Upper Airways Presentation PDF - RCSI

Upper airways Class Year 2, Semester 1 Lecturer DR. VIJAYALAKSHMI S B Department of Anatomy Email id: [email protected] Date 25-11-2024 1  Learning Outcomes 1. Describe the oral cavity...

Upper airways Class Year 2, Semester 1 Lecturer DR. VIJAYALAKSHMI S B Department of Anatomy Email id: [email protected] Date 25-11-2024 1  Learning Outcomes 1. Describe the oral cavity and gingivae 2. Describe the tongue’s structure, blood vessels and nerves 3. Discuss the musculature and innervation of the pharynx, palate, tonsils, gag reflex 4. Describe the nose: turbinates, meatuses & sinuses 5. Identify the nasal septum & blood supply 6. Describe the structure of external ear, auditory canal & tympanic membrane 7. Describe the middle ear, ossicles, muscles & relations 8. Describe the cartilages, ligaments and muscles of the larynx 9. Describe the anatomy and movements of the vocal cords, nerve supply & injuries 10. Compare and contrast laryngotomy and tracheostomy Oral cavity Oral cavity - skeleton  Buds for permanent teeth: 8 -12 weeks of development Teeth erupt from 6 years onwards 32 permanent teeth: 2 Incisors central, lateral 1 Canine 2 Premolar 3 Molar 3rd molar/wisdom tooth ~20 years 8 teeth in each quarter *Interaction between oral epithelium & neural crest cells  Oral cavity - boundaries Mandible Hyoid bone Digastric ant. belly Mylohyoid Digastric post belly Buccinator Oral cavity – palatine tonsils Palatopharyngeal arch Palatoglossal arch Palatine tonsil Palatine tonsil  Oral cavity- Tongue Principal organ of the sense of taste An important organ of speech Assists in the mastication and deglutition of the food. situated in the floor of the mouth, within the curve of the body of the mandible Parts of the tongue: Root, Apex, Inferior Surface, Dorsum of tongue Root connected to: ▪ Hyoid by Hyoglossus, ▪ Mandible by Genioglossus, ▪ Epiglottis by Median & 2 lateral Glosso-epiglottic folds (Binding VALLECULA) and ▪ Soft palate by Palatoglossal folds TONGUE  DORSUM OF TONGUE Convex and marked by a median sulcus, divides into symmetrical halves. About 2.5 cm from the root of the organ, a depression, the foramen caecum, from which a shallow groove, the sulcus terminalis, runs lateral ward and forward on either side to the margin of the tongue. The part of the dorsum of the tongue in front of this groove, forming anterior two-thirds looks upward, rough and covered with lingual papillae Posterior third looks backward, contains numerous glands and lymphoid nodules (lingual tonsil) The foramen caecum is the remains of the upper part of the thyroglossal duct or diverticulum from which the thyroid gland is developed The Papillae of the Tongue are projections of the corium, thickly distributed over the anterior two-thirds of dorsum, giving roughness. Types of Papillae: VALLATE (Circumvallate), FILIFORM, FUNGIFORM and FOLIATE  INFERIOR SURFACE OF TONGUE This surface is connected to the floor of the mouth through frenulum Epithelium is very thin, transparent mucous membrane hence deep lingual vein can be seen through it. Lateral to the deep vein, frilly folds of sublingual epithelium – PLICA FIMBRIATA  INFERIOR SURFACE OF TONGUE Sublingual caruncle (papilla) – present on each side of the base of the frenulum that includes THE DUCT OF SUBMANDIBULAR GLAND [Wharton’s duct] The DUCTS OF SUBLINGUAL GLAND are numerous, approximately 12, open onto the crest of the sublingual fold - most medial 3 or 4 often open into the submandibular duct.  Tongue - Muscles Palatoglossus Extrinsic – connect the tongue with the skeleton Palatoglossus – supplied by the Vagus nerve (X) Styloglossus Hyoglossus – supplied by the Hypoglossal nerve (XII) Hyoglossus Styloglossus – supplied by the Hypoglossal nerve (XII) Genioglossus – supplied by the Genioglossus Hypoglossal nerve (XII) Superior longitudinal Intrinsic – Stay in the tongue Transverse & vertical all supplied by hypoglossal nerve (XII) Inferior longitudinal Superior longitudinal Inferior longitudinal Transverse Vertical  Tongue - Muscles Palatoglossus Styloglossus Hyoglossus Lingual aponeurosis Genioglossus Superior longitudinal Transverse & vertical Inferior longitudinal  MOVEMENTS OF THE TONGUE Protrusion: Genioglossus on both sides acting together Retraction: Styloglossus and hyoglossus on both sides acting together Depression:Hyoglossus and genioglossus on both sides acting together Elevation: Styloglossus and palatoglossus on both sides acting together  BLOOD SUPPLY OF THE TONGUE The main artery of the tongue is the LINGUAL BRANCH OF THE EXTERNAL CAROTID, but the TONSILLAR BRANCH OF FACIAL ARTERY AND ASCENDING PHARYNGEAL also give branches to it The veins (DEEP & DORSAL LINGUAL) open into the INTERNAL JUGULAR vein  NERVE SUPPLY ALL THE GLOSSI ARE SUPPLIED BY XII EXCEPT PALATOGLOSSUS (PHARYNGEAL PLEXUS)  NERVE SUPPLY The sensory nerves of the tongue are: (1) the lingual branch of the mandibular forms the nerve of general senses for the anterior 2/3rd (2) the chorda tympani branch of the facial, which runs in the sheath of the lingual, is the nerve of taste for the anterior 2/3rd (3) the glossopharyngeal carries both taste and general senses of the posterior 1/3rd (4) the superior laryngeal branch of the Vagus sends some fine branches to the root near the epiglottis (both general & taste) LINGUAL NERVE  The preganglionic secretomotor fibers arise from superior salivatory nucleus in the pons and then pass successively through the sensory root of facial, chorda tympani and lingual nerves and reach submandibular ganglion Postganglionic fibers supply directly the submandibular gland and sublingual gland through lingual nerve  Oral cavity - Innervation MOTOR NERVES INVOLVED: Mandibular nerve: Mastication muscles, Mylohyoid, Anterioe belly of digastric, Tensor palati, Tensor tympani Vagus: Palatoglossus Hypoglossal: Intrinsic muscles of the tongue, Hyoglossus, Styloglossus, Genioglossus Anterior ramus of C1 (carried by the hypoglossal nerve): Geniohyoid Facial: Buccinator SENSORY NERVES INVOLVED: Mandibular nerve: General sensory of lower and lateral oral cavity: gingivae, teeth, cheeks, lips, and anterior tongue Maxillary nerve: General sensory of the upper oral cavity: gingivae, teeth, lips, Facial nerve: Taste of the anterior tongue Glossopharyngeal: Taste and general sensory of most of the posterior tongue Vagus: Taste and general sensory of a small part of the posterior tongue  External Nose ⚫ Root ⚫ ⚫ Bridge ⚫ Apex ⚫ ⚫ Ala ⚫ ⚫ ⚫ ⚫ Nostril Parts: Root, Apex, Bridge, Ala, Nostril  External Nose Skeletal framework- bone and hyaline cartilage Nasal Maxilla Lateral cartilages Septal cartilage Alar cartilages Bones: Nasal, Maxilla, nasal part of frontal Cartilages: bone & its nasal spine Septal, Alar, Lateral cartilages  External Nose Nasal part of Frontal bone Skeletal framework: Bone and cartilage  BOUNDARIES Medial wall- partly bony and partly cartilaginous septum. Formation: perpendicular plate of ethmoid, vomer and anteriorly by septal cartilage. Roof-nasal spine of frontal bone, cribriform plate of ethmoid and sphenoid Fracture: CSF rhinorrhea  BOUNDARIES Floor- upper surface of hard palate. Palatine process of maxilla + horizontal plate of palatine bone Lateral wall- formed by 3 curved bony projections called nasal conchae or turbinates Nasal cavity lateral and medial wall Nasal Cavity: Lateral Wall  Nasal Cavity: Lateral Wall (Openings) Middle meatus middle ethmoidal Superior meatus group opening posterior ethmoidal group opening frontal sinus opening Sphenoethmoidal recess through infundibulum sphenoidal sinus opening anterior ethmoidal group opening maxillary sinus opening Inferior meatus nasolacrimal duct opening  Nasal Cavity 3 regions: Olfactory Vestibule ◼ dilated space internal to the nostril. ◼ lined by skin with hairs (vibrissae). ◼ traps/removes particles from airway. Respiratory ◼ lower 2/3 of cavity. ◼ lined by pseudo stratified ciliated columnar epithelium ◼ adjusts temperature/humidity of respired air. Olfactory ◼ roof and upper 1/3 of cavity. Respiratory ◼ lined by olfactory epithelium. Vestibule ◼ sense of smell.  Respiratory and olfactory mucosa ◼ Olfactory nerves ◼ Trigeminal nerve (Ophthalmic and Maxillary divisions)  Nasal Cavity (Lateral wall): Arterial Supply Branches of ophthalmic artery (internal carotid artery) Anterior ethmoidal a. ◼ Anterior ethmoidal artery Posterior ethmoidal a. ◼ Posterior ethmoidal artery Sphenopalatine a. Branches of external carotid artery ◼ Sphenopalatine artery Maxillary ◼ Greater palatine artery artery ◼ Facial artery ⚫ Superior labial artery ⚫ Lateral nasal artery Lateral nasal a. Greater palatine a.  Nasal Septum: Arterial Supply From Ophthalmic A. (internal carotid) “Kieselbach’s area” Little’s Area ◼ Anterio-inferior part of nasal septum ◼ About 1.5cm from nostril. ◼ Common site of epistaxis. From Maxillary A. (external carotid) https://www.earthslab.com/anatomy/nasal-cavity/  Nasal Cavity: Venous drainage Submucosal venous plexus – drains into the sphenopalatine, facial & ophthalmic veins Importance? Venous drainage of external nose – into Facial vein- communicates with cavernous sinus (dural venous sinus) “Dangerous area”  Paranasal Sinuses Frontal sinus superior orbital fissure Frontal sinus Ethmoidal sinus Maxillary sinus septum nasal ◼ Air-filled extensions of (roof and lateral wall of) nasal cavity. ◼ Erode into surrounding bones (frontal, sphenoid, ethmoid, maxillary) during childhood and early adulthood  Paranasal Sinuses ethmoidal cells frontal sinus frontal sinus Frontonasal duct opening sphenoidal sinus maxillary sinus opening maxillary sinus maxillary sinus opening sphenoidal sinus opening ◼ The air-containing sacs are lined by ciliated epithelium. ◼ Communicate with/drains into the nasal cavity via narrow channels.  Paranasal Sinuses frontal sinus F S E maxillary sinus opening M maxillary sinus Functions: ◼ For resonance ◼ Lighten the skull bone ◼ Warm/moisten the air  Paranasal Sinuses Frontal sinus: Ethmoidal sinus: ◼ Triangular-shaped. ◼ 8-10 air cells. ◼ Within frontal bone. ◼ Within ethmoid bone ◼ Drains into ◼ Drainage: middle meatus through Ant group - middle meatus (infundibulum) a frontonasal duct into Middle group - middle meatus/ the infundibulum. ethmoidal bulla Posterior group – Superior meatus Sphenoidal sinus: ◼ On each side of midline. Maxillary sinus: ◼ Within body of sphenoid bone ◼ Pyramidal-shaped. ◼ Drains into sphenoethmoidal recess. ◼ Within the cavity of maxilla ◼ Drains into middle meatus (hiatus semilunaris)  Relevance To Clinical Practice maxillary sinus opening Orbit frontal sinus ethmoidal cells Orbit inferior maxillary sinus conchae roots of upper molars ◼ Infection of paranasal sinuses (Sinusitis) may be due to: ⚫ complication of nasal infections. ⚫ extension from dental abscess.  Relevance To Clinical Practice maxillary sinus opening Orbit frontal sinus ethmoidal cells Orbit inferior maxillary sinus conchae roots of upper canine molars fossa Maxillary sinus: Drainage: ⚫ roof related to orbit. ◼ Postural drainage. ⚫ floor related to roots of upper molars. ◼ Enlarge the size of ostium. ⚫ ostium opens at higher level than floor ◼ Open through inferior meatus or canine fossa of maxilla.  Relevance To Clinical Practice Frontal sinus frontal lobe pituitary gland Orbit Ethmoid Orbit sinus Frontonasal duct sphenoidal opening sinus Optic nerve sphenoidal sinus opening Ethmoidal sinusitis: ⚫ Can spread to the orbit ? ⚫ Can affect the optic nerve? (esp. posterior ethmoid group) Approach pituitary gland via nasal cavity and sphenoidal sinus.  Pharynx Funnel-shaped muscular organ covered by mucosa: Nasopharynx, Oropharynx and Laryngopharynx. Attached to the base of the skull by pharyngobasilar fascia and located on the back of nose, mouth and larynx. Three constrictor muscles on each side that meet posteriorly on the midline (raphe). Three elevator muscles that attach on the eustachian tube, styloid process and soft palate. The elevators merge with the constrictors.  Nasopharynx Oropharynx Laryngopharynx Nasopharynx Oropharynx Laryngopharynx NASOPHARYNX Tubal elevation Auditory tube (Pharyngotympanic tube) Salpingopharyngeal fold a vertical fold of mucous membrane. It covers the salpingopharyngeus muscle, which opens the pharyngeal orifice of the pharyngotympanic tube during swallowing The pharyngotympanic (Eustachian/Auditory) tube connects the tympanic cavity to the nasopharynx and allows the passage of air between these spaces to equalize the air pressure on both aspects of the tympanic membrane. Has cartilaginous & bony parts OROPHARYNX Palatoglossal arch Palatine tonsil Palatopharyngeal arch  PHARYNX- SEEN FROM BEHIND Nasopharynx Oropharynx Laryngopharynx Piriform fossa  PHARYNGEAL MUSCLES Three constrictors: superior – middle – inferior Three elevators: Salpingopharyngeus Stylopharyngeus Palatopharyngeus  Pharynx - Blood and nerve supply Arterial Supply: Mainly branches of external carotid - lingual, maxillary artery. Lower part from inferior thyroid artery - Thyrocervical trunk – Subclavian artery Venous drainage: Pharyngeal veins form a plexus which drains into pterygoid plexus, facial and internal jugular vein Motor Nerve supply: innervated by pharyngeal plexus of nerves that is formed by pharyngeal branches of VAGUS & GLOSSOPHARYNGEAL NERVES and sympathetic branches Glossopharyngeal: Stylopharyngeus Vagus: all other muscles Sensory Nerve supply: Glossopharyngeal: most of the sensory supply Vagus: Anterior surface of the epiglottis (general sensory and taste) laryngopharynx via (visceral sensory) Maxillary: part of the nasopharynx  PALATE Forms roof of mouth and floor of nasal cavities Two parts – Hard palate anteriorly Covered with periosteum and oral mucosa (inferiorly) and respiratory mucosa superiorly  Two parts Hard palate anteriorly Soft palate posteriorly  Anatomical features related to soft palate – Arches Join soft palate to tongue and pharynx Palatoglossal arch – Mucosal fold – Contains palatoglossus muscle Palatopharyngeal arch – Mucosal fold – Contains palatopharyngeus muscle Form anterior and posterior boundaries of tonsillar fossa on either side Tonsillar fossae Contain palatine tonsils  Muscles Nasal septum Eustachian of the soft tube palate, seen from TENSOR behind PALATI LEVATOR PALATI Medial pterygoid Pterygoid plate hamulus UVULAR MUSCLE Uvula ORAL CAVITY PALATOPHARYNGEUS  Functions of the muscles of the soft palate TENSOR PALATI tenses the soft palate. This occurs during swallowing, when the tongue forces the bolus of food against the tensed soft palate, directing it into the oropharynx. LEVATOR PALATI can elevate the soft palate against the back wall of the nasopharynx, shutting off the nasal cavity from the pharynx when we swallow or cough, and in speaking when we pronounce some letters (B, P). This closure is assisted by contraction of some of the fibres in the SUPERIOR CONSTRICTOR of the pharynx. Contraction of the UVULAR MUSCLES thickens and shortens the uvula, helping to produce an airtight seal in closing off the nasopharynx. PALATOGLOSSUS draws the tongue against the soft palate, sealing off the mouth from the oropharynx. PALATOPHARYNGEUS pulls pharynx superiorly and anteriorly during swallowing  INNERVATION Sensory from branches of: Maxillary nerve (V2) through pterygopalatine ganglion; Glossopharyngeal nerve supplies the region of the soft palate Motor Tensor veli palatini innervated by a branch of the Mandibular nerve All the others are innervated by the Vagus nerve  Testing for palatal elevation and the gag reflex Asking a patient to say “Aaaah” will produce a symmetrical elevation of the soft palate if the vagus nerves are functioning properly. Touching the soft palate or any part of the pharynx (e.g. with a mouth mirror) triggers the GAG REFLEX. This reflex is protective and prevents things from entering the pharynx except during normal swallowing Elicited by touch stimulus on the pharynx Evokes muscle contraction at the base of the tongue and122/uiconf_id/44640261/entry_id/0_8oeftziy/embed/dynamic? https://www.kaltura.com/index.php/extwidget/preview/partner_id/816 the pharyngeal wall Touch back of the pharynx with tongue depressor and observe the elevation of the palate Afferent limb Glossopharyngeal (IX): inputs to the nucleus solitarius and the spinal trigeminal nucleus Efferent limb Vagus (X): from the nucleus ambiguus  Swallowing Close nasopharynx – Elevate soft palate by Levator & Tensor Palati & lower fibres of palatopharyngeus) Open pharyngotympanic tube – Levator palati Close larynx – Larynx lifted up by mylohyoid, stylohyoid & digastric – Epiglottis falls down Open oesophagus – Cricopharyngeus opens – NB Killian’s dehiscence between thyropharyngeus and cricopharyngeus Larynx and hyoid bone  Larynx Cartilagnous structure + ligaments and muscles Internal lining by tunica mucosa Location in the neck Caudal to hyoid bone (connected by thyrohyoid ligament) Cranial to the trachea (connected by crico-tracheal ligament) Upper margin of the Larynx C5 Upper margin of the Trachea C6-C7  Larynx cartilages and ligaments Arytenoid cart. Epiglottis cart. Corniculate cart. Hyoid bone Arytenoid cart. Corniculate cart. Thyro-hyoid lig. Thyroid cart. Crico-thyroid lig Crico-thyroid joint Cricoid cart. Crico-tracheal lig. Cricoid cart. Trachea  Larynx cartilages and ligaments Epiglottis cartilage Hyoid bone Thyro-hyoid lig. Thyroid cart. Corniculate Crico-thyroid lig Arytenoid cart. Crico-thyroid joint Cricoid cart. Vocal ligament Crico-tracheal lig. Trachea  Vocal folds Epiglottis cartilage Aryepiglottic fold Thyrohyoid lig. Thyroid cartilage Corniculate Arytenoid cart. Vestibular fold Ventricle between the folds Vocal ligament Vocal fold Larynx internal surface The space between the right and left vocal folds is the Glottis (narrowest spot)  Larynx Muscles of Larynx Extrinsic Intrinsic Elevators Constrictor of Inlet ◼ Geniohyoid ◼ Oblique arytenoid, Aryepiglottic ◼ Stylohyoid ◼ Mylohyoid Dilator of Inlet ◼ Digastric ◼ Thyroepiglottic ◼ Stylopharyngeus Regulators of Vocal Cord ◼ Salpingopharyngeus ◼ Posterior cricoarytenoid (abduct) ◼ Palatopharyngeus ◼ Lateral cricoarytenoid (adduct) Depressors ◼ Transverse arytenoid (approximates) ◼ Omohyoid ◼ Thyroarytenoid, Vocalis (relax) ◼ Sternohyoid ◼ Cricothyroid (tense) ◼ Sternothyroid ◼ Thyrohyoid Larynx- Intrinsic muscles Thyroepiglottic Thyroarytenoid Lateral Cricoarytenoid Larynx- Intrinsic muscles Posterior Crico-arytenoid Transverse arytenoid Lateral Crico-arytenoid Thyro-arytenoid Vocalis Cricothyroid  Posterior cricoarytenoid Note: Posterior crico-arytenoid is the only ‘abductor’ of the vocal folds (“Life saving muscle”)  Lateral cricoarytenoid Adduction of inter-membranous part  Transverse arytenoid Adduction of inter-cartilaginous part  Abduction & Adduction 1 Posterior cricoarytenoid stembanden_axial_2m (Abduction) 2 Lateral cricoarytenoid (Adduction of intermembranous part) 3 Transverse arytenoid (Adduction of intercartilagenoius part) Relaxers & Tensors of Vocal ligaments opzij_new_m_optimized Thyroarytenoid and Vocalis Relax and shortens vocal cord Cricothyroid and partly by vocalis tenses the vocal cord  Larynx- Nerve supply superior laryngeal internal nerve laryngeal superior laryngeal nerve nerve external left vagus nerve laryngeal nerve right recurrent left recurrent laryngeal laryngeal nerve nerve right subclavian artery left vagus Right vagus cricothyroid ligamentum arteriosum All the intrinsic muscles of larynx are supplied by recurrent laryngeal nerve except the cricothyroid which is supplied by external laryngeal nerve  Larynx- Nerve supply Sensory Mucous membrane Internal laryngeal branch of above vocal fold level superior laryngeal branch of vagus nerve Mucous membrane Recurrent laryngeal nerve branch of below vocal fold level vagus nerve Motor Intrinsic muscles Recurrent laryngeal nerve branch of (all except cricothyroid) vagus nerve Cricothyroid External laryngeal branch of superior laryngeal branch of vagus nerve  Nerve supply VAGUS Superior laryngeal Recurrent laryngeal [Mixed] Internal laryngeal External laryngeal Sensory Motor [Sensory] [Motor] Below the All muscles Vocal folds Except Cricothyroid Above the Cricothyroid Vocal folds Secreto Motor  Larynx- Blood supply Arterial supply Superior laryngeal branch of superior thyroid artery Upper ½ of larynx (accompanied by internal branch of superior laryngeal nerve) Inferior laryngeal branch of inferior thyroid artery Lower ½ of larynx (accompanied by recurrent laryngeal nerve) Venous drainage Superior laryngeal vein joins superior thyroid vein & Upper ½ of larynx through it drains into the Internal jugular vein Inferior laryngeal vein joins inferior thyroid vein, which Lower ½ of larynx empties into the left brachiocephalic vein First drains to regional nodes (infrahyoid, prelaryngeal, pre/paratracheal) Lymphatic Drainage - then eventually drains into deep lateral cervical nodes Above the vocal cord Upper deep cervical nodes Below the vocal cord Lower deep cervical nodes  Superior laryngeal artery and Internal laryngeal nerve External carotid artery Superior thyroid artery Inferior laryngeal artery and Recurrent laryngeal nerve Inferior thyroid artery Thyrocervical trunk Intrinsic muscles of the Larynx  Ear The ear is composed of inner, middle and external ear portions External ear -auricle - external auditory meatus -tympanic membrane Middle ear - malleus, incus & stapes - auditory tube Internal ear - cochlear duct - semicircular canal Ear Ear Canal 2.5 cm Tympanic membrane  Auditory Ossicles Auditory ossicles (malleus, incus and stapes) form a mobile chain of small bones across the tympanic cavity from the tympanic membrane to the oval window. Tendon of tensor tympani inserts into the handle of the malleus. Chorda tympani nerve crosses the medial surface of the neck of the malleus Base of the stapes fits into the oval window on the medial wall of the tympanic cavity. Two muscles dampen or resist movements of the ossicles, one also dampens movements (vibrations) of the tympanic membrane – Tensor tympani and Stapedius Middle ear Middle ear FACIAL NERVE AND MIDDLE EAR  Internal Ear Contains the vestibulocochlear organ Present in the petrous part of the Temporal bone Consists of: Bony labyrinth – has series of bony cavities – cochlea, vestibule, and the three semicircular canals Membranous labyrinth – has series of communicating sacs and ducts, suspended in the bony labyrinth  Bony labyrinth Vestibule – central part of the bony labyrinth separated from the middle ear by the oval window Saccule Utricle Cochlear duct Semicircular ducts Round window separates the middle ear from the scala tympani (part of the cochlear duct)  Membranous labyrinth Ventral cochlear region Saccule Cochlear duct Utricle Semicircular Endolymphatic canals duct  Bony labyrinth Membranous labyrinth  References Gray’s Anatomy for Students Acknowledgement Practice questions Google images http://teachmeanatomy.info/