Anatomy and physiology of larynx Revy.pptx

Anatomy and physiology of larynx

1. ANATOMY AND PHYSIOLOGY OF LARYNX Literature Reading Revy Octarian Palmendha Supervisor : Dr. dr. Agung Dinasti Permana , Sp.T . H . T . K . L (K) Department of Otorhinolaryngology-Head & Neck Surgery Faculty of Medicine Padjadjaran University Hasan Sadikin General Hospital Bandung 20 20 1

2. Introduction 2 The respiratory system can be divided structurally into : Upper division Lower divisions functionally into : Conducting division Respiratory division Dhingra. Diseases of Ear, Nose and Throat & Head and Neck Surgery 7ed. India: Elsevier India; 2017.

3. Introduction The upper airway includes : N asal Cavity Oral cavity P harynx L arynx 3 Probst R, Grevers G, Iro H. Basic Otorhinolaryngology: A Step-by-Step Learning Guide. second ed. New York: Thieme Publishers; 2017.

4. Introduction 4 Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

5. Framework 5 Bone: - Hyoid Cartilages: Thyroid Cricoid Arytenoids Epiglottis Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

6. 6 Hyoid  supports the larynx and stabilizes the hypopharynx U shaped, two greater horn Two lesser horn Hyoid connected to the thyroid cartilage  the broad thyrohyoid membrane. Hyoid Bone Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

7. 7 Thyroid Cartilage – Greek Name meaning ‘ Shield like ’ T hyroid cartilage : Superior horn  thyrohyoid ligament Inferior horn  cricoid cartilage T o gradually ossify after the age of 20  age-related changes of the voice Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878 Thyroid Cartilage

8. 8 Cricoid Cartilage – Greek Name meaning ‘ ring like C ricoid cartilage : the skeletal support of the subglottis  completely rigid diameter. S maller cross-sectional area than the trachea A single foreign body that is small enough to pass through the subglottis does not cause total airway obstruction Cricoid Cartilage Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

9. 9 E piglottis : a fibroelastic cartilage Attached anteriorly in the midline to the inner surface of the thyroid cartilage and supported by the hyoepiglottic ligament. The free end of the epiglottis projects into the hypopharynx. Epiglottis Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

10. Fibroelastic Membrane 10 Two important components : The quadrangular membrane supports the supraglottis. The conus elasticus provides support to the vocal fold. Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

11. 11 The muscles of Larynx Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

12. Extrinsic Muscle 12 Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

13. Extrinsic Muscle 13 Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

14. 14 Intrinsic Muscles P osterior cricoarytenoid  the only abductor of the glottis L ateral cricoarytenoid  adductor of the glottis Thyroarytenoid  increasing vocal fold tension, thickness, and stiffness medial thyroarytenoid lateral thyroarytenoid Cricothyroid  increase the length and tension of the vocal folds Interarytenoid  adducts the vocal folds Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

15. Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878 Intrinsic Muscles 15

16. 16 T rue vocal folds  anterior edges of the glottis. P osterior glottis : two arytenoid cartilages and the intervening mucosa. A rytenoids : posterior attachments of both the true and false vocal folds. M ovement of the arytenoids  Opening and closing of the glottis Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

17. 17 The laryngeal cavity is divided into 3 parts in relation to the glottis : Supraglottis Laryngeal inlet  sinus morgagni Glottis Vocal fold +/- 1 cm Subglottis Lower border of glotis  lower border of cricoid Probst R, Grevers G, Iro H. Basic Otorhinolaryngology: A Step-by-Step Learning Guide. second ed. New York: Thieme Publishers; 2017. Laryngeal Cavity

18. Blood supply 18 S upplied by : superior thyroid arteries (branch of the external carotid artery) inferior laryngeal arteries. (branch of the thyrocervical trunk from the subclavian artery) D rained by : superior and middle thyroid veins  internal jugular vein inferior thyroid vein  left brachiocephalic vein. Probst R, Grevers G, Iro H. Basic Otorhinolaryngology: A Step-by-Step Learning Guide. second ed. New York: Thieme Publishers; 2017.

19. Blood supply 19 Lymphatic drainage : laterally  the deep cervical and paratracheal lymph nodes medially  the prelaryngeal and pretracheal lymph nodes. Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

20. Nerve supply 20 S upplied by : I nternal and E xternal branches of the superior laryngeal nerve (SLN) the recurrent laryngeal nerve (RLN) Probst R, Grevers G, Iro H. Basic Otorhinolaryngology: A Step-by-Step Learning Guide. second ed. New York: Thieme Publishers; 2017.

21. Physiology 21 Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

22. Physiology Main function of the larynx a sphincter preventing anything other than air into the lungs Another functions : Coughing Valsalva’s maneuver The regulation of airflow in and out of the lungs. Control of breathing Affect cardiovascular function. 22 Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

23. Cough Ejects mucus and foreign matter from the lungs Helps to maintain patency of the pulmonary alveoli. Cough may be voluntary but more often occurs in response to stimulation of receptors in the larynx or lower respiratory tract. A cough has three phases: 1. Inspiratory 2. Compressive 3. Expulsive. 23 Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

24. Valsalva ’ s Maneuver Forced expiration against a tightly closed glottis The true vocal folds offer more resistance to inspiratory airflow. Enables the larynx to resist very strong expiratory forces. Important in defecation the pressure is transmitted to the abdominal cavity Serves to stabilize the thorax during heavy lifting by the arms. 24 Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

25. Regulation of Airflow The larynx regulate the flow of air in and out of the lungs Two forces contribute to inspiratory opening of the larynx: Longitudinal tension on the laryngeal skeleton (descent of the trachea) Contraction of the posterior cricoarytenoid muscle . 25 Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

26. posterior cricoarytenoid muscle consistently begins to contract before the diaphragm with each inspiration. Active laryngeal abduction is a primary action of breathing The larynx opens more widely during inspiration with increasing effort of breathing and in response to negative upper airway pressure. 26 Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

27. Respiratory Physiology Strong respiratory demand, the posterior cricoarytenoid muscle continues contracting during expiration, after the diaphragm has relaxed. 27 decreased resistance and faster outflow of air shortens the duration of expiration increases the rate of breathing Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

28. Sensory Input to Respiratory Control The larynx is richly supplied with a variety of sensory receptors that exert influences on breathing and cardiovascular function. Laryngeal receptors activated by breathing & influence on the central control of breathing by: Negative pressure receptors, Airflow (cold) receptors “D rive ” receptors Laryngeal receptors also respond to touch and chemical stimuli. 28 Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

29. Circulatory Reflexes Stimulation of the larynx can produce changes in heart rate and blood pressure ( induction of general anesthesia in response to endotracheal intubation ) It may also occur in natural circumstances such as obstructive sleep apnea. The direct result of laryngeal stimulation on blood pressure is hypertension. I f laryngeal stimulation produces significant bradycardia, the indirect result can be hypotension. 29 Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

30. The human voice results from the coordinated interaction of the larynx, lungs, diaphragm, abdominal muscles, throat, neck muscles, lips, tongue, buccinators, and soft palate. Speech consists of three component processes: Phonation  vibration of the vocal folds Resonance  vibration of the rest of the vocal tract Articulation  shaping of the voice into the words by the lips, tongue, palate, and pharynx 30 Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878 Speech

31. Physiology 31 Lucian Sulica. Voice: Anatomy, Physiology, and Clinical Evaluation . In Bailey BJ. Head & Neck Surgery-Otolaryngology. 5 th ed. Lippincot Williams & Wilkins, Philadelphia. 2014:945-957

32. Phonation Sound is produced by the larynx when expiratory airflow induces vibration of free edges of the vocal folds as a result of the interaction of aerodynamic and myoelastic forces. Five conditions must be met to support normal phonation: Appropriate vocal fold approximation Adequate expiratory force Sufficient vibratory capacity of the vocal folds Favorable vocal fold contour Volitional control of vocal fold length and tension 32 Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878 Speech

33. Phonation 33 Lucian Sulica. Voice: Anatomy, Physiology, and Clinical Evaluation . In Bailey BJ. Head & Neck Surgery-Otolaryngology. 5 th ed. Lippincot Williams & Wilkins, Philadelphia. 2014:945-957

34. Phonation Requirements for normal phonation : A. Appropriate vocal fold approximation • Too loose → breathiness • Too tight→ strained voice B. Adequate expiratory force C. Control of length and tension D. Intact layer structure of lamina propria for mucosal mobility E. Adequate vocal fold bulk—( vocalis muscle may become atrophic with aging, neuropathy, or disuse) F. Resonance of vocal tract 34 Lucian Sulica. Voice: Anatomy, Physiology, and Clinical Evaluation . In Bailey BJ. Head & Neck Surgery-Otolaryngology. 5 th ed. Lippincot Williams & Wilkins, Philadelphia. 2014:945-957

35. Resonance Gives the human’s voice’s characteristic Amplify the voice. Vocal training  refining and maximizing resonance Controlled by : altering the shape and volume of the pharynx raising or lowering the larynx, moving tongue or jaw position, varying the amount of sound transmission through the nasopharynx and nose. 35 Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878 Speech

36. Speech Articulation Formation of consonants and vowels Largely controlled by the lips, tongue, palate, and pharynx. 36 Bailey BJ . Head and Neck Surgery Otolaryngology. 5 th Ed. Volume 1 . Philadelphia. JB. Lippincott Williams and Wilkins . 20 14 : 868-878

37. Highlight Patency of the upper airway during breathing depends on active contraction of muscles that dilate the pharynx and open the larynx. Vocal fold motion is controlled by muscles that act on the arytenoid. Tight laryngeal closure is required for the production of an effective cough. The larynx plays a role in controlling the rate of breathing by controlling the rate of airflow into and out of the lungs. Stimulation of the larynx can result in laryngospasm, breathing changes, bradycardia, or hypotension 37

38. Highlight Human speech has three components: phonation (sound production), resonance (amplification and filtering of sound), and articulation (formation of words). The mucosal cover of the vocal fold is highly specialized for phonatory vibration. The pitch of the voice is controlled by changes in length and tension of the vocal folds. The sound of the human voice is greatly determined by the resonance of the upper vocal tract. 38

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