Neuro-Anatomy Of Upper Airway BY AHMAD YOUNES PROFESSOR OF THORACIC MEDICINE

1. Neuro-Anatomy Of Upper Airway BYAHMAD YOUNESPROFESSOR OF THORACIC MEDICINE Mansoura Faculty of Medicine

2. Upper Airway Anatomy & Physiology Anatomy 1-Nose 2-Oral Cavity 3-Pharynx

3. Function of the Upper Airway 1-Conduct Air 2-To prevent foreign materials from entering the lower airway 3-Smell / Speech

4. Epithelial Cell Type • Squamous Cells • Cuboidal Cells • Columnar Cells Classification of Epithelium by Layers 1- Simple Epithelium – Single Layer Simple squamous Simple cuboidal Simple columnar 2-Stratified Epithelium – Multiple Layers 3-Pseudostratified – Single Layer but appears stratified . Pseudo means “false”

6. Nose Anatomy of the Nose 1-Bone and Cartilage 2-Partition in the nose is called the nasal septum 3-Air enters through the nostrils or nares 4-Two nasal passages are called choanae 5-Vibrissae filter the incoming gas

7. Anatomy of the Nose 6-First 1/3 is covered by stratified squamous epithelium (PROTECTION) • Posterior 2/3 is pseudostratified ciliated columnar epithelium (MUCUS SECRETION) • Mucous secreting glands are found in the posterior 2/3 of nose • Bony Protrusions on the lateral wall are called nasal turbinates or conchae • Extensive capillary network • Constrict or dilate to change blood flow

8. Physiology of the Nose • Nose can filter particles down to 5 m (microns) in diameter • Two factors which decrease the humidification and filtering ability of the nose is: Mouth Breathing and Placement of an ET (endotracheal) tube. Function of the Nose 1-Heat, Humidify and Filter the incoming gas 2-Smell 3-Speech

9. Bony skeleton of the nose I. Roof, formed by: - Anterior part------ Nasal part of the frontal bone + Nasal bone. - Middle part ------ Cribriform plate of the ethmoid bone. - Posterior part------Body of the sphenoid bone. I. Floor, formed by: - Anteriorly: Palatine process of the maxilla. - Posteriorly : Horizontal plates of the palatine bone. III. Medial wall (nasal septum), formed by: - Postero-inferior-------Vomer. - Superiorly ----- Perpendicular plate of the ethmoid bone. - Antero-inferior -----Septal cartilage.

11. Lateral wall of the nose • Conchae • They are bony plates covered with mucous membrane. • They are three (superior, middle, and inferior nasal conchae). 2. Meatuses :They are depressions below and lateral to each concha (superior, middle, and inferior meatuses). a-Superior meatus: It receives the opening of posterior ethmoidal air sinus. b. Middle meatus:- It receives the following openings: i. Anterior ethmoial air sinus. ii. Frontal air sinus. iii. Maxillary air sinus. c. Inferior meatusIt receives the nasolacrimal duct.

13. Arterial supply of the nose 1. Sphenopalatine artery . It is a branch from the maxillary artery (main arterial supply). 2. Septal branch of the superior labial artery from facial artery. 3. Ascending branch of the greater palatine artery from the maxillary artery . • There is anastomoses between the above three arteries to form “Kieselbach's plexus” on the antero-inferior part of the nasal septum (Little’s area). This area is a common site for epistaxis . 4. Anterior and posterior ethmoidal branches of the ophthalmic artery. supply the roof and upper parts of the lateral wall and septum.

15. Deviated Septum • The nasal septum can be deviated to the right or left , • More often to the left

16. Paranasal Sinuses • Definition: They are air-filled spaces in certain bones which form the boundary of the nasal cavity. • They open into the lateral wall of the nose. Types: 1. Maxillary sinus -------- Inside the body of the maxilla. 2. Frontal sinus ----------- Between the two plates of the frontal bone. 3. Sphenoid ---------------- Inside the body of the sphenoid bone. 4. Ethmoid ----------------- Inside the lateral part of the ethmoid bone • - All the sinuses are present at birth except the frontal sinus which appears during the second year.

18. Functions 1. Warming and humidifying the inspired air. 2. Diminishing the weight of the skull. 3. They add resonance to the voice.

19. Nerve supply of the nose • Lateral wall • Olfactory area (1 cm)  Olfactory nerves.(this area includes the roof and upper parts of the septum and lateral nasal walls) • Vestibular area Infraorbital nerve. • Respiratory area of the lateral wall: • Antero-superior  anterior ethmoidal N. • Antero-inferior (inf. concha)  Internal nasal nerve(from anterior ethmoidal N) c. Postero-superior Lateral posterior superior nasal branches. d.Postero-inferior Lateral posterior inferior nasal branches. (from greater palatine N).

20. Nasal septum • Olfactory area Olfactory N. • Anterior part  Internal nasal N. (from the anterior ethmoidal nerve). • Postero-superior part  Medial posterior superior nasal branches. (from sphenopalatine ganglion). • Postero-inferior part  Nasopalatine nerve. ( long sphenopalatine nerve). • N.B: The nasopalatine nerve, greater and lesser palatine nerves, medial and lateral posterior superior nasal nerves, and the posterior inferior nasal nerve are branches from the sphenopalatine ganglion.

22. Anatomy of the Oral Cavity • Roof of the mouth is formed by the hard and soft palate • Hard – Bony portion • Soft – Fleshy portion • Uvula is the soft fleshy structure • Epithelium is stratified squamous epithelium which is non-ciliated. • Palatine (faucial) tonsils are located on each side of the oral cavity.

23. MUSCLES OF SOFT PALATE • The muscles of the palate are levator veli palatini, tensor veli palatini, palatoglossus, palatopharyngeus, musculus uvulae . • With the exception of tensor veli palatini, which is supplied by the motor branch of the mandibular division of the trigeminal through the nerve to medial pterygoid, and stylopharyngeus, which is supplied by the glossopharyngeal nerve, the muscles are supplied by the cranial part of the accessory nerve via the pharyngeal plexus.

26. LEVATOR VELI PALATINI • Levator veli palatini arises by a small tendon from a rough area on the inferior surface of the petrous part of the temporal bone, in front of the lower opening of the carotid canal. Its fibres spread in the medial third of the soft palate between the two strands of palatopharyngeus to attach to the upper surface of the palatine aponeurosis as far as the midline, where they interlace with those of the contralateral muscle. Thus the two levator muscles form a sling above and just behind the palatine aponeurosis. • The primary role of the levator veli palatini muscles is to elevate the almost vertical posterior part of the soft palate and pull it slightly backwards.

27. TENSOR VELI PALATINI • Tensor veli palatini arises from the scaphoid fossa of the pterygoid process and posteriorly from the medial aspect of the spine of the sphenoid bone. Some fibres may be continuous with those of tensor tympani. Inferiorly, the fibres converge on a delicate tendon that turns medially around the pterygoid hamulus to pass through the attachment of buccinator to the palatine aponeurosis and the osseous surface behind the palatine crest on the horizontal plate of the palatine bone. • Acting together the tensor veli palatini muscles tauten the soft palate, principally its anterior part, and depress it by flattening its arch. Acting unilaterally, the muscle pulls the soft palate to one side.

28. MUSCULUS UVULAE • Musculus uvulae arises from the posterior nasal spine of the palatine bone and the superior surface of the palatine aponeurosis, and lies between the two laminae of the aponeurosis. It runs posteriorly above the sling formed by levator veli palatini and inserts beneath the mucosa of the uvula. The two sides of the muscle are united along most of its length. • By retracting the uvular mass and thickening the middle third of the soft palate, musculus uvulae aids levator veli palatini in palatopharyngeal closure. The two muscles run at right angles to each other and their contraction raises a 'levator eminence' which helps seals off the nasopharynx.

29. The palatopharyngeus muscle • The palatopharyngeus muscle, which forms the posterior faucal pillars. It does not affect the position of the tongue. • Passavant's muscle (palatopharyngeal :It has been described as a part of the superior constrictor and palatopharyngeus muscles, when it contracts, it forms a ridge (Passavant's ridge) when the soft palate is elevated. The change from columnar, ciliated, 'respiratory' epithelium to stratified, squamous epithelium that takes place on the superior aspect of the soft palate occurs along the line of attachment of the palatopharyngeal sphincter to the palate.

30. PALATOGLOSSUS • Palatoglossus is narrower at its middle than at its ends. Together with its overlying mucosa it forms the palatoglossal arch or fold. • It arises from the oral surface of the palatine aponeurosis where it is continuous with its fellow. It extends forwards, downwards and laterally in front of the palatine tonsil to the side of the tongue. Some of its fibres spread over the dorsum of the tongue, others pass deeply into its substance to intermingle with fibres of the intrinsic transverse muscle. • Palatoglossus elevates the root of the tongue and approximates the palatoglossal arch to its contralateral fellow, thus shutting off the oral cavity from the oropharynx.

31. The Tongue • You should identify structures on the tongue sufacee papillae (bumps on the tongue) foramen caecum (the little pouch on the root of the tongue) frenulum (the connective tissue between the underside of the body of the tongue and the mylohyoid muscle) valleculae (two shallow oval pits formed by the membrane between the tongue and the epiglottis; food passes through them) .

32. The muscles of the tongue • The muscles of the tongue are divided into extrinsic (originating outside the tongue) and intrinsic (situated within the tongue) muscles. • The four major extrinsic muscles of the tongue The mylohyoid muscle, originates from the myloid (interior) ridge of the mandible on each side and meets at its midline raphe. The mylohyoid muscle then inserts at the anterior part of the hyoid bone. which is responsible for raising the body of the tongue in high vowels and velar consonants . The hyoglossus, which pulls it downwards (and slightly backwards).The styloglossus, which pulls the tongue upwards and backwards . The genioglossus, which forms the bulk of the inferior part of the tongue and pulls the body of the tongue

35. The muscles of the tongue • Mylohyoid muscle forms the floor of the mouth and controls the raising of the tongue. It is also an elevator of the hyoid bone, and hence elevates the larynx. • The hyoglossus is a broad, flat muscle running from the greater horn of the hyoid to the posteroinferior lateral aspects of the tongue (on the sides of the lower back of the tongue). It is a depressor (lowerer) of the tongue. • The styloglossus extends from the styloid process, a projection of the skull at about the level of the ear down into the lateral aspect of the tongue, passes between the medial and superior pharyngeal constrictors and separate it from the surrounding tissue , then interdigitating with the inserting fibers of the hyoglossus.

37. The muscles of the tongue • The genioglossus is attached to a point on the mandible about halfway between the chin and the lower incisors (front teeth). From this point, the muscle fibers fan out posteriorly and superiorly(backwards and upwards) to form the inferior portion of the tongue. • A small group of inferior and lateral fibers of this muscle attach to the hyoid bone. Follow the fibers of the inferior surface of the genioglossus muscle down medially, deep to the hyoid bone, and observe how they insert into the root of the epiglottis.

38. The muscles of the tongue • The palate-glossus muscle, a small muscle that can assist the action of the styloglossus. The Palate-glossus muscle can be found on the postero-lateral (back, side) aspect of the tongue below the mucous membrane of the anterior faucal pillar (located on the walls of the mouth on either side of the uvula). From the undersurface of the soft palate, this muscle curves inferiorly (downwards) to insert into the side of the tongue. • The Palate-glossus is innervated by the vagus nerve (the Xth), whereas all the other tongue muscles are innervated by the hypoglossal nerve (the X1th).

39. The muscles of the tongue • The intrinsic muscles of the tongue include: the superior longitudinal muscle, with fibers that run antero-posteriorly (from the front to the back) along the superior surface of the tongue, just below the mucous membrane, the inferior longitudinal muscle, with fibers that run along the sides of the tongue, from the root to the tip of the tongue. Anteriorly (to the front) these fibers join those of the styloglossus muscle, the verticalis muscle, with fibers that arise near the midline of the superior surface of the tongue and course inferolaterally (down and to the sides) to insert into the sides of the tongue, the transversalis muscle, with fibers that extend from the mucous membrane on the sides of the tongue to the median septum, which divides the tongue in half saggitally (down the midline).

42. The Pharynx • The pharynx is situated behind the nasal cavities, the mouth, and the larynx and may be divided into nasal, oral, and laryngeal parts. • The pharynx is funnel shaped, its upper, wider end lying under the skull and its lower, narrow end becoming continuous with the esophagus opposite the sixth cervical vertebra. • The pharynx has a musculomembranous wall, which is deficient anteriorly. Here, it is replaced by the posterior openings into the nose (choanae), the opening into the mouth, and the inlet of the larynx. • By means of the auditory tube, the mucous membrane is also continuous with that of the tympanic cavity.

43. Muscles of the Pharynx • The muscles in the wall of the pharynx consist of the superior, middle, and inferior constrictor muscles , whose fibers run in a somewhat circular direction, and the stylopharyngeus and salpingopharyngeus muscles, whose fibers run in a somewhat longitudinal direction. SUPERIOR CONSTRICTOR • The superior constrictor is a quadrilateral sheet of muscle and is thinner than the other two constrictors. • It is attached anteriorly to the pterygoid hamulus, the posterior border of the pterygomandibular raphe, the posterior end of the mylohyoid line of the mandible, and, by a few fibres, to the side of the tongue. The fibres curve back into a median pharyngeal raphe which is attached superiorly to the pharyngeal tubercle on the basilar part of the occipital bone.

45. MIDDLE CONSTRICTOR • The middle constrictor is a fan-shaped sheet attached anteriorly to the lesser cornu of the hyoid and the lower part of the stylohyoid ligament and to the whole of the upper border of the greater cornu of the hyoid. • The lower fibres descend deep to the inferior constrictor to reach the lower end of the pharynx, the middle fibres pass transversely and the superior fibres ascend and overlap the superior constrictor. • All fibres insert posteriorly into the median pharyngeal raphe.

46. INFERIOR CONSTRICTOR • The inferior constrictor is the thickest of the three constrictor muscles, and is usually described in two parts, cricopharyngeus and thyropharyngeus. • Cricopharyngeus arises from the side of the cricoid cartilage between the attachment of cricothyroid and the articular facet for the inferior thyroid cornu. • Thyropharyngeus arises from the oblique line of the thyroid lamina, a strip of the lamina behind this, and by a small slip from the inferior cornu. • Both cricopharyngeus and thyropharyngeus spread posteromedially to join the contralateral muscle. • Thyropharyngeus is inserted into the median pharyngeal raphe and its upper fibres ascend obliquely to overlap the middle constrictor, cricopharyngeus blends with the circular oesophageal fibres around the narrowest part of the pharynx.

48. SALPINGOPHARYNGEUS • Salpingopharyngeus arises from the inferior part of the cartilage of the pharyngotympanic tube near its pharyngeal opening and passes downwards within the salpingopharyngeal fold to blend with palatopharyngeus STYLOPHARYNGEUS • Stylopharyngeus arises from the medial side of the base of the styloid process, descends along the side of the pharynx and passes between the superior and middle constrictors to spread out beneath the mucous membrane. • Some fibres merge into the constrictors and the lateral glossoepiglottic fold, while others join fibres of palatopharyngeus and are attached to the posterior border of the thyroid cartilage.

49. SPECIAL LYMPHATIC TISSUE OF THE PHARYNX • Realize that the pharynx contains a "ring" of specialized lymphatic tissue designed to prevent the entry of pathogens into the digestive and respiratory tracts. This specialized lymphatic tissue is known as "tonsils" and is organized into three groups: • Nasopharyngeal tonsils (adenoids), located in the nasal pharynx; • Palatine tonsils (tonsils), located between the palatoglossal and palatopharyngeal folds in the oral pharynx; and • Lingual tonsils, located on the posterior surface of the tongue.