Anatomy of the Larynx PDF - Overview & Diagrams

ANATOMY OF THE LARYNX 1  OUTLINE Introduction Developmental Anatomy Framework Lining Membrane Neurovasculature Conclusion 2  INTRODUCTION The larynx is the upper end of the lower respiratory tract...

ANATOMY OF THE LARYNX 1  OUTLINE Introduction Developmental Anatomy Framework Lining Membrane Neurovasculature Conclusion 2  INTRODUCTION The larynx is the upper end of the lower respiratory tract Protective sphincter; regulates passage of air; organ of phonation Forms the anterior prominence of the neck commonly called the Adams apple  INTRODUCTION Lie in anterior midline of neck From root of tongue to trachea From laryngeal inlet up to lower border of cricoid cartilage C3-C6 vertebrae in men Supraglottis, glottis and subglottis 4 RELATIONS  DIMENSION Males Females Length 44 mm 36mm Transverse 43 mm 41 mm diameter 36 mm 26 mm A-P diameter 136mm 112 mm Circumference EMBROLOGY OF LARYNX 7 EMBROLOGY OF LARYNX 8 EMBROLOGY OF LARYNX 9  COMPOSITION Larynx is made up of the Cartilages that are connected by: Ligaments and membranes, lined by Mucus membranes and moved by Muscles  FRAMEWORK 3 UNPAIRED 3 PAIRED CARTILAGES CARTILAGES Thyroid Arytenoids Cricoid Corniculate Epiglottis Cunieform … and hyoid bone Ossification THYROID CARTILAGE 12 CRICOID CARTILAGE  EPIGLOTTIS Thin lamella of fibrocartilage that rises behind the tongue It is leaf –like shaped  ARYTENOIDS Pyramidal shaped Base is concave. Articulates with the cricoid cartilage Apex curves backwards to articulate with the corniculate cartilage. CORNICULATE (SANTORINI) Corniculate extends the apex of the arytenoids Provides structural rigidity to aryepiglottic fold  CUNEIFORM (WRISBERG) Cuneiform cartilage are small bars of yellow elastic cartilages on each aryepiglottic fold HYOID BONE 18 JOINTS OF THE LARYNX  LIGAMENTS AND MEMBRANES OF THE LARYNX Extrinsic Intrinsic  EXTRINSIC Thyrohyoid membrane Median thyrohyoid ligament Lateral thyrohyoid ligament Cricotrachael membrane Hyoepiglottic ligament  INTRINSIC Fibroelastic membrane of the larynx lies beneath the laryngeal mucosa Upper part supports the aryepiglottic and ventricular folds Lower part forms the Conus elasticus  Muscles of the Larynx -Extrinsic Primary elevators: stylopharyngeus, salpingopharyngeus , palatopharyngeus, thyrohyoid Secondary elevators: mylohyoid, stylohyoid, geniohyoid, digastric  Muscles of the Larynx -Extrinsic Depressors: sternohyoid, sternothyroid, omohyoid MUSCLES OF THE LARYNX -INTRINSIC Abductors of vocal cord  Posterior cricoarytenoid muscle Adductors of vocal cord  Lateral cricoarytenoids  Transverse arytenoids  Oblique thyroarytenoids MUSCLES OF THE LARYNX -INTRINSIC Tensors of focal cord  Cricothyroid muscle  Vocalis Alter shape of laryngeal inlet  Thyroepiglotticus  Aryepiglotticus CAVITY OF THE LARYNX Vestibule : Inlet and Vestubu edge of false fold lar fold Ventricle: between false and true folds Anterior  Saccule commiss Infra-glottic: ure between true cord Vocal and lower border of fold cricoid cartilage  SPACES OF THE LARYNX Preepiglottic space Paraglottic space 28  THE GLOTTIS The glottis lies between apex of the laryngeal ventricle and a line drawn 1 cm below the medial free edge of the vocal fold. Rima glottidis: 24 mm in men and 16 mm in women  LINING MEMBRANE Ciliated pseudostratified columnar epithelium; loosely attached Non-keratinizing stratified squamous epithelium  Laryngeal inlet  Vocal fold Mucous glands  Numerous in posterior surface of epiglottis, saccule  Absent in vocal fold  FOCAL FOLD Membraneous and cartilaginous parts Epithelial layer Lamina propria  Superficial layer (Reinke’s space)  Intermediate layer  Deep layer Vocalis muscle Broyle’s ligament and anterior macula flava 31 LARYNGOSCOPIC VIEW Inspiration Phonation  NERVE SUPPLY Superior laryngeal nerve  Internal branch  External branch Recurrent laryngeal nerve  BLOOD SUPPLY Superior laryngeal artery Inferior laryngeal artery Cricothyroid artery  BLOOD SUPPLY Superior laryngeal vein Inferior laryngeal vein Tributaries of middle thyroid vein LYMPHATIC DRAINAGE 36  FUNCTIONS OF LARYNX Protection of lower airways Respiration Phonation Fixation of the chest 37  PAEDIATRIC LARYNX Position: high in the neck with level of glottis being opposite to C3 or C4 Small and conical Soft cartilages Flat thyroid cartilage Comparatively loose submucosa 38  CONCLUSION The larynx is an essential organ with complex functions Mobile, coordinated and sensate Knowledge of anatomy is key to understanding pathophysiology of related diseases Age related changes and differences are of clinicopathologic and surgical importance 39 THANK YOU FOR LISTENING 40