Larynx Anatomy PDF

 Larynx Extension Opposite C4,5,6 Cartilages o Single cartilage:  Epiglottis: Leaf-like cartilage which lies behind tongue & hyoid bone  Thyroid cartilage: Formed of 2 laminae fused at midline at “...

 Larynx Extension Opposite C4,5,6 Cartilages o Single cartilage:  Epiglottis: Leaf-like cartilage which lies behind tongue & hyoid bone  Thyroid cartilage: Formed of 2 laminae fused at midline at “Adam apple”  Cricoid cartilage: ring-shaped with narrow anterior arch o Paired cartilage:  Arytenoid cartilage: Pyramidal-shaped with muscular & vocal processes  Corniculate cartilage: found at ary-epiglottic folds  Cuneiform cartilage found at ary-epiglottic folds Membranes o Crico-tracheal ligament o Cricothyroid ligament: Thickened at its upper border forming Vocal cords o Quadrangular ligament:  Thickened at its upper border forming Aryepiglottic fold  Thickened at its lower border forming Vestibular fold o Thyrohyoid membrane: Pierced by internal laryngeal nerve & superior laryngeal artery o Hyo-epiglottic ligament Anatomist “Larynx”  Laryngeal inlet o Boundaries:  Anterior: epiglottis  Lateral: aryepiglottic fold  Posterior: arytenoid cartilage o Clinical importance: Piriform fossa “space on the sides of the inlet” is common site for foreign body lodgment Laryngeal cavity o Supra-glottic part “Vestibule”: Laryngeal inlet &Vestibular folds o Glottic part "ventricle":  Rima vestibuli: between 2 Vestibular folds  Sinus : between vestibular & Vocal folds  Saccule: Lateral extension of sinus  Rima glottidis: between 2 vocal folds o Infra-glottic: between vocal folds & Lower border of cricoid Anatomist “Larynx”  Nerve supply Motor: All muscles of larynx supplied by recurrent laryngeal Except crico-thyroid muscle by external laryngeal nerve. Sensory:  Above vocal fold: supplied by internal laryngeal nerve.  Below vocal fold: supplied by recurrent laryngeal nerve. N.B: unilateral lesion of recurrent laryngeal nerve causes horsness of voice N.B: bilateral lesion of recurrent laryngeal nerve causes suffucation and need for tracheostomy Arterial supply  Above vocal fold: supplied by superior laryngeal of superior thyroid artery.  Below vocal fold: supplied by inferior laryngeal of inferior thyroid artery. Lymph drainage  Above vocal fold: drains into upper deep cervical lymph nodes  Below vocal fold: drains into lower deep cervical lymph nodes Anatomist “Larynx”  Muscles of larynx Muscles control the inlet: 1. Open the inlet: thyro-epiglottic muscle 2. Close the inlet: ary-epiglottic muscle Muscles control vocal cord : 3. Abduct vocal cord: posterior crico-arytenoid muscle 4. Adduct vocal cord: 4a. lateral crico-arytenoid muscle 4b.transverse arytonid muscle Muscles control the voice tone : 5. Tense the vocal cord: Cricothyroid muscle 6. Lax the vocal cord: Thyro-artenoid & vocalis muscles Anatomist “Larynx”  Trachea Length: 10 - 11 cm Beginning: Continuation of larynx at lower border of C6 (opposite lower border of cricoid cartilage). Termination “Carina”: At sternal angle level “disc between T4 & T5” by dividing into right & left bronchi. Arterial supply Inferior thyroid artery supply upper part & bronchial arteries supply lower part Venos drainage left brachiocephalic vein Lymph drainage Pre-tracheal & para-tracheal & deep cervical lymph nodes Nerve supply Sympathetic "middle cervical sympathetic ganglion" Parasympathetic " recurrent laryngeal nerve " Relation it lies between arch of aorta "anteriorly" & esophagus "posteriorly" Bronchi Right bronchus Left bronchus Length Shorter Longer Width Wider Narrower Axis In line with trachea Make angle with trachea Foreign body lodgment More common Less common Division Before entering hilum of the lung After entering hilum of the lung Enter hilum at T5 T6 Anatomist “Larynx”