Anatomy of Larynx PDF

# Anatomy of Larynx ## A.D./ Amal Abdal-Satar - Consultant in Obstetrics and Gynecology, Endoscopy, Infertility and Embryo Transfer - Assistant Professor in Human Anatomy and Embryology, Faculty of Medicine, Tanta University - Executive Director of Tanta University’s Main Center for Community Se...

# Anatomy of Larynx ## A.D./ Amal Abdal-Satar - Consultant in Obstetrics and Gynecology, Endoscopy, Infertility and Embryo Transfer - Assistant Professor in Human Anatomy and Embryology, Faculty of Medicine, Tanta University - Executive Director of Tanta University’s Main Center for Community Services - Director of Human Rights Unit, Tanta University - Member of Gharbia Physicians Syndicate ## Anatomy of Larynx - It is a specialized structure responsible for voice production. - It extends from - **Above**: the inlet of the larynx - **Below**: Beginning of the trachea at 6th cervical vertebrae. - It lies opposite to the 3rd, 4th, and 6th cervical vertebrae. ## Cartilage of Larynx (Skeleton of Larynx) - **Epiglottis** with mucosa - **Hyoid** (H) - **Thyrohyoid membrane** (THM) - **Thyroid cartilage** (T) - **Median cricothyroid ligament** - **Cricothyroid muscle** - **Laryngeal prominence** - **Cricoid cartilage** (C) - **Epiglottis cartilage** - **Superior horn** - **Oblique line** - **Vocal ligament** - **Inferior horn** - **First tracheal ring** - **Corniculate cartilage** - **Arytenoid cartilage**: - Muscular process - Vocal process - **Anterior view** - **Lateral view** - **Midsagittal view** ## Thyroid Cartilage - Consists of 2 laminae of hyaline cartilage which meet in the midline at Adam's apple. - The outer surface of each thyroid lamina has an oblique line for the attachment of muscles. ## Cricoid Cartilage - It is a signet shaped ring of hyaline cartilage. - It has a broad lamina behind and narrow arch in front. - It lies between the thyroid cartilage above and the trachea below. ## Cartilage of Larynx Diagram - A diagram of the anterior and posterior views of the larynx with the following components labeled: - Epiglottis - Thyroid - Cricoid - Hyoid bone - Cuniform - Corniculate - Arytenoid ## Muscles of Larynx Diagram - A diagram of the posterior view of the larynx with the following components labeled: - Arytenoid cartilage, vocal process - Vocalis - Conus Elasticus - Lateral crico-arytenoid - Middle crico-arytenoid ligament - Arytenoid cartilage, muscular process - Posterior cricoarytenoid - Articular facet for thyroid ## View Anterior of the Larynx Diagram - A diagram of the larynx with the following components labeled: - Cricothyroid ligament - Sternohyoid muscle - Cricotracheal ligament - Trachea - Thyroid cartilage - Sternohyoid muscle - Cricoid cartilage ## Membranes and Ligaments of Larynx ### Extrinsic Membrane and Ligaments - **Thyrohyoid membrane** - It is pierced by the superior laryngeal vessels and internal laryngeal nerve. - **Cricotracheal ligament** - Connects the lower margin of the cricoid to the 1st ring of the trachea. - **Hyoepiglottic ligament** - Attaches the epiglottis to the hyoid bone. - **Thyroepiglottic ligament** - Attaches the epiglottis to thyroid cartilage ## Membranes and Ligaments of Larynx Diagram - A diagram of the larynx emphasizing the following components: - Median thyrohyoid ligament - Thyrohyoid membrane - Lateral thyrohyoid ligament - Internal laryngeal nerve - Superior laryngeal artery - Median cricothryoid ligament - Cricothyroid ligament - Cricotracheal ligament ## Membranes and Ligaments of Larynx II - **Hyoid bone** - **Aperture for superior laryngeal vessels and interval laryngeal nerve** - **Aryepiglottic fold** - **Cuneiform cartilage** - **Corniculate cartilage** - **Vestibular ligament** - **Epiglottis** - **Hyoepiglottic ligament** - **Thyrohyoid membrane** - **Quadrangular membrane** - **Thyroepiglottic ligament** - **Thyroid cartilage** - **Vocal ligament** - **Sinus of glottis** - **Cricothyroid membrane** - **Median cricothyroid ligament** - **Cricotracheal ligament** - **Trachea** ## Intrinsic Membrane and Ligaments - They are present under the mucous membrane of larynx - **Quadrangular membrane** - Its lower margin forms the vestibular ligaments which forms the vestibular folds. - **Cricothyroid ligament (Cricovocal membrane)**- Its free upper margin is thickened to form the vocal ligament (vocal cords). - **The vocal cords extend from:** - **Posteriorly**: The vocal process of the arytenoid cartilage. - **Anteriorly**: The middle of the deep surface of thyroid cartilage. ## Inlet of The Larynx - Looks backward and upward into the laryngeal part of the pharynx. - **It is bounded by:** - **Anteriorly**: by the upper margin of the epiglottis - **Laterally**: by the aryepiglottic fold - **Posteriorly**: by the mucous membrane stretched between the 2 arytenoids ## Laryngeal Inlet Diagram - A diagram of the laryngeal inlet highlighting the following components: - Laryngeal inlet = aditus - Anterior: epiglottis - Lateral: aryepiglottic folds - Posterior (and inferior): interarytenoid fold ## Cavity of the Larynx - **Above:** the inlet of the larynx - **Below:** the lower border of the cricoid cartilage. - It is covered with a mucous membrane and has 2 pairs of folds projecting from its lateral walls. - **The upper pair of folds is the vestibular folds** and the fissure between them is the rima vestibuli - **The lower pair of folds is the vocal folds** and the fissure between them is the rima glottis ## Cavity of the Larynx Diagram - A diagram of the cavity of the larynx label the following components: - Vocal fold - Vestibular fold - Aryepiglottic fold - Cuneiform tubercle - Corniculate tubercle - Rima vestibuli - Rima glottidis - Interarytenoid fold ## The Cavity of the Larynx - **Is divided into 3 regions:** - **Vestibule** - It is the part between the inlet and the vestibular fold - **Sinus of larynx** - A small recess on each side of the larynx situated between the vestibular and vocal folds - A diverticulum ascends from the sinus anteriorly between the vestibular folds and the inner surface of thyroid cartilage forming the saccule of larynx. - **Lower part** - Extends between the vocal folds above and the lower border of the cricoid cartilage below ## Sagittal Section of the Larynx Diagram - A diagram highlighting the different parts of the larynx in a sagittal section: - Epiglottis - Aryepiglottic fold - True vocal cords - False vocal cords - Thyroid cartilage - Ventricle/Sinus of larynx - Arytenoid cartilage - Cricoid cartilage - Tongue - Supraglottic part - Infraglottic part ## Sagittal Section of the Larynx Diagram - A diagram showing the sagittal section of the larynx, showing the different parts - Hyoid Bone - Thyrohyoid Membrane - False Vocal Cords - True Vocal Cords - Thyroid Cartilage - Rima vestibuli - Saccule - Vocalis Muscle - Cricoid Cartilage - Rima glottidis - Trachea ## Muscles of the Larynx: 8 - **Crico-thyroid** - Action: Produces tension of the vocal cords - **Posterior crico-arytenoid** - Action: Abducts the vocal cords by rotating the arytenoid laterally; it is life saving. - **Lateral crico-arytenoid** - **Transverse arytenoid** - **Oblique arytenoid** - **Aryepiglotticus** - **Thyro-arytenoid** - **Thyro-epiglottic** ## Muscles of the Larynx Diagram - A diagram of the posterior view of the larynx labeled with the following muscles: - Transverse arytenoid muscle - Thyroarytenoid muscle - Posterior cricoaytenoid muscle - Lateral cricoarytenoid muscle ## Muscles of the Larynx Diagram - A diagram illustrating: - Oblique arytenoid muscle - Transverse arytenoid muscle - Posterior cricoarytenoid muscle ## Muscles of the Larynx Diagram - A diagram of a posterior view of the larynx labeled with the following structures: - Aryepiglottic fold - Aryepiglottic prolongation - Transverse arytenoid muscle - Oblique arytenoid muscle - Posterior cricoarytenoid muscle - Lateral cricoarytenoid muscle - Epiglottis - Thyroepiglottic muscle - Thyroarytenoid muscle - Conus elasticus - Cricothyroid muscle (cut away) ## Blood Supply of the Larynx - **Superior thyroid artery** - Its superior laryngeal branch enters the larynx with the internal laryngeal nerve through the thyrohyoid membrane. - **Inferior thyroid artery** - Its inferior laryngeal branch enters the larynx with the recurrent laryngeal nerve by ascending deep to the lower margin of the inferior constrictor. ## Blood Supply of the Larynx Diagram - A diagram of the blood supply to the larynx emphasizing: - Superior laryngeal artery - Inferior thyroid artery - Internal carotid - External carotid - Superior thyroid - Common carotid - Thyrocervical trunk - Cricothyroideus muscle - Inferior laryngeal - Subclavian ## Blood Supply of the Larynx Diagram - A diagram of the blood supply to the larynx emphasizing: - Superior laryngeal nerve - Internal branch of superior laryngeal nerve - External branch of superior laryngeal nerve - Superior laryngeal artery - Recurrent laryngeal nerve - Inferior thyroid artery ## Lymphatic Drainage of Larynx - **Above the level of vocal cords** - Drains to the upper deep cervical lymph nodes. - **Below the level of vocal cords** - Drains to the prelaryngeal, pretracheal and lower deep cervical lymph nodes. ## Lymphatic Drainage Diagram - A diagram of the lymphatic system of the larynx emphasizing: - Above level of vocal cords - parallel superior laryngeal vessels - Lymph to superior deep cervical nodes - Below level of vocal cords - parallel inferior laryngeal vessels - Lymph to pre-or paratracheal nodes - Then to inferior deep cervical nodes ## Nerve Supply of Larynx ### Motor - ALL the intrinsic muscles of the larynx are supplied by the recurrent laryngeal nerve EXCEPT the cricothyroid which is supplied by the external laryngeal nerve. ### Sensory - **Above the level of the vocal folds:** It is supplied by the internal laryngeal nerve; a branch of the superior laryngeal of vagus. - **Below the level of the vocal folds:** It is supplied by the recurrent laryngeal nerve; a branch from the vagus. ## Laryngeal Nerves Diagram - A diagram highlighting: - Superior laryngeal nerve - Internal laryngeal nerve - External laryngeal nerve - Recurrent laryngeal nerve ## Thank You! This document describes the anatomy of the larynx. It includes descriptions and diagrams of the larynx's cartilage, ligaments, membranes, muscles, blood supply, lymphatic drainage and nerve supply.