1. Upper Respiratory Tract

2. Lectures Objectives
Describe the structure of nasal cavity including nasal septum.
Describe the structure of lateral wall of nasal cavity including conchae and meatuses.
Locate the openings of the paranasal air sinuses and naso‐lacrimal duct in the meatuses.
Describe nasal innervations, blood supply, and its relation to epistaxis.
Study the structure of nasopharynx and associated openings with their clinical importance.
Describe the structure of various cartilages and membranes of the larynx.
Describe muscles of the larynx including their action, nerve and blood supply.
Describe the structure of vocal cords and the mechanism of voice production and control of air passageway.

3. Nose

4. Nose External nose – portion visible on face
Internal nose – large cavity beyond nasal vestibule
Internal nares or choanae
Ducts from paranasal sinuses and nasolacrimal ducts open into internal nose
Nasal cavity divided by nasal septum
Nasal conchae subdivide cavity into meatuses
Increase surface area and prevents dehydration
Olfactory receptors in olfactory epithelium

5. External Nose Parts Root Dorsum Apex
Naris (nostrils, anterior nasal apertures)
Ala

6. External Nose Skeleton of the nose
Bony part
Frontal, nasal, maxillary bones
Cartilaginous part
Lateral, septal, alar cartilages
Blood supply: branches of ophthalmic, maxillary & facial aa.
Nerve supply
Infratrochlear (V1)
External nasal (V1)
Infraorbital (V2)

8. Nasal septum Bony part Cartilaginous part ‐ Septal cartilage
Perpendicular plate of ethmoid
Vomer
Cartilaginous part ‐ Septal cartilage

9. Nasal Cavity Parts Walls of the nasal cavity Nasal vestibule
Nasal septum
Choanae (posterior nasal apertures)
Walls of the nasal cavity
Floor
Roof
Lateral wall
Sphenoethmoidal recess
Nasal conchae
Superior, middle, & inferior
Meatuses

10. Nasal Meatuses Sphenoethmoidal recess Meatuses Sphenoid sinus Superior
Posterior ethmoid sinus
Middle
Bulla ethmoidalis
Middle ethmoid sinus
Hiatus semilunaris
Maxillary sinus
Infundibulum
Frontal sinus
Anterior ethmoid sinus
Inferior
Nasolacrimal duct

11. Paranasal Sinuses
Paired cavities in ethmoid, sphenoid, frontal and maxillary bones
Lined with mucous membranes and open into nasal cavity
Resonating chambers for voice, lighten the skull
Sinusitis is inflammation of the membrane

12. Paranasal Sinuses Maxillary sinus Frontal sinus Sphenoid sinus
Between floor of orbit and roots of upper molars and premolars
Superior alveolar nn. (V2)
Frontal sinus
Supraorbital nn. (V1)
Sphenoid sinus
Body of sphenoid
Posterior ethmoidal nn. (V1)
Ethmoid sinus
Anterior, middle & posterior
Between nasal cavity and orbit
Anterior & posterior ethmoidal nn. From nasociliary n. (V1)

14. Paranasal Sinuses: X‐ray

15. Nasal Cavity: Innervation
Olfactory nerve
Trigeminal nerve
Ophthalmic…
Maxillary …

16. Nasal Cavity: Blood Supply
Anterior & posterior ethmoidal aa.
From ophthalmic a.
Sphenopalatine a.
From maxillary a.
Septal branch from facial a.
Kiesselbach’s area & plexus
Epistaxis
Lymph drainage
Deep cervical lymph nodes
Vestibule – submandibular lymph nodes

17. Pharynx

18. Pharynx Muscular tube (5 inch long) hanging from skull
Skeletal muscle & mucous membrane
Completed posteriorly & deficient anteriorly (openings into nose, mouth & larynx)
Extends from internal nares to cricoid cartilage (C6)
Funnel shape – wide superiorly & narrow inferiorly (1.5 cm)
Functions
Passageway for food and air
Resonating chamber for speech production
Tonsil (lymphatic tissue) in the walls protects entryway into body

19. Regions of the Pharynx
Distinct regions ‐‐ nasopharynx, oropharynx and laryngopharynx

20. Nasopharynx Above soft palate Openings Structures Internal nares
Pharyngeal isthmus
Auditory (Eustachian, pharyngotympanic) tube
Structures
Pharyngeal tonsil (adenoids)
Tubal elevation
Tubal tonsils
Salpingopharyngeal fold
Salpingopharyngeus m.
Pharyngeal recess

21. Oropharynx From soft palate to epiglottis Structures At floor
Posterior ⅓ of tongue
Lingual tonsils
Median glossoepiglotic fold
Lateral glossoepiglotic folds
Valleculae

22. Oropharynx At lateral wall Palatoglossal fold Oropharyngeal isthmus
Palatoglossus m.
Oropharyngeal isthmus
Palatopharyngeal fold
Palatopharyngeus m.
Palatine tonsil

23. Laryngopharynx Extends from epiglottis to cricoid cartilage
Posterior to laryngeal inlet
Piriform fossa
Between aryepiglotic fold and thyroid cartilage

24. Pharyngeal Muscles External circular muscles
Inserts into the pharyngeal raphe
Superior, middle, & inferior constrictor mm.
Overlap each other (inferior is more superficial)
Cricopharyngeus m.
Lower end
Sphincter
Internal longitudinal muscles
Stylopharyngeus m.
Palatopharengeus m.
Salpingopharyngeus m.
Nerve supply: pharyngeal plexus except stylopharyngeus muscle (IX)

26. Pharynx Sensory innervation Blood supply Lymph drainage
Nasopharynx (V2)
Oropharynx (IX)
Laryngopharynx (X) – internal laryngeal nerve
Blood supply
Ascending pharyngeal aa.
Tonsillar branch of facial aa.
Branches of maxillary & lingual aa.
Lymph drainage
Deep cervical nodes
Retropharyngeal or paratracheal nodes → deep cervical

27. Larynx Cartilage & connective tissue tube Below hyoid bone
Anterior to C4 to C6
Short passageway connecting laryngopharynx with trachea
Constructed of 3 single & 3 paired cartilages
Functions
Passageway for air
Voice production
Prevent entrance of food

28. Larynx
Relations
Infrahyoid mm.
Thyroid gland
Major blood vessels

29. Larynx: Cartilages

30. Larynx: Cartilages Thyroid cartilage The largest Incomplete ring
Laminae
Laryngeal prominence (Adam’s apple)
Oblique line
Superior & inferior cornua
Cricothyroid joints

31. Larynx: Cartilages Cricoid cartilage Arytenoid cartilages
Complete ring
Below thyroid cartilage
Lamina (posteriorly)
Cricoarytenoid joints
Arch (anteriorly)
Arytenoid cartilages
Apex, base, vocal process, & muscular process

32. Larynx: Cartilages Epiglottis Leaf shape cartilage (elastic cartilage)
Stalk – attached to thyroid cartilage
Aryepiglottic fold
Median and lateral glossoepiglottic folds
valleculae
Larynx: Cartilages

33. Larynx: Cartilages Corniculate cartilages Cuneiform cartilages
Above arytenoids (attachment of aryepiglottic fold)
Cuneiform cartilages
In the aryepiglottic fold (support)

34. Larynx: Membranes & Ligaments
Thyrohyoid membrane
Median thyrohyoid ligament
Cricotracheal ligament
Quadrangular membrane
Between epiglottis & arytenoid
Vestibular ligament (inferior margin)
Vestibular fold
Immovable, vascular (pinkish)
Cricothyroid ligament
Vocal ligament (superior margin)
Vocal fold
Mobile, avascular (whitish)
Rima glottidis (glottis)

35. Larynx: Cavity Inlet of larynx Vestibule Middle region
Orientation
Boundaries
Vestibule
Between inlet & vestibular folds
Middle region
Between laryngeal folds
Laryngeal sinus (ventricle)
Laryngeal saccule
Lower region (infraglottic cavity)
Between vocal folds & lower border of cricoid

36. Larynx: Muscles Extrinsic muscles Elevators Depressors (infrahyoid)
Suprahyoids (Digastric, stylohyoid, mylohyoid, & geniohyoid)
Longitudinal pharyngeal (stylopharyngeus, salpingopharyngeus, & palatopharyngeus)
Depressors (infrahyoid)
Sternothyroid, sternohyoid, & omohyoid

37. Larynx: Muscles Intrinsic muscles Modification of laryngeal inlet
Narrowing
Oblique arytenoid m.
Widening
Thyroepiglottic m.
Movement of vocal cords
Tensing
Cricothyroid m.
Relaxing
Thyroarytenoids (vocalis) m.
Adducting
Lateral cricoarytenoid m.
Abducting
Posterior cricoarytenoid m.
Approximating aretyneoids
Transverse arytenoid m.

38. Larynx: Muscles

40. Voice Production Vocal folds are adducted
Muscle contraction pulls elastic ligaments which stretch vocal folds out into airway
Vibrate and produce sound with released air (frequency or pitch)
Folds can move apart or together, elongate or shorten, tighter or looser
Androgens make folds thicker and longer – slower vibration and lower pitch
Quality of voice determined by other structures (mouth, lips, tongue, pharynx, soft palate, & teeth)

41. Larynx Nerve supply Blood supply Lymph drainage
Sensory innervation (X)
Above vocal cords: internal laryngeal n.
Below vocal cords: recurrent laryngeal .
Motor innervation
All intrinsic muscles innervated by recurrent laryngeal except cricothyroid muscle (external laryngeal n.)
Blood supply
Upper half: superior laryngeal branch of superior thyroid a.
Lower half: inferior laryngeal branch of the inferior thyroid a.
Lymph drainage
Deep cervical nodes