Upper Respiratory Tract Anatomy PDF

GROSS AND CLINICAL ANATOMY UPPER RESPIRATORY TRACT TERM 1 | SHIFT 2 | OCTOBER 18, 2024 | Milabelle B. Lingan, MD, FPSO-HNS, MHM TABLE OF CONTENTS 1. NOSE MTM 1. NOSE 1.1. External Nose 1.2. External Nose: Muscles 1.3. Ex...

GROSS AND CLINICAL ANATOMY UPPER RESPIRATORY TRACT TERM 1 | SHIFT 2 | OCTOBER 18, 2024 | Milabelle B. Lingan, MD, FPSO-HNS, MHM TABLE OF CONTENTS 1. NOSE MTM 1. NOSE 1.1. External Nose 1.2. External Nose: Muscles 1.3. External Nose: Sensory Innervation 1.4. External Nose: Blood Supply 1.5. Internal Nose: Nasal Cavity 1.6. Clinical Anatomy: Eustachian Tube Dysfunction and Otitis Media 1.7. Clinical Anatomy: Nasal Foreign Body 2. BOUNDARIES OF THE NASAL CAVITY 2.1. Nasal Cavity: Medial Wall (Nasal Septum) 2.1.1. Clinical Anatomy: Septal Deviation 2.2. Nasal Cavity: Lateral Wall 2.2.1. Endoscopic Visualization of the Nasal Cavity 2.3. Internal Nose: Blood Supply 2.3.1. Clinical Anatomy: Epistaxis 2.4. Internal Nose: Venous and Lymphatic Drainage Fig 1. The Nose 2.4.1. Clinical Anatomy: Nasal Vestibulitis (PowerPoint slides of Dr. Lingan) 2.5. Internal Nose: Nerve Supply 2.5.1. Clinical Anatomy: Allergic Rhinitis Functions: 3. PARANASAL SINUS ○ Passage of air to the lungs 3.1. Functions ○ Cleanses and conditions the inspired air 3.2. Clinical Anatomy: Sinusitis ○ Contains the nerves for olfaction/smell 4. LARYNX The nose begins from the entrance to the nasal 4.1. Internal Structures of the Larynx vestibule at the nares (nostril) posteriorly to the 4.1.1. Lining Epithelium posterior choanae. 4.1.2. Divisions The nasopharynx is part of the upper airway 4.1.3. Indirect Laryngoscopy Stridor: abnormal breath sound that happens when 4.1.4. Flexible Laryngoscopy there is a narrowing within the respiratory tract 4.2. Cartilaginous Framework 4.3. Landmarks 1.1. External Nose MTM 4.4. Laryngeal Joints 4.5. Laryngeal Membranes and Ligaments 4.6. Laryngeal Folds EXTERNAL NOSE 4.7. Extrinsic Laryngeal Muscles 4.8. Intrinsic Laryngeal Muscles 4.9. Innervation of Intrinsic Laryngeal Muscles 4.10. Blood Supply of the Larynx 4.11. Venous Drainage of the Larynx 4.12. Lymphatic Drainage of the Larynx 4.13. Clinical Anatomy: Vocal Fold Mass 4.14. Clinical Anatomy: Laryngeal Edema 4.15. Clinical Anatomy: Vocal Fold Paralysis 5. SUMMARY LEGEND Reference Book Verbatim Fig 1.1 External Nose Previous Trans Take Note / Important Info (PowerPoint slides of Dr. Lingan) Page 1 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 The external nose is attached to the forehead by Review the root or bridge of the nose. It has 2 elliptical external orifices called nostrils or nares. The lateral margins of the nares are rounded or mobile, called ala nasi. BONY FRAMEWORK Fig 1.2 External Nose: Bony Framework (PowerPoint slides of Dr. Lingan) Frontal bone Nasal bone Frontal process of the maxilla Bony nasal septum CARTILAGINOUS FRAMEWORK Fig 1.4. Bony and Cartilaginous External Nose ★ Nasal part of frontal bone 1 Nasal bone 2 Frontal process of the maxilla bonyIchilaginosa carity 3 Upper lateral cartilage 5 Lower lateral cartilage Fig 1.3 External Nose: Cartilaginous Framework (PowerPoint slides of Dr. Lingan) Nasal cartilage: plates of cartilage that make up 1.1.1. Nasal Bone the majority of the external nose. Upper lateral cartilage Lower lateral cartilage ○ Lateral crus ○ Medial crus Nasal septum: contributes to both external nose and nasal cavity. ○ Has bony and cartilaginous parts. ○ Divides the nasal cavity into the left and right side Fig 1.5. A radiograph showing soft tissue lateral of the Page 2 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 nose x ray with a displaced fracture of the nasal bone. force After a blow to the nose, whether frontal or lateral, Nasal Prominence makes the nasal bone the most patients would always present with epistaxis and commonly fractured facial bone with low impact external nasal deformity 1.1.2. Muscles Fig 1.6. The muscles of the external nose Muscle Origin Insertion Nerve Action Levator (Quadratus) Upper frontal process Skin of upper lip and Widens nostrils, elevates Labii Superioris of the maxilla nostrils upper lip → snarl expression Alaeque Nasi Nasalis Frontal process of Aponeurosis of the Compresses the mobile nasal (Compressor naris) maxilla bridge of the nose cartilage Dilator Naris Facial Nerve (Anterior and Maxilla Ala of the nose Widens the nasal aperture (CN 7) Posterior Parts) Skin between the Procerus Nasal bone Wrinkles the skin of the nose eyebrows Nasal septum and Incisive fossa Depressor Septi back part of the ala of Depresses the nasal septum of maxilla the nose 1.1.3. Sensory Innervation 1.2. External Nose: Blood Supply Trigeminal Branches Areas Nerve Division Ophthalmic Infratrochlear Bridge and crest (CN V1) External of the nose Nasal Maxillary Infraorbital Lateral sides of (CN V2) the nose Fig 1.7. Blood supply of the external nose Page 3 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 Blood supply to the external nose comes from both 1.3.1 Two Portions of the Nasal CavityIBM the internal and external carotid arteries. PORTIONS OF THE NASAL CAVITY External Nose Blood Supply Areas Origin Branches Supplied Infratrochlear skin of the ICA Ophthalmic a. Dorsal Nasal dorsum and side walls of Maxillary a. Infraorbital the nose skin of the ala Alar ECA Septal Facial a. lower part of Lateral Nasal the nasal Angular septum Fig 1.9. Two portions of the nasal cavity 1.3. Internal Nose: Nasal CavityIBM Red circle: Opening of the eustachian tube Narrow vault-shaped area at the NASAL CAVITY attic or superior portion of the Olfactory nasal cavity (blue area) Portion Lined by yellowish mucosa Supplied by non-myelinated nerve filaments of the olfactory nerve Wider area where the mucosa is glandular, thicker, and Respiratory permeated by rich vascular Portion network (outside the blue area and bounded by broken lines) Fig 1.8. Parts of the nasal cavity Extends from nostril to the 1.3.2. Eustachian Tube DysfunctionIBM Nasal Cavity posterior nasal aperture (posterior choanae) EUSTACHIAN DYSFUNCTION & OTITIS MEDIA Where the nose opens into the Posterior Nasal nasopharynx → part of the Choanae pharynx posterior to the nose Opening is visible near the Eustachian Tube posterior choanae Area of nasal cavity lying just inside the nostril ★ Nasal Bordered by the ala Vestibule contains vibrissae (hair) inside the nostril Entrance to the middle ★ Atrium meatus Superior to the vestibule Fig 1.10. Eustachian dysfunction and otitis media Eustachian The opening on the nasal side is Page 4 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 Tube located close to the posterior 2. BOUNDARIES OF THE NASAL CAVITY JZM choanae. The end of the tube also opens at ROOF the floor of the middle ear. Responsible for middle ear Anterior Nasal and frontal bone beneath the nose ventilation and pressure equalization. Middle Cribriform plate of ethmoid bone beneath the anterior cranial fossa Dysfunction causes negative pressure in the middle ear, and Posterior Sphenoid (downward sloping body of edema and inflammation of the sphenoid sinus) mucosa. Dysfunction Fluid accumulation behind the eardrum → middle ear effusion WALLS (lower right photo) Tympanic membrane retraction or 3 bony projections called conchae/ perforation Lateral turbinates Wall Inferior to each concha is a meatus Obstruction by enlarged adenoid or tumor Middle ○ The adenoids are tonsil-like Nasal septum Wall structure located in the nasopharynx; when enlarged, it covers the opening of the FLOOR Causes of eustachian tube ETD Stenosis due to inflammation Also corresponds to the superior surface of the (URTI) hard palate: Deficient active opening by tensor Palatine process of the maxilla veli palatini muscle Horizontal plate of palatine bone In cases such as cleft palate patients 2.1. MEDIAL WALL (NASAL SEPTUM) JZM 1.3.3. Nasal Foreign BodyIBM MEDIAL WALL (NASAL SEPTUM) NASAL FOREIGN BODY Fig 1.11. Foreign body in the nasal cavity Fig 2.1. Medial wall of the nasal cavity Unilateral foul-smelling purulent Also known as the septal Presentation rhinorrhea which may mask the Quadrangular cartilage foreign body. Cartilage Forms the anterior part of the septum Suctioning of secretion and extraction Treatment of foreign body (to prevent Also known as the infection/ulceration of nasal mucosa) perpendicular plate of the Vertical Plate, ethmoid Ethmoid Forms the upper portion of the posterior part of nasal septum Page 5 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 Makes up the lower part of the bony 2.2. LATERAL WALL SLM Vomer nasal septum COMPONENTS OF THE LATERAL WALL Most inferior part of the septum Forms part of the floor of the nasal cavity Nasal Crest A crest of bone formed by the maxilla anteriorly and palatine bone posteriorly 2.1.1. Septal Deviation SEPTAL DEVIATION Fig. 2.3.1. Lateral nasal wall with intact mucosal lining Fig 2.2. Presentation of septal deviation Trauma to cartilaginous septum such as during childbirth, frequent manipulation or rubbing of the nose Deformity due to physical injury Cause Fig. 2.3.2. Lateral wall, devoid of mucosal lining which came from fracture to the cartilaginous septum ○ Fractured elements tend to override and block the nasal cavity, usually unilaterally. Unilateral nasal obstruction Worsened by upper respiratory tract infection or acute rhinitis Presentation ○ Due to the congestion of turbinates aggravating the obstruction Patients that cannot protect the Fig. 2.3.3. Conchae covered by soft tissue and airway during feeding would mucosa require a nasogastric tube insertion. Contains 3 projections of bone: Relevance ○ Superior concha ○ Inspect for septal deviation to lessen the discomfort and ○ Middle concha Bony prevent trauma during ○ Inferior concha Projections nasogastric tube insertion Occasionally, there can be a supreme concha found above the superior concha 2.1.2. Nasogastric tube (NGT) insertion For patients that would require feeding through a Space below each turbinate: / conchae nasogastric tube, the tube must be inserted ○ Superior meatus Meatus through the nostril that is wider ○ Middle meatus ○ Inferior meatus Page 6 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 Spheno- Maxillary sinus ethmoidal Small area above the superior concha Hiatus semilunaris Recess Infundibulum Uncinate process Ethmoid bulla ☛ “Conchae and turbinates were used interchangeably in the lecture. But strictly speaking, conchae refers to the Nasolacrimal duct bone, while turbinates refer to the mucosa-covered That is why when you bone.” (Obnamia, 2022, through subsec D1) Inferior Meatus cry, you also have watery nasal discharge When the choncha is lined by mucosa, it is called turbinate. But for your level, it can be interchangeable. (2023) 2.2.1. Sphenoethmoidal Recess ORIFICES IN THE LATERAL WALL SPHENOETHMOIDAL RECESS Fig. 2.4.1. Lateral nasal wall and conchae in a cadaveric specimen Fig. 2.5. Probe pointing at the Sphenoethmoidal Recess Small area found above the superior concha Anterior to the ostium of the sphenoid sinus ○ Receives the opening of this sphenoid sinus ○ The ostium of sphenoid sinus drains into the sphenoethmoidal recess The space superior to the superior turbinates 2.2.2. Superior Meatus Fig. 2.4.2. Lateral nasal wall, conchae partially SUPERIOR MEATUS removed to show the openings located on each meatus Serves as the drainage of the nose Each orifice has specific contents Sphenoethmoidal Sphenoid sinus Recess Superior Meatus Posterior ethmoid Frontal sinus Middle Meatus Anterior ethmoid sinus Fig. 2.6. Probe pointing at the Superior Meatus Page 7 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 Lies below the superior concha ethmoidalis middle ethmoidal sinuses Space below superior turbinates Opens on its upper border Receives openings from the posterior ethmoid sinuses Hiatus Curved opening in middle semilunaris meatus Space between the bulla and M 2.2.3.* iddle Meatus Superior ethmoid Bulla uncinate process: Lies below the middle concha Hiatus semilunaris ○ Below the ethmoid bulla Uncinate ○ Superior to the uncinate #middle process SUPERIOR. MEATUS Space in front of the ethmoidal bulla (bulla ethmoidalis) Uncinate process is the anterior lip/part of hiatus semilunaris Infundibulum Anterior end of hiatus semilunaris Funnel-shaped channel Continuous with the frontal sinus Leads to opening of the frontal Fig. 2.7.1. Lateral Wall of the Nasal Cavity sinus Maxillary Opens directly into middle meatus sinus by the hiatus semilunaris Ostium Opening of the maxillary sinus found within the hiatus semilunaris 2.2.4. Inferior Meatus Lies below the inferior concha Receives the opening of the lower end of the nasolacrimal duct Guarded by a fold of mucous membrane 2.2.5. Endoscopic Visualization of the Nasal Cavity Procedure to evaluate patients with nasal complaints (http://drrahmatorlummc.com) ENDOSCOPIC VISUALIZATION OF NASAL CAVITY Entering the vestibule 1 Hairy part of the nostril Fig 2.7.2. Lateral Wall of the Right Nasal Cavity Image B: The superior, middle, and inferior conchae has been partially removed to show the openings of the paranasal sinuses and the nasolacrimal duct Bulla Rounded swelling formed by the Page 8 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 Elevation of the soft palate Floor of the nose Patient is asked to say “K” to see the 2 To the left is the 6 elevation inferior turbinate To the left is the opening of the eustachian tube Opening of the sphenoid sinus at the Middle turbinate sphenoethmoidal recess 3 Lateral to this would 7 be the middle Probe was directed meatus superiorly, 30 degrees into the cavity JAM 2.3. INTERNAL NOSE: BLOOD SUPPLY Uncinate process (left structure) Origin Branches Areas Supplied 4 I Ophthalmic Anterior Anterior and middle Portion of bulla C a. Ethmoid a. ethmoidal sinuses ethmoidalis is seen inside (where the A Frontal sinus pointer is) Lateral nasal wall Nasal septum Posterior Posterior ethmoidal Wall of the Ethmoid a. sinuses nasopharynx Dura and nasal cavity Probe was inserted E Internal Spheno Large portion of the perpendicular to the Maxillary a. palatine a. 5 floor of the nose C nasal cavity A Most important** until the posterior choana Greater Hard palate mucosa Palatine a. Gingival tissue To the left is the Palatine tonsils opening of the Eustachian tube Facial a. Superior Upper lip, including its Labial a. labial glands, mucous membranes and muscles Located lateral to the septum Page 9 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 KIESSELBACH'S PLEXUS ANTERIOR EPISTAXIS Little’s Area Located in the anteroinferior portion of the septum Most common location of epistaxis (nasal Where the sphenopalatine artery anastomoses vestibule) with the superior labial artery of the facial artery Occurs of the anteroinferior portion of the septum and the greater palatine artery of internal at Keisselbach’s plexus and involves the septal maxillary artery branches of the sphenopalatine and facial Common area for epistaxis or nasal bleeding vessels from injuries secondary to nose picking or turbulence of passing air during excessive nose Picking one’s nose blowing Allergic rhinitis Causes Upper respiratory tract infection Blowing one’s nose forcibly 2.3.1. Epistaxis POSTERIOR EPISTAXIS CASE 1: EPISTAXIS Less common Bleeding that trickles down the throat A 12-year-old boy was brought for consultation due to ○ Blood from the nose back-flowing into the recurrent epistaxis that resolves spontaneously. There throat was no associated fever, cough, or cold. The patient is Presents as bloody cough fond of picking his nose. Physical examination ○ BUT the source is from the nasal area revealed minimal blood clots on the medial wall of the Usually seen in adults with uncontrolled elevated left nasal cavity. blood pressure From Woodruff’s plexus and involves the internal maxillary artery 2.4. INTERNAL NOSE: VENOUS & LYMPHATIC DRAINAGE Anterior 2.4.1. Venous Drainage VENOUS DRAINAGE OF INTERNAL NOSE Posterior Fig. 2.8. Anterior (A) and posterior (B) epistaxis Structure involved Nasal septum Fig. 2.9. Venous drainage of the nose Most common location of Keisselbach’s plexus Veins from the anterior nasal epistaxis Facial vein cavity Children Adults Pterygoid Veins that pass with branches that - Kiesselbach's Plexus - Woodruff's Plexus plexus ultimately originate from maxillary - Little's Area Page 10 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 artery discharge) Frequent sneezing Superior ophthalmic veins Itchiness of the nose, throat, and drain to the cavernous sinus in eyes Emissary cranial cavity veins Nasal vein in the foramen Rhinoscopy Pale boggy turbinates: cecum Findings Turbinates are edematous, almost obstructing the nasal cavity Veins (normally, turbinates are pink) accompanying Submucous venous plexus Watery nasal discharge arteries Nasal Septal Deviation: Due to frequent manipulation of the nose (e.g. scratching of the nose) 2.4.2. Lymphatic Drainage 2.5. INTERNAL NOSE: NERVOUS SUPPLY Lymph Nodes Structure Drained Submandibular Vestibule NERVOUS SUPPLY OF THE INTERNAL NOSE Upper deep cervical The rest Olfactory n. From the olfactory mucous (CN I) membrane, ascend through the cribriform plate of the ethmoid bone 2.4.3. Clinical Correlates to the olfactory bulb CLINICAL CORRELATES Trigeminal n. Ophthalmic (V1) and Maxillary (V2) (CN V) divisions are nerves of ordinary NASAL VESTIBULITIS sensation Facial n. Autonomic nerve via the (CN VII) pterygopalatine ganglion Parasympathetic - nasal secretion Sympathetic - nasal airflow 3. PARANASAL SINUSES NERVOUS SUPPLY OF THE INTERNAL NOSE Fig. 2.10. Patient with nasal vestibulitis Inflammation of the nasal vestibule Trauma due to digital manipulation or vibrissae pulling Common causative agent: Staphylococcus aureus Infection in the dangerous area of the face can reach the cavernous sinus through the valveless Fig. 3.1. Paranasal Sinuses angular veins of the face and ophthalmic veins Cavities found inside the facial ALLERGIC RHINITIS bones: ○ Maxilla * Disorder of the nose, induced after allergen ○ Frontal exposure by an IgE-mediated inflammation of Characteristics ○ Sphenoid * the nasal mucosa ○ Ethmoid Lined by mucoperiosteum and Symptoms Intermittent nasal congestion are filled with air Watery rhinorrhea (watery nasal (air-containing only) Page 11 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 Communicate with the nasal lead to accumulation of mucus cavity through relatively small within the sinuses apertures or ostium Can cause facial Maxillary and sphenoid pain/headache sinuses Stasis of mucus can lead to ○ Present in a rudimentary bacterial growth/infection form at birth ○ Enlarge appreciably at the 3.1.1. Sinusitis 8th year and becomes fully formed during adolescence CASE 2: SINUSITIS Humidification A medical student sought consultation due to Vocal resonance tenderness over the right cheek of 10 days duration. Mucus production This was accompanied by fever, nasal blockade, and Increased olfactory surface hyposmia. PE showed turbinate congestion with Functions area yellowish mucus nasal discharge. Absorption of shock to the head Regulation of intranasal pressure 3.1. DRAINAGE OPENINGS OF PARANASAL SINUSES ethmoid Bulla A * Hiatus semilunaris ↳ Sphenoethmoidal Recess # Superior meatus Intundibulum # A Fig. 3.3. Presentation of patients with sinusitis Nasal congestion Symptoms Localized facial pain Mucoid to purulent diarrhea Fig. 3.2. Openings of the paranasal sinuses Facial pain / Pain Maxillary between eyes Hiatus Orifice of maxillary sinus Structures Semilunaris Ethmoid involved Headache or Frontal Orifice of posterior ethmoid Superior Meatus cells Sphenoid Pain at vertex of the head Sphenoethmoidal Inflammation of the Paranasal Ostium of sphenoid sinus Recess Sinuses Caused by an obstruction of the Orifice of anterior ethmoid cells sinus drainage / ostium Ethmoid Bulla and middle ethmoid cells ○ Leads to mucus Likely accumulation and stagnation Infundibulum Opening of frontal sinus cause within the sinuses Undrained mucus promotes the When a patient has nasal growth of bacterial infection Clinical congestion, this would lead to ○ Causing facial pain or Significance obstruction of one or more headaches depending on the paranasal sinus—which would location of the affected sinuses Page 12 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 4. LARYNX KEUM PALPABLE LANDMARKS LARYNX Thyroid notch (Adam’s apple) is more prominent Males The thyroid cartilage in males grows faster and bigger during puberty compared to females Females Cricoid cartilage is more prominent To establish the location of the Significance airways 4.1. Laryngeal Landmarks KEUM HYOID BONE THYROHYOID MEMBRANE Fibrous tissue that connects the inferior border of Fig. 4.1. Surface Anatomy of Anterior Neck the hyoid bone to the superior border of the thyroid cartilage Holes on the side are where the superior laryngeal artery and the internal branch of the superior laryngeal nerve enters the larynx THYROID CARTILAGE Superior 2 lateral horns Normal to feel pain One on each side (2) Thyroid Meets at the center to create the Fig. 4.2. Indirect and Flexible Laryngoscopy lamina laryngeal prominence (Adam’s apple) Located in the anterior neck It is situated below the tongue and the hyoid bone 2 lateral ○ Between the great vessels of the neck Inferior Connects to the lateral side of the ○ Lies at the level of the 4th-6th cervical horn posterior arc of the cricoid vertebra cartilage Provides a protective sphincter CRICOTHYROID MEMBRANE at the inlet of the air passages Responsible for voice production Between the inferior border of the thyroid Internal features can be cartilage and the superior border of the anterior Functions visualized through: cricoid cartilage ○ Laryngeal mirror (Indirect Location for establishment of an airway in an laryngoscopy) impending airway obstruction ○ Rigid or flexible laryngoscope (cricothyroidotomy) If Heimlich Maneuver doesn’t work during emergency situations CRICOID CARTILAGE Below the cricoid are your tracheal rings Page 13 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 4.2. Laryngeal Folds KEUM LARYNGEAL FOLDS When the membranes and ligaments are covered with mucosa, this will create folds. If you want to use the word “fold”, it should [pertain to] vestibular vocal fold; if you want to use “cord”, it should [pertain to] true or false vocal cord Vestibular/ Ventricular “False vocal folds” fold Vocal fold “True vocal folds” Fig. 4.3.3 Aditus of larynx 4.3. Internal Structures of the Larynx KEUM Flared upper entrance of the larynx A funnel-shaped area of the INTERNAL STRUCTURES OF THE LARYNX larynx between the two Aditus laryngitis vestibular folds (laryngeal inlet) The internal structure of the larynx and hollow spaces in the upper airway at the level begins at this structure Fig. 4.3.1. Frontal section of the internal structures of the larynx Fig. 4.3.4. Frontal view of rima vestibuli and rima glottidis Fig. 4.3.2 Frontal view of aditus laryngitis or laryngeal Fig. 4.3.5. Axial view of rima vestibuli and rima inlet glottidis Page 14 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 The median gap or space Stratified squamous epithelium Rima vestibuli between the two vestibular / (vestibule) ventricular folds (“false Mucosa or lining covering the (true) vocal folds vocal folds”) (blue box) The narrow median gap or Pseudostratified columnar ciliated epithelium Rima glottidis space between the two vocal (Respiratory epithelium) (glottis) folds (“true vocal folds”) Mucosa or lining from the trachea going up to the aryepiglottic folds With goblet cells 4.3.2. Divisions of the Larynx DIVISIONS OF THE LARYNX Fig. 4.3.6 Frontal view of ventricle and saccule Narrow slit between the vestibular and vocal folds. It is extended into a tiny blind sac termed saccule or sinus The space between the false Ventricle and true vocal folds Fig. 4.5. Division of Larynx ○ Because they have two lateral recesses that ends Tip of the epiglottis → lateral margin blindly into pouches called of the ventricle at its junction with the the laryngeal saccules Supraglottis superior surface of the true vocal fold 4.3.1. Lining Epithelium Involves the superior and inferior surface of the true vocal folds, as LINING EPITHELIUM well as its most anterior extent called the anterior commissure and its posterior extent called the posterior commissure Glottis Begins from the inferior border of supraglottis or the lateral junction of ventricle From there, we measure 10mm and that should be the inferior extent of the glottis Starts from the inferior surface of the glottis (junction of the squamous and Infraglottis/ respiratory epithelium of the true Subglottis vocal folds) → most inferior level or edge of the cricoid cartilage Fig. 4.4. Lining Epithelium Page 15 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 4.4. Indirect LaryngoscopyCPM 4.5. Flexible LaryngoscopyCPM INDIRECT LARYNGOSCOPY FLEXIBLE LARYNGOSCOPY Use of dental mirror to see the reflection of In this procedure, the scope is passed through laryngeal structures transnasally ○ Called “indirect” because the vocal folds are ○ Through the nasal cavity not seen directly but through a reflection Anteriorly located structures of the larynx: reflected on superior part of the mirror PROCEDURE Posteriorly located structures of the larynx: reflected on inferior part of the mirror 1 Following the space parallel to the floor of the nose, we enter the nasal cavity until we reach the posterior choana PROCEDURE 2 Once the nasopharyngeal wall is visible, 1 Gently grasp the tongue and slightly pull it we direct the endoscope inferiorly outward Insert the laryngoscope ○ Avoid touching the soft palate and posterior pharyngeal wall so as not to elicit gag reflex ○ If still elicited use topical anesthesia 2 Angulate the mirror to visualize the vocal folds Fig. 4.7.1. Nasopharyngeal wall 3 Further down, the epiglottis (white structure) will be seen along with the base of the tongue ○ The space between the epiglottis and the tongue is called the vallecula Fig. 4.6.1. Angulation of the mirror 3 Instruct the patient to phonate and then breathe ○ Observe the movement of the white tissue structure (true vocal folds) Fig. 4.7.2 Epiglottis, vallecula, and base of the tongue Fig. 4.6.2. Indirect laryngoscopy with Closed (left) and Opened (right) vocal folds Page 16 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 4 Proceeding downward, we can see the elastic cartilage Epiglottis Arytenoid arytenoid on each side Thyroid cartilage Corniculate Aryepiglottic folds are the folds of tissue Haliea Cricoid cartilage Cuneiform between the arytenoid and the epiglottis Pyriform sinus are spaces behind the 4.6.1. Unpaired Laryngeal Cartilages aryepiglottic folds UNPAIRED LARYNGEAL CARTILAGES Fig. 4.7.3. Arytenoid cartilage 5 True vocal folds False vocal folds are superior to the true vocal folds Ventricle is the space between the true and false vocal folds Fig. 4.8.1. Unpaired cartilages of the larynx THYROID CARTILAGE Fig. 4.7.4. True vocal folds · ( Fig. 4.8.2. Thyroid cartilage Fig. 4.7.5. Abducted (left) and adducted (right) vocal folds LARGEST cartilage of the larynx Consist of two lamina of hyaline cartilages which splits at midline to form prominent V-angle 4.6. CARTILAGINOUS FRAMEWORK (Adam’s apple) CRICOID CARTILAGE 9 LARYNGEAL CARTILAGES 3 UNPAIRED 3 PAIRED Page 17 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 posterior lamina of cricoid cartilage via cricoarytenoid joint 1 Broad Plate Vocal process projects FORWARD; provides Shallow Arch [ attachment to vocal ligament. Muscular process projects LATERALLY; provides attachment to the posterior and lateral cricoarytenoid muscles. CONNICL CORNICULATE CARTILAGES Small, conical shaped Articulates with apices of arytenoid cartilages Provides attachment to the aryepiglottic folds Fig. 4.8.3. Cricoid cartilage CUNEIFORM CARTILAGES Signet ring-shaped Hyaline cartilage Small, rod-shaped Broad plate behind and a shallow arch anteriorly Within aryepiglottic fold ○ Function: strengthens fold EPIGLOTTIS Leaf-shaped lamina of elastic cartilage 4.7. LARYNGEAL LANDMARKS Lies behind root of the tongue Stalk is attached to the back (inner surface) of the thyroid cartilage → via thyroepiglottic ligament LARYNGEAL LANDMARKS Sides are attached to the arytenoid cartilage → via aryepiglottic folds of mucous membrane Upper edge is free, no attachments; inferior edge is fixed Functions as a stopper to protect the glottis 4.6.2. Paired Laryngeal Cartilages PAIRED LARYNGEAL CARTILAGES Fig. 4.10. Laryngeal landmarks LARYNGEAL PROMINENCE Adam’s apple Palpate to identify area of larynx Represents the anterior surface of the thyroid cartilage THYROHYOID MEMBRANE Fig. 4.9. Paired cartilages of the larynx Fibrous tissue that connects inferior border of hyoid ARYTENOID CARTILAGES bone to superior border of the thyroid cartilage Paired, small, pyramidal-shaped THYROID CARTILAGE Located at the back of the larynx Helps strengthen and keep the larynx functioning Superior horns → 2 lateral as a unit Thyroid lamina → one on each side ○ Meets at center → adam’s apple APEX Articulates with corniculate cartilages Inferior horn → 2 lateral ○ Connects to the lateral side of the posterior BASE Articulates with superior border of the Page 18 of 29  D-paired * - Unpaired Leaf # shaped * A D D PyramidalChaped Conical - shallow - broad figret-ring shaped UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 arc of the cricoid cartilage membrane cartilage and thyroid cartilage CRICOTHYROID MEMBRANE The ligament may be pierced for emergency cricothyrotomy Between the inferior border of the thyroid cartilages and superior border of the anterior LARYNGEAL LIGAMENTS cricoid cartilage Location for emergency airway access via Cricotracheal Between the inferior border of the cricothyroidotomy ligament cricoid cartilage and the first tracheal ring 4.8. LARYNGEAL JOINTS CMM Hyoepiglottic In the posterior surface of the hyoid ligament bone; connected to the lingual side of the epiglottis LARYNGEAL JOINTS Thyroepiglottic Connects the epiglottis to the ligament thyroid cartilage INTRINSIC LIGAMENTS Fig. 4.11. Laryngeal joints There are two important joints in the larynx. ⑧ These are two pairs of synovial joints Each joint allows multiaxial movement of rotation E and gliding A connection between the inferior Cricothyroid Fig. 4.12. Intrinsic ligaments of the larynx cornu of the thyroid cartilage and joint the lateral side of cricoid Unites the cartilages of the larynx A space between the base of the Perform important roles in the sphincter or closure Cricoarytenoid arytenoid cartilage and the function of the larynx, as well as phonation or joint superior border of the lamina of sound production of larynx. the cricoid cartilage Vestibular - ligament 4.9. LARYNGEAL MEMBRANES AND LIGAMENTS Framework of the vocal fold, and has a free upper edge LARYNGEAL MEMBRANES AND LIGAMENTS Vocal ligament The free upper edge is the superior extent of the conus Laryngeal membranes bind the cartilages to the elasticus adjoining structures and to one another, and round out the laryngeal framework ELASTIC MEMBRANES LARYNGEAL MEMBRANES Fibrous framework of the larynx and lies beneath the Thyrohyoid A connection between the thyroid mucosa, divided into an upper and lower portions by membrane cartilage and hyoid bone the ventricle Cricothyroid A membrane between the cricoid Quadrangular Upper portion Page 19 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 membrane Attaches anteriorly to the Function to support the true lateral margin of the vocal cords epiglottis epiglottis, wraps around posteriorly to attach to Vocal fold Superior border of the conus the arytenoids and (True vocal elasticus corniculate cartilage cord) Thinner but stronger vocal folds Inferior extent is continuous Composed of the vocal with the vestibular ligament ligaments and the vocalis portion of the thyroarytenoid Also known as the triangular muscle ligament Structures that completely meet Lower portion at the midline to produce a Conus Originates inferiorly along the sound elasticus superior border of the cricoid and inserts into the vocal ligaments and vocal REVIEW QUESTION process of arytenoids The contraction of these muscles causes the lengthening of the true vocal folds and increases the 4.10. LARYNGEAL FOLDS pitch of the voice. A. Cricothyroid muscles LARYNGEAL FOLDS B. Lateral cricoarytenoid muscles C. Posterior cricoarytenoid muscles D. Thyroarytenoid muscles Answer: A & Quadrangla Fig. 4.13. Laryngeal folds Aryepiglottic Superior border of the fold quadrangular membrane Vestibular fold Inferior border of the (False vocal quadrangular membrane cord) Paired higher membranous folds Found on the more lateral portion and do not meet Page 20 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 4.11. EXTRINSIC LARYNGEAL MUSCLES Most are attached to the hyoid bone ○ Important during swallowing ○ Hyoid bone is attached to the thyroid cartilage via the thyrohyoid membrane Movements of the larynx accompany movements of the hyoid bone SUPRAHYOID MUSCLES INFRAHYOID MUSCLES Elevators Depressors Fig. 4.14.1. Suprahyoid muscles Fig. 4.14.2. Infrahyoid muscles Muscles above hyoid bone Muscles below hyoid bone Responsible for the elevation of the hyoid and larynx Responsible for the depression of the larynx during ○ Mylohyoid swallowing ○ Geniohyoid ○ Sternothyroid ○ Digastric DGSM ○ Sternohyoid SOTS ○ Stylohyoid ○ Thyrohyoid ○ Omohyoid 4.12. INTRINSIC LARYNGEAL MUSCLES Responsible for: Includes: ○ Movement of vocal folds (closing, opening, Thyroepiglottic muscle relaxation, and tension) Aryepiglottic muscle ○ Airway protection (caring function of the larynx) Thyroarytenoid muscle ○ Sound production Cricoarytenoid muscle Have both origin and insertion onto laryngeal ○ Lateral cricoarytenoid elements ○ Posterior cricoarytenoid Muscles that move the laryngeal inlet Interarytenoids ○ Aryepiglottic muscle - narrowing ○ Transverse arytenoid muscle ○ Thyroepiglottic muscle - widening ○ Oblique arytenoid muscle Cricothroid muscle ○ Straight part ○ Oblique part Page 21 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 Fig. 4.15. Intrinsic laryngeal muscles INTRINSIC LARYNGEAL MUSCLES UT Control vocal fold movement ADDUCTORS ABDUCTORS TENSORS Lateral Primary adductor Cricoarytenoid of the larynx Transverse and Only oblique Interarytenoid abductor of interarytenoid the larynx Responsible for muscles Posterior Only muscle production of Cricoarytenoid Cricothyroid responsible high-pitched Its contraction for voice relaxes the respiration true vocal Thyroarytenoid folds (TVF) Function during phonation LARYNGEAL ADDUCTOR MUSCLES Muscles responsible for adduction or bringing the vocal folds together and the arytenoid cartilage itself LATERAL CRICOARYTENOID Originates from the lateral cricoid arch to the muscular process of the arytenoid During contraction, it rotates the vocal process of the arytenoid and the vocal ligament medially, causing Fig. 4.16.1. Lateral adduction Fig. 4.16.2. Action of the lateral cricoarytenoid cricoarytenoid Exhalation → narrow aperture; whispering Page 22 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 INTERARYTENOID Connects arytenoids of both sides During contraction, it glides the arytenoids toward the midline Narrows the space or closes the glottis (adduction) Fig. 4.17.2. Action of the interarytenoids Fig. 4.17.1. Interarytenoid Exhalation → brings cords together; phonation THYROARYTENOID Origin is the inner surface of the thyroid cartilage Insertion through the arytenoids Contraction decreases the length of the vocal folds as well as its tension Fig. 4.18.1. Thyroarytenoid Fig. 4.18.2. Action of the thyroarytenoid Exhalation → loosen cords; lower pitch LARYNGEAL ABDUCTOR MUSCLES POSTERIOR CRICOARYTENOID Posterior lamina of O cricoid cartilage Muscular process of I arytenoid Brings muscular process of arytenoid posteriorly Brings vocal A process of Fig. 4.19.1. Posterior arytenoid laterally Fig. 4.19.2. Action of the posterior cricoarytenoid cricoarytenoid Contraction → Widen aperture for inhalation abduction of vocal folds, opening of glottis Page 23 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 LARYNGEAL TENSOR MUSCLES POSTERIOR CRICOARYTENOID Superior border of cricoid cartilage to O inferior border of cricoid cartilage Decreases distance between cricoid and thyroid cartilage A Fig. 4.20.1. Cricothyroid Increases distance Fig. 4.20.2. Action of the cricothyroid between arytenoid Stretch cords, increase pitch and thyroid cartilage 4.13. NEUROVASCULAR SUPPLY REVIEW QUESTION NERVE SUPPLY OF THE LARYNX A patient who underwent total thyroidectomy was observed to have a breathy voice and immobile left true vocal folds post-operatively. Which structure is injured during the surgery? A. Internal Laryngeal Nerve B. Recurrent Laryngeal Nerve C. External Laryngeal Nerve D. Vagus Nerve Answer: B Additional Information: Fig. 4.21. Nerve supply of the larynx The recurrent laryngeal nerve enters the larynx from the inferior part and pierces into the larynx. It provides Innervation of larynx comes from vagus nerve (CNX) motor innervation to all intrinsic laryngeal muscles except cricothyroid. Recurrent Runs in tracheoesophageal laryngeal nerve groove, and enters larynx Injury to the external laryngeal branch of the superior from the inferior part laryngeal nerve, the patient will not be able to do MOTOR: all intrinsic falsetto. laryngeal muscles except cricothyroid SENSORY: mucosa below BLOOD SUPPLY OF THE LARYNX vocal folds Dual blood supply from superior and inferior Superior 2 branches laryngeal artery laryngeal nerve ○ Internal laryngeal n. ○ External laryngeal n. Vagus Nerve External laryngeal MOTOR: cricothyroid nerve Recurrent Laryngeal Superior Laryngeal MOTOR : I I Internal laryngeal SENSORY: all structures · ALL intrinsic muscle external Laryngeal Internal Laryngeal nerve and mucosa above vocal except cricothyroid MOTOR JeNJORY : : folds folds · Cricothyroid · Above vocal Sensory : won't be > Injury : Below Vocal folds able to dofalsetto voice & > Injury : breathy immobile left true vocal cords Page 24 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 LYMPHATIC DRAINAGE OF THE LARYNX Fig. 4.22. Blood supply of the larynx Superior Branch of the superior laryngeal a. thyroid artery from the ECA Fig. 4.24. Lymphatic drainage of the larynx Inferior laryngeal Branch of the inferior a. thyroid artery from the Superior deep thyrocervical trunk cervical lymph Above level of vocal folds nodes VENOUS DRAINAGE OF THE LARYNX Inferior deep Below the level of vocal cervical lymph folds Parallels arterial supply nodes 4.13.1. Vocal Fold Mass CLINICAL ANATOMY: VOCAL FOLD MASS Fig. 4.23. Venous drainage of the larynx Superior Drains via IJV laryngeal v. Main drainage Fig. 4.25. Image of vocal fold mass Inferior laryngeal Via subclavian/ Change in the quality of voice (cannot phonate v. brachiocephalic vein properly) Mass along the true vocal folds causes hoarseness or dysphonia ○ Prominent voice quality is rough due to irregularity in the vibration of the vocal folds during phonation Lesions may be malignant, benign, infectious, and inflammatory Page 25 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 Some lesions may enlarge and obstruct the airway and present as stridor 4.13.2. Laryngeal Edema CLINICAL ANATOMY: LARYNGEAL EDEMA Fig. 4.27. Vocal fold paralysis (Powerpoint slide of Dr. Lingan) Structure Vocal folds affected Structures Recurrent laryngeal nerve on each injured during side procedure BILATERAL VOCAL FOLD PARALYSIS Fig. 4.26. Diffuse laryngeal edema of the larynx. Causes Congenital (Powerpoint slide of Dr. Lingan) Iatrogenic Diffuse laryngeal edema of the larynx is an airway Clinical Stridor emergency. Presentation Dyspnea Often managed with tracheostomy to reestablish Signs of Respiratory Distress the airway. ○ Cricothyroidotomy: may also be performed to During breathing, the vocal folds are not establish airway abducting/separating. What can only be seen is the vibration of the vocal folds and the passage of the air through the vocal folds. Causes Anaphylactic Reaction Post-radiotherapy Lymphatic Obstruction CASE 4 Clinical Stridor (Noisy Breathing) An elderly woman was referred due to hoarseness, Presentation Dyspnea with coughing especially after drinking water. She is Airway Obstruction undergoing treatment for pulmonary TB with multiple mediastinal lymphadenopathy. Indirect laryngoscopy showed immobile left vocal folds. 4.13.3. Vocal Fold Paralysis CASE 3: VOCAL FOLD PARALYSIS Upon emergence from anesthesia after total thyroidectomy, the patient was noted to have stridor and difficulty breathing. She subsequently underwent a tracheostomy. Fig. 4.28. Vocal fold paralysis (Powerpoint slide of Dr. Lingan) Page 26 of 29 UPPER RESPIRATORY TRACT GROSS AND CLINICAL ANATOMY LESSON #7 Structure Left true vocal folds affected What caused Compression of recurrent laryngeal immobility of nerve on the left side vocal fold? UNILATERAL VOCAL FOLD PARALYSIS Causes Idiopathic The image shows a soft tissue lateral view of the Iatrogenic face. There is a dislocated displaced fracture of the nasal Clinical Breathy Voice Quality bone. Presentation Voice Fatigue ○ Normally, it should be continuous; but the patient Aspiration During Feeding has disalignment, indicating the nasal bone fracture. The recurrent laryngeal nerve takes a longer course 2. The eustachian tube is located near which of the in the mediastinum. So it is usually affected by lesions following areas? within the mediastinum. a. Nasal vestibule b. Atrium SUMMARY c. Middle meatus d. Posterior choana Eustachian Tube visible near the posterior choanae. Openings Ear side: middle ear Nasal side: Posterior choanae Function middle ear ventilation and pressure equalization