1. Upper Airway Christopher Ramnanan, Ph.D. cramnana@uottawa.ca Objectives: - Identify the following structures relating to the larynx: base of tongue, vallecula, epiglottis, aryepiglottic folds, arytenoids, true vocal cords, false vocal cords, pharyngeal walls, hypopharynx, hyoid, thyroid cartilage, cricoid cartilage, thyroid hyoid membrane. - Identify the following structures of the Nasal Cavity: Inferior, middle and superior turbinates, Septum, Mucosa, Choana, Inferior, middle and superior meati, nasal ala, nasal tip and nasal dorsum, olfactory nerve and the cribiform plate; Little's Area. - Identify and describe the three parts of the pharynx. - Describe the location and function of the adenoids, palatine tonsils and lingual tonsils, and define Waldeyer’s Ring. - Indicate the position of the true vocal cords during phonation and respiration. - List the cartilages of the larynx. - Name the nerves responsible for the motor function and sensation of the larynx. - Identify the maxillary, ethmoid, frontal and sphenoid sinuses and the drainage sites for each of the sinuses, and explain the relationship of the sinuses to the orbit and the brain

2. Air Food A musculo-membraneous tube shared by the nasal and oral cavities above and the respiratory and digestive channels below. Extends from the base of the skull to the cricoid cartilage. Widest at the hyoid bone (5 cm). Narrowest at the C6 level (1.5 cm). Note C6 as landmark: Larynx ends, trachea begins Pharynx ends, esophagus begins Pharynx: Overview C6 Cricoid cartilage

3. External Muscles of Pharyngeal Wall -Circular layer of skeletal muscle; innervated by CN X -3 components: 1) superior, 2) middle and 3) inferior pharyngeal constrictors (each with unique anterolateral origins but blend together posteriorly; difficult to distinguish them in lab) -Insertions are generally on the posterior pharyngeal raphe 1 2 3 Pterygomandibular raphe Hyoid Bone Thyroid and Cricoid Cartilages

4. Internal Muscles of Pharyngeal Wall -Longitudinal set (3) of skeletal muscles (generally innervated by CN X) -Nomenclature is indicative of superior origins/attachments: (1) salpingopharyngeus, (2) palatopharyngeus, (3) stylopharyngeus -Inferior insertion: generally blend posteriorly before attaching to posterior aspect of thyroid cartilage 1 2 3

5. Sensory Nerves of the Pharynx CN IX: oropharynx, part of nasopharynx (‘gag’ reflex) CN X: laryngopharynx (protective reflexes; cough reflex, adduction of the vocal cords) CN V 2 : nasopharynx (and part of nasal cavity)

6. Nasopharynx Oropharynx Laryngopharynx Nasopharynx  communicates w/ Nasal Cavity via the choanae; extends from sphenoid bone/occipital bone to soft palate Oropharynx  communicates w/ Oral Cavity; extends from soft palate to base of tongue/epiglottis Laryngopharynx (Hypopharynx)  communicates w/Larynx; extends from base of tongue/epiglottis to cricoid cartilage (C6) Choanae

7. Connected to base of the tongue via lateral glossoepiglottic folds and the median glossoepiglottic fold (mucosal folds) *Valleculae – small “valleys” or indentations between the folds * * Epiglottis and Base of the Tongue Epiglottis Base of Tongue Landmark Dividing Oropharynx and Laryngopharynx

8. Lymphoid Ring of Waldeyer: Ring of Tonsillar Tissue Pharyngeal (Adenoids): Posterior Roof of Nasopharynx Tubal: associated with opening of Eustachian Tube Palatine: b/w palatoglossal and palatopharyngeal arches Lingual: Base of Tongue Clinically: Tonsil enlargement can impair breathing, taste, swallowing, speaking

9. External Features of Nose Dorsum Ala Tip Root Nares Philtrum Septal Cartilage Frontal Bone Nasal Bones Lateral Cartilages Major Alar Cartilages Alar Fibrofatty Tissue Major Alar Cartilages Septal Cartilage Maxillary Bone

10. Nasal Bones/Cartilages (Internal View) Sphenoid Sinus Ethmoid Vomer Septal Cartilage Frontal Sinus 1.Septal Cartilage 2.Ethmoid Bone (Perpendicular Plate) 3.Vomer 4.Nasal Bone 5.Maxillary Bone (Nasal Crest) 6.Palatine Bone (Nasal Crest) 7.Frontal Bone (Nasal Spine) 8.Sphenoid Bone 1.Lateral wall cartilages 2.Ethmoid Bone (Superior/Middle Concha) 3.Lacrimal Bone 4.Nasal Bone 5.Maxillary Bone 6.Palatine Bone 7.Frontal Bone 8.Sphenoid Bone 1 2 3 4 5 6 7 8 Note: Inferior Concha is independent of Superior and Middle Concha 1 2 3 4 5 7 8 6

11. Respiratory Area(Inferior 2/3 rds ) lined with Respiratory Epithelium (filter, warm, humidify air) Olfactory Nerves Olfactory Bulb (CN I) Olfactory Area (Superior 1/3 rd ) lined with Olfactory Epithelium Cribriform Plate (Olfactory Bulbs sit here; olfactory nerves traverse foramina around Crista Galli) The Nasal Mucosa facilitates nasal cavity functions including: -Olfaction -Air conditioning (filtering, humidifying, warming air) -Conduit for air transport to lower respiratory tract

12. CN V 1 territory CN V 2 territory Olfactory nerve (CN I) Innervation of the Nasal Cavity (Lateral Wall Shown) CN I: Olfaction CN V: Touch Sensation in Head and Neck FYI: Nasal Mucosal Glands get their parasympathetic supply from CN VII V1V1 V2V2 V3V3

13. Blood Supply of the Nasal Cavity Kiesselbach’s (Little’s) Area: Anteroinferior septum with rich blood supply (ICA and ECA anastomoses) ICA  ethmoidal arteries ECA  sphenopalatine, superior labial, greater palatine arteries

14. Nasal Concha and Nasal Meati Superior, Middle, Inferior Concha (Turbinates) serve to funnel air into controlled path, maximizing air contact with ciliated mucosa Inferior (Largest) and Middle Concha visible from inferior view of nasal cavity Inferior and Middle Concha have been cut to reveal Inferior and Middle Nasal Meati (Inferior Meatus is largest space) Inferior Meatus Middle Meatus Superior Meatus Spheno- ethmoidal Recess

15. Paranasal Sinuses Ethmoidal Sinus (anterior, middle, and posterior sinuses) Maxillary Sinuses Frontal Sinus Sinuses decrease weight of the skull, increase capacity to humidify/filter air (lined with mucosa), can contribute to the protection of brain/eye in response to blunt force trauma Sphenoid sinus

16. Drainage of Paranasal Sinuses Sphenoid Sinus drains to spheno- ethmoidal recess Opening of maxillary sinus in Semilunar Hiatus Nasolacrimal Duct drains to Inferior Meatus Middle Meatus: Frontal Sinus, Anterior Ethmoidal Sinus, and Maxillary Sinus drain to Semilunar Hiatus Middle Ethmoidal Sinus driains to Ethmoidal Bulla Opening of Middle Ethmoidal Air Cells on Ethmoidal Bulla Posterior Ethmoidal Sinus drains to Superior Meatus Frontal Sinus

17. Hyoid Bone (C3) Thyroid Cartilage (C4/C5) Cricoid Cartilage (C6) Epiglottis Thyrohyoid membrane Cricothyroid membrane Trachea The Larynx: Cartilaginous Skeleton Arytenoid Cartilage Corniculate cartilage Not shown: Cuneiform cartilage (small structure associated with corniculates)

18. The Aryepiglottic fold Aryepiglottic mucosal folds overlies connections b/w epiglottis and arytenoid cartilage; food is directed lateral to these folds to the esophagus (pills may get lodged in the piriform recesses)

19. Organization of the Larynx Vestibule: superior to vestibular folds (false vocal cords) Glottis: sum of vocal folds (true vocal cords) + Rima glottidis (space b/w vocal folds) Infraglottic space: inferior to true vocal folds Ventricle: lateral extension of space between vestibular and vocal folds Vocal folds Vestibular folds

20. Vocal folds Vestibular folds Rima glottidis

21. Intrinsic Muscles of the Larynx The muscles that alter the length and tension of vocal folds (size and shape of the rima glottidis). Several muscles, but we will focus on two: Posterior cricoarytenoid: only muscle to abduct the vocal ligaments Cricothyroid: can be seen from anterior view; tenses the vocal folds (allowing us to change pitch)

22. Innervation of the Larynx (CN X, Vagus) Internal Br. of Sup. Laryngeal N: Sensory above the Vocal Folds (Efferent Limb of A Protective Cough Reflex) External Br. of Sup. Laryngeal N: motor to cricothyroid muscle (pitch) Superior Laryngeal N. Recurrent (Inferior) Laryngeal N: most larynx muscles (1 exception); sensory below vocal folds; may be damaged during thyroidectomy

24. Lesion to Internal Branch of Sup. Laryngeal N.? Lesion to External Branch? Lesion to Recurrent/Inferior Laryngeal N.?

25. LAB 3 CHECKLIST – UPPER AIRWAY NERVES -CN I Olfactory N. -CN V1 Opthalmic N. -CN V2 Maxillary N. -CN IX Glosspharyngeal N. -CN X Vagus N. -Superior laryngeal n. -Internal branch of superior laryngeal n. -External branch of superior laryngeal n. -Recurrent laryngeal n. MUSCLES -Superior pharyngeal constrictors -Middle pharyngeal constrictor -Inferior pharyngeal constrictor -Salpingopharyngeus -Palatopharyngeus -Stylopharyngeus -Cricothyroid -Posterior cricoarytenoid OROPHARYNX -Oropharynx boundaries -Choanae -Soft palate -Base of tongue -Epiglottis -Lateral glossoepiglottic folds -Median glossoepiglottic fold -Valleculae NB: Items italicized are conceptual, those denoted with a * are FYI ARTERIAL SUPPLY -Kiesselbach (aka Little’s) Area -Internal carotid a. -External carotid a. NASOPHARYNX, NOSE AND NASAL CAVITY -Nasopharynx boundaries -Root -Dorsum -Tip -Ala -Nares -Philtrum -Olfactory area -Respiratory area -Superior meatus -Middle meatus -Inferior meatus -Sphenoethmoidal recess -Frontal sinus -Sphenoid sinus -Ethmoid sinus -Maxillary sinus -Semilunar hiatus -Nasolacrimal duct -Ethmoidal bulla BONES AND CARTILAGE -Lateral cartilages -Major alar cartilage -Alar fibrofatty tissue -Septal cartilage -Ethmoid -Vomer -Frontal bone -Nasal bone -Maxillary bone -Palatine bone -Sphenoid bone -Lacrimal bone -Cribriform plate -Superior concha -Middle concha -Inferior concha -Hyoid bone -Thyrohyoid membrane -Thyroid cartilage -Cricothyroid membrane -Cricoid cartilage -Arytenoid cartilage -Cuneiform cartilage -Corniculate cartilage LARYNGOPHARYNX -Laryngopharynx boundaries -Trachea -Aryepiglottic fold -Piriform recesses -Vestibule -Vestibular folds -Glottis -Vocal folds -Rima glottidis -Infraglottic space -Ventricle -Pharyngeal tonsil -Tubal tonsil -Palatine tonsil -Lingual tonsil TONSILS