Larynx Part 1 PDF

The University of Jordan Faculty Of Medicine Anatomy of the Larynx DR. AHMED SALMAN Associate professor of anatomy & embryology DR.AHMED SALMAN The Larynx The larynx is composed of : Ø Cartilage Ø Muscles Ø Joints Ø Membranes DR.AHMED SALMAN Cartilage Single cartilages Epiglottis Thyroid cart...

The University of Jordan Faculty Of Medicine Anatomy of the Larynx DR. AHMED SALMAN Associate professor of anatomy & embryology DR.AHMED SALMAN The Larynx The larynx is composed of : Ø Cartilage Ø Muscles Ø Joints Ø Membranes DR.AHMED SALMAN Cartilage Single cartilages Epiglottis Thyroid cartilage. Cricoid cartilage Paired cartilages 2 arytenoids 2 corniculates. 2 cuneiforms Functions of the Laryngeal Cartilages : -They prevent collapse of the air passages and give attachment to a series of muscles. DR.AHMED SALMAN 1-Thyroid Cartilage q The posterior vertical border has superior and inferior horns (cornua) q It receives the insertion of three muscles :stylopharyngeus, salpingopharyngeus and palatopharyngues. q The lateral surface of each lamina presents an oblique line . q The oblique line provides attachment for three muscles: sternothyroid, thyrohyoid and thyropharyngeus part of the inferior pharyngeal constrictor DR.AHMED SALMAN Superior horn of thyroid cartilage Inferior horn of thyroid cartilage Thyroid cartilage DR.AHMED SALMAN 2-The Cricoid Cartilage : -It has the shape of a signet ring -At the junction of the arch with the lamina, there is an articular facet (on each side) for the cricothyroid joint . lamina Arch DR.AHMED SALMAN 3-The Epiglottis : - It is a leaf-like sheet of elastic fibrocartilage which projects upwards behind the tongue and hyoid bone. -It has 2 ends, 2 surfaces and 2 sides. The superior end : broad and free The inferior end : narrow, attached to the thyroid cartilage by the Thyroepigloltic ligament Anterior surface : its is connected to the back of the tongue by the median and the right and left glosso-epiglottic folds with the two valleculae in between. Posterior surface : is concave and smooth Sides of the epiglottis : from each side, the aryepiglottic fold passes to the arytenoid cartilage. DR.AHMED SALMAN Epiglottis Thyro-epigloltic ligament DR.AHMED SALMAN Valleculae median glosso-epiglottic fold Two lateral glosso-epiglottic folds DR.AHMED SALMAN DR.AHMED SALMAN Aryepiglottic fold DR.AHMED SALMAN DR.AHMED SALMAN valleculae DR.AHMED SALMAN (4)Two Arytenoid Cartilages : -They are placed on the upper border of the cricoid lamina. -Each is a pyramid, has an apex, base, 3 surfaces The apex : articulates with the comiculate cartilage. The base : articulates with the upper border of the cricoid lamina (cricoarytenoid joint). Two processes: muscular process (directed laterally) and vocal process (directed anteriorly). DR.AHMED SALMAN Arytenoid Cartilages DR.AHMED SALMAN Muscular process of arytenoid cartilage DR.AHMED SALMAN Vocal process of arytenoid cartilage arytenoids Cricoid cartilage DR.AHMED SALMAN (5) Corniculate and (6) Cuneiform Cartilages : - Are small nodules in the posterior part of the ary-epiglottic fold. DR.AHMED SALMAN Joints of the larynx 1. Cricothyroid Joint : Type: Synovial joint Articulation : the thyroid cartilage and the facet on the side of the cricoid cartilage. 2. The Crico-arytenoid Joints : Type: Synovial joint Articulation : upper border of the cricoid lamina and the bases of the arytenoid cartilages DR.AHMED SALMAN The Crico-arytenoid Joints Cricothyroid Joint DR.AHMED SALMAN Ligaments and Membranes of the Larynx : A. Extrinsic Group : (1) Thyrohyoid Membrane : -It extends from the hyoid bone to the upper border of the thyroid cartilage. -Its middle part is thickened to form the median thyrohyoid ligament. -Its lateral part (on each side) is thin and pierced by the internal laryngeal N. and superior laryngeal vessels. -Its posterior border (on each side) is thickened to form the lateral thyrohyoid ligament. (2) Crico-tracheal Ligament : Extends between the lower border of the cricoid cartilage and the first tracheal ring. DR.AHMED SALMAN Median thyrohyoid ligament Opening of thyrohyoid membrane Thyrohyoid Membrane DR.AHMED SALMAN DR.AHMED SALMAN Crico-tracheal Ligament DR.AHMED SALMAN B. Intrinsic Group : (1) The Two Quadrangular Membranes :-Each is a fibroelastic membrane which lies beneath the mucous membrane of the vestibule of the larynx. -It has 4 borders (2 attached and 2 free) : Anterior border : is attached to the side of the epiglottis Posterior border : is attached to the arytenoid cartilage. Upper border : is free and forms aryepiglottic fold at the laryngeal inlet. Lower border : is free and forms the vestibular ligament. DR.AHMED SALMAN DR.AHMED SALMAN (2) The Cricothyroid Ligament (Conus Elasticus) : -It is a single fibroelastic membrane which lies beneath the mucous membrane of the lower part of the larynx. -It has an anterior median part and two lateral parts The anterior median part : Is thick and forms the median cricothyroid ligament which connects the adjacent margins of the cricoid and thyroid cartilages. The lateral part : It has an upper free border which forms the vocal ligament. It extends from the angle of the thyroid cartilage (anteriorly) to the vocal process of the arytenoid cartilage (posteriorly). DR.AHMED SALMAN Aryepiglottic fold Cricothyroid Ligament DR.AHMED SALMAN DR.AHMED SALMAN DR.AHMED SALMAN DR.AHMED SALMAN Interior of the Larynx : Shows the following features from above downwards : 1- Inlet of the larynx : Boundaries Anteriorly : epiglottis. Posteriorly : the mucous membrane that stretches between the two arytenoids. On either side : the ary-epiglottic fold containing the corniculate and cuneiform cartilages. Lateral to ary-epiglottic fold , there is the piriform fossa of laryngeopharynx. DR.AHMED SALMAN 2-Vestibule : Lies between the laryngeal inlet and the vestibular folds. 3-Vestibular folds : They are called the false cords v The fissure between the two vestibular folds is called rima vestibuli. 4. Ventricle and saccule of larynx : The ventricle is the narrow groove between the vestibular and vocal folds. The saccule is a small pouch of mucosa for lubrication of the vocal cords . DR.AHMED SALMAN 5. The vocal folds : -Each is a fold of mucosa containing the vocal ligament. Special features a. It is avascular, so appears as a shining white cord in the living. b. Its ligament is rich in elastic fibers. c. It has no lymphatics. Rima glottis : it is the fissure which lies between the vocal folds and medial surfaces of the bases of the arytenoid cartilages. It has the following features: a. It is the narrowest part of the larynx b. its anterior 3/5 is called the intermembranous part (between the vocal folds) and posterior the vocal ligament c. its shape varies with the movements of the vocal folds. DR.AHMED SALMAN 6. The infraglottic part of the larynx : Extends from below the vocal folds down to the lower bolder of the cricoid cartilage. DR.AHMED SALMAN DR.AHMED SALMAN DR.AHMED SALMAN The Piriform Fossa : Is a small recess on either side of laryngeal inlet Boundaries : Medially : Aryepiglottic fold Laterally : Thyroid cartilage and thyrohyoid membrane. Beneath the mucous membrane of the fossa the branches of the internal laryngeal N. are passing It is common site of foreign body location DR.AHMED SALMAN DR.AHMED SALMAN DR.AHMED SALMAN DR.AHMED SALMAN DR.AHMED SALMAN