<p>Lecture: 12 Head and neck Dr. Omar Riadh </p><p>15-11-2017 Maxillary nerve:-</p><p>Is the second of three division of trigeminal nerve, arises from the trigeminal ganglia and passes through foramen rotundum, then emerges from the foramen into the pterygopalatine fossa. Then the nerve curves laterally through pterygomaxillary fissure to the infratemporal fossa, here it turns sharply forward into infra-orbital groove as infraorbital nerve.</p><p>Branches:-</p><p>1- Meningeal branch:- arises near the origin of the nerve.</p><p>2- Two ganglionic branches connected to pterygopalatine ganglia.</p><p>3- Posterior superior alveolar nerve.</p><p>4- Middle superior alveolar nerve.</p><p>5- Anterior superior alveolar nerve.</p><p>6- Zygomatic nerve:- pass through inferior orbital fissure and divided into zygomaticotemporal and zygomaticofacial nerves.</p><p>7- Infraorbital nerve. Pterygopalatine ganglia:-</p><p>Is a small triangular ganglia lies in the superior part of pterygopalatine fossa. It have the following roots:-</p><p>1- Sensory:- the ganglia is suspended from the inferior aspect of the maxillary nerve by two ganglionic branches, the sensory fibers in these branches pass directly through the ganglia into its branches.</p><p>2- Sympathetic:- through the deep petrosal nerve which carries postganglionic sympathetic fibers from internal carotid plexus.</p><p>3- Parasympathetic:- through greater petrosal nerve which is branch of facial nerve arises near the geniculate ganglia, it passes through the petrous temporal bone and appears in the middle cranial fossa</p><p>1 through the hiatus of greater petrosal nerve, then it passes forward and unites with deep petrosal nerve forming nerve of pterygoid canal which passes forward in the pterygoid canal in the sphenoid bone to reaches the pterygopalatine ganglia. Only the preganglionic parasympathetic fibers of greater petrosal nerve synapse in the ganglia and postganglionic parasympathetic fibers supply the lacrimal gland (through the zygomaticotemporal nerve) and the glands of the nose, palate and pharynx through the branches of the ganglia which also transmit sensory (maxillary nerve) and sympathetic fibers.</p><p>Branches of the pterygopalatine ganglia:-</p><p>1- Greater palatine nerve:- descends through the greater palatine canal with the descending palatine artery , pass through greater palatine foramen. In the incisive foramen it communicates with the nasopalatine nerve. It gives posterior nasal branch to the mucous membrane of the nose.</p><p>2- Lesser palatine nerve:- to the palatine tonsil and soft palate.</p><p>3- Orbital branches:- pass through inferior orbital fissure to supply the orbital periosteum.</p><p>4- Nasopalatine and posterior nasal nerve:- pass through sphenopalatine foramen to the mucous membrane of the nose.</p><p>5- Pharyngeal nerve in the pharyngeal canal. The mouth:-</p><p>Extends from the lips anteriorly to the oropharyngeal isthmus posteriorly, it is divided into:-</p><p>1- The vestibule:- which lies between the lips and cheek externally and the gum and teeth internally.</p><p>2- Mouth proper:- which lies within the alveolar arches, gum and the teeth, the roof is formed by the hard palate and soft palate while the floor is formed by the tongue. The tongue:-</p><p>2 Muscular organ in the floor of mouth. It have intrinsic muscles and extrinsic muscles. It connected to three bones which are mandible, hyoid and styloid process through the extrinsic muscles ( genioglossus, hyoglossus and styloglossus).</p><p>The dorsum of the tongue divided by a V-shaped sulcus terminalis into anterior 2/3 and posterior 1/3 which have different nerve supply. The apex of the V is directed posteriorly and marked by a small pit the foramen cecum. </p><p>Muscles of the tongue:-</p><p> a- Extrinsic muscles:-</p><p>1- Hyoglossus.</p><p>2- Genioglossus.</p><p>3- Styloglossus.</p><p>4- Palatoglossus.</p><p> b- Intrinsic muscles:-</p><p>1- Superior longitudinal.</p><p>2- Inferior longitudinal.</p><p>3- Vertical.</p><p>4- Transverse.</p><p>Nerve supply of the tongue:-</p><p>1- General sensation of anterior 2/3 of the tongue by lingual nerve.</p><p>2- Special sensation of anterior 2/3 of the tongue by chorda tympani.</p><p>3- General and special sensation of posterior 1/3 of the tongue by glossopharyngeal nerve.</p><p>4- Small area adjacent to epiglottis supplied by internal branch of superior laryngeal nerve.</p><p>5- Motor supply of the tongue by hypoglossal nerve.</p><p>3 Arterial supply of the mouth:-</p><p>By lingual artery and also the palate is supplied by numbers of branches from facial, ascending pharyngeal artery, descending palatine artery. the tonsil supplied by facial artery. The pharynx:-</p><p>Muscular tube about 12 cm in length start from the base of skull to the level of cricoid cartilage which is opposite to the 6th cervical vertebrae, where it becomes continuous with the esophagus. It is situated behind the nose, mouth and larynx. The wall of the pharynx consist of:-</p><p>1- Mucous membrane which is continuous with that of nasal cavity, mouth and larynx.</p><p>2- Fibrous membrane which lies between the mucous membrane and the muscular layer.</p><p>3- Muscular layer consist of superior, middle and inferior constrictor, stylopharyngeus, salpingopharyngeus and palatopharyngeus muscles.</p><p>Nerve supply of the pharynx:- is by pharyngeal plexus which is formed by branch of vagus, glossopharyngeal and branch from superior cervical sympathetic ganglia. The motor supply is by cranial part of accessory nerve through the vagus nerve which supplies all the muscles of pharynx except stylopharyngeus which is supplied by glossopharyngeal nerve. The sensory supply of the pharynx is mostly through glossopharyngeal nerve via the pharyngeal plexus and also by superior laryngeal nerve via internal laryngeal nerve and maxillary nerve.</p><p>Blood supply of the pharynx:- by ascending pharyngeal artery, ascending palatine, superior thyroid, facial, lingual and maxillary arteries.</p><p>Venous drainage of the pharynx by pharyngeal venous plexus which drain into internal jugular vein.</p><p>The pharynx is divided into three part:- nasal, oral and laryngeal part. 1- Nasopharynx:-</p><p>4 It lies behind the nasal cavity and above the soft palate, it has roof, floor, anterior wall, posterior wall and lateral wall.</p><p>The roof and posterior wall:- form a continuous curved surface of mucous membrane, this covers the inferior surface of sphenoid, basilar part of occipital bone and the superior part of longus capitis muscle. A collection of lymphoid tissue called the pharyngeal tonsil is presents in the submucosa of the pharynx when enlarged in children called the adenoids and may be of sufficient size to block the nasal part of pharynx gives a nasal quality to the voice.</p><p>The floor:- is formed by sloping upper surface of soft palate, the pharyngeal isthmus is the opening in the floor between the free edge of soft palate and the posterior pharyngeal wall.</p><p>The anterior wall:- is formed by the posterior nasal aperture separated by the posterior edge of nasal septum.</p><p>The lateral wall:- there is the orifices of auditory tube which surrounded superiorly and posteriorly by elevation called tubal ridge which contains lymphoid tissue so sometimes called tubal tonsil and this orifice connects the pharynx to the middle ear cavity and it is important for equilibrium of pressure at the two side of tympanic membrane. From the tubal ridge the salpingopharyngeus muscle descends into the lateral wall of pharynx produces vertical fold of mucous membrane called the salpingopharyngeal fold.</p><p>Posterior to the salpingopharyngeal fold there is a deep recess called the pharyngeal recess. </p><p>5</p>