. Pharyngeal. Tonsillar. Lingual.

Gloosopharyngeal nerve • • • • jf--jugular foramen sg--superior ganglion ig--inferior ganglion tp--tympanic plexus lpn--lesser petrosal nerve fo--foramen ovale og--otic ganglion pg--parotid gland sp--nerve to stylopharyngeus muscle pb--pharyngeal branch ncbcs--nerve to carotid body carotid sinus Red solid -- motor Red dotted -parasympathetic Yellow -- sensory (afferent)

Gloosopharyngeal nerve

The Vagus Nerve (X) • Mixed nerve • Vital to autonomic control of visceral function. • Test; check for hoarseness, open wide and say "AH"

Vagus nerve • Leaves the skull through jugular foramen • Descends within carotid sheath • Enters thorax through its inlet • Descends through superior mediastinum. • It has two ganglia • Superior ganglion in the jugular foramen • Inferior ganglion, just below the jugular foramen

Branches • Of communication • Superior ganglion and • inferior ganglion of glossopharyngeal nerve, • superior cervical sympathetic ganglion. • facial nerve. • Inferior ganglion and • cranial part of accessory nerve, • hypoglossal nerve, • superior cervical sympathetic ganglion. • 1 st cervical nerve.

Branches • • Of distribution: Meningeal Auricular Pharyngeal To carotid body Superior laryngeal Right recurrent laryngeal Cardiac.

Vagus nerve • • • • jf--jugular foramen sg--superior ganglion ig--inferior ganglion pb--pharyngeal branch spc--superior pharyngeal constrictor sl--superior laryngeal nerve il--internal laryngeal el--external laryngeal ct--cricothyroid muscle mpc--middle pharyngeal constrictor rl--recurrent laryngeal nerve pc--pharyngeal constrictors csn--carotid sinus nerve Red solid -- motor Red dotted -parasympathetic Yellow -- sensory (afferent)

Vagus nerve

The accessory nerve (XI) • Internal branch Innervates swallowing muscles • External branch Controls muscles associated with pectoral girdle. • Test; shoulder raise or turning the head

Accessory nerve • Cranial root from medulla oblongata • spinal root upper 5 -6 segments of spinal nerves. • They join inside the jugular foramen, just outside it they separate.

Accessory nerve • The cranial part • Joins vagus, distributed along pharyngeal and recurrent laryngeal. • The spinal part • Runs backwards and laterally to sternomastoid and trapezius.

Spinal accessory • Fm; foramen magnum • Jf; jugular foramen

Accessory nerve

The hypoglossal nerve (XII) Voluntary motor control for tongue movements. Test, stick out the tongue.

Hypoglossal nerve • Leave the skull through hypoglossal canal. • Passes lateral and downwards then • Descends vertically between the internal carotid artery and internal jugular vein. • Turns forwards crossing internal and external carotid arteries and 1 st part of lingual artery.

Hypoglossal nerve • Runs on the lateral surface of hyoglossus, related to lingual nerve, deep part of submandibular gland submandibular duct. • Runs lateral to genioglossus, where it breaks to supply the tongue.

Branches • • • Of communications Vagus; Inferior ganglion. Auricular branch of vagus. Cervical nerves; 1 st and 2 nd Sympathetic plexus; Superior cervical sympathetic ganglion Lingual nerve.

Branches • • • Of distribution: Meningeal. Thyrohyoid. Descending. Muscular.

Hypoglossal nerve • C 1 --first cervical nerve • hf-hypoglossal canal

Hypoglossal nerve