18Cartilage HistologyElastic: Epiglottis, corniculate, cuneiform & apex of arytenoid. Little or no calcification.Hyaline: Thyroid, cricoid & remaining arytenoid. Calcify as age advances. Ossification begins by yr & is completed by 60 yr.
22Pediatric Larynx Conical in shape & subglottis is narrowest part Positioned high (C3-C4)Moves higher during swallowing allowing simultaneous breathing & feedingLoose sub-mucosal tissues (swell up easily)Soft cartilages that collapse easily
23Membranes & Ligaments Extrinsic: connect thyroid cartilage & epiglottis with hyoid bone; cricoid cartilage with trachea.Intrinsic:connect cartilages of larynx to each other.
52Mucous Membrane Stratified squamous epithelium: Epiglottis (anterior surface + upper half of posterior surface), upper part of aryepiglottic folds & vocal cordsPseudo-stratified ciliated columnar (respiratory) epithelium:Rest of laryngeal mucous membrane
53Nerve Supply Superior Laryngeal Nerve: Internal: sensation to supraglottis & glottisExternal: motor to cricothyroid muscleRecurrent Laryngeal Nerve:sensation to subglottismotor to all intrinsic muscles but cricothyroid
55Lymphatic DrainageSupraglottis: via thyrohyoid membrane into upper deep cervical nodes & thyroid glandSubglottis: via cricothyroid membrane into pretracheal + lower deep cervical nodesGlottis: has no lymphatics
56Functions of Larynx 1. Protection of lower airway 2. Phonation (voice production)3. Passage of air into lungs for respiration4. Chest fixation by glottic closure
57Protection of lower airway a. 3-level below-upward closure of: vocal cords ventricular bands aryepiglottic foldsb. Cessation of respiration: mediated by glossopharyngeal nv & deglutition centre.c. Cough reflex
58Voice Production 1. Voice activating air reservoir in lungs: affects voice intensity2. Voice generation: affects voice pitch3. Voice resonation: affects voice quality4. Voice articulation: affects voice quality
60Neuro-chronaxic theory (?) Vibration of vocal fold muscles due to impulses generated from recurrent laryngeal nerves. Speed is regulated by acoustic center in brain.Obsolete theory because:muscle contraction not so fast to produce vibrationseven paralyzed vocal folds can produce phonationpassive phonation occurs in excised larynges
61Combined Aerodynamic & Myoelastic theory Proposed by Jan Willem van den Berg in 1958Vocal cords kept approximated Subglottic blast of air opens vocal cords from below upwards & causes their passive vibration, producing sound Muscle tension + Bernoulli's effect closes vocal cords below upwards Cycle repeated
65Voice generation High pitch = short, thin, tense, less elastic vocal cords Low pitch = long, bulky, relaxed, more Falsetto voice = tense vocal cords, only edge of vocal fold vibrates & body is relaxed,with small phonatory gap
70Glottis state in phonation Voiceless (full air stream)Breathy voice (murmur)Slack voiceModal voice: maximum vibration, sweet spotStiff voiceCreaky voice (restricted air stream)Glottalized (blocked air stream)
74Guinness World records Georgia Brown (2006):Highest vocal range from G2 to G10Highest vocal note (G10)Adam Lopez (2002):Highest vocal note for male (C8)Tim Storms (2002):lowest vocal note (8 Hz = two octaves below lowest B on a piano)
79Places of articulation Bilabial: both lips Labio-Dental: lips + teeth Dental: teeth + tip of tongue Alveolar: alveolus + tip of tongue Palatal: hard palate + tongue blade Retroflex: tongue tip + hard palate Velar: tongue base + soft palate Glottal: produced in glottis