functions of larynx

1. Dr Manpreet Singh Nanda
Associate Professor ENT
MMMC&H Solan

2. Functions of Larynx
 Protection of lower airways (1)
 Phonation and Speech (2)
 Respiration
 Fixation of chest
 Helps in promoting venous return

3. Protection of lower respiratory
tract
 SPHINCTER CLOSURE OF LARYNGEAL
OPENINGS DURING SWALLOWING
 1st tier – aryepiglottic folds, epiglottis, arytenoids
 2nd tier – false cords
 3rd tier – true cords
 Due to contraction of adductor muscles

4.  CESSATION OF RESPIRATION TEMPORARY
 IX CN (Swallowing reflex – when food comes into
contact with oropharynx)
 COUGH REFLEX
 Barking sensation at entry of FB and food particles
which are coughed out

5. Phonation and Speech
 Theories –
 1. Aerodynamic theory of phonation
 2. Myoelastic theory of phonation
 3. Neurochronaxic theory of phonation
 PHASES –
 Pulmonary phase
 Laryngeal phase
 Supraglottic or Oral Phase

6. Pulmonary Phase
 Air breathed in
 Inflation of lungs
 Increased air pressure
 Expulsion of air
 (due to contraction of thoracic and abdominal
muscles)

7. Laryngeal Phase
 Air pressure
 Opens adducted vc
 Small puffs of air between vocal cords
 Vibration of elastic cords (oscillatory motion of
membranous part of vc)
 Fundamental note (voice) formed

8. Supraglottic or oral phase
 Modifies laryngeal sound
 Resonation – modification/amplification of sound
 Oral cavity, pharynx, nasal cavity, PNS (Supraglottic
tract)
 Articulation – words of sentence (speech) formed by
muscles of tongue, lips, teeth, gums, palate

9.  Intensity of sound – controlled by air pressure in
lungs
 Pitch of sound – controlled by vocal cord vibration
which changes with change in length, breadth and
elasticity of vc
 Quality of speech – depends on resonance and
articulation

10. Respiration
 Adduction of vc – expiration
 Abduction of vc – inspiration
 Regulates flow of air into lungs

11. Fixation of chest
 Closed larynx -> built up of air pressure -> chest wall
fixed -> main thoracic and abdominal muscles act best
-> sternous work
 Digging, pulling, climbing, coughing, defaecation,
micturition, child birth, straining

12. Hoarseness of voice
 Def – Change in voice or rough and unpleasant voice
due to vocal cord lesions leading to faulty
approximation of vocal cords
 M.C Symptom
 Muffled voice – hot potato voice
 Seen in lesions of laryngopharynx and tongue base,
vocal cords not involved
 Breathy voice – seen in vc paralysis due to escape of
air between vc

13. Etiology
 Laryngeal
 Congenital – webs, cysts
 Infective – acute, chronic, TB, syphilis
 Trauma – injury, intubation, fumes inhalation
 Acid reflux
 Tumours – benign, malignant (elderly >2 weeks)
 Voice abuse
 Neurological – vc paralysis
 Psychological
 Irradiation
 Arthritis of cricoarytenoid joint
 Vocal cord nodule, polyp, laryngocele

14.  Endocrine
 Hypothyroidism, RA, Hyperparathyroidism, Dibetes
 Oesophageal – Malignancy
 Cervical and Mediastinal – RLN paralysis
 PATHOLOGY – interference in –
 Movement of vc
 Approximation of vc
 Mass of vc
 Tension of vc

15. Management
 HISTORY TAKING
 Age – young - infection, old – malignancy
 Sex – male – malignancy
 Occupation – voice users, workers (fumes)
 Onset – sudden with gradual improvement – vc paralysis
 Duration – short – inflammatory
 Progression – long duration slow progress (neoplastic)
long duration rapid progressive (malignancy)
 Past history – procedures, radiation therapy
 Habits – smoking, drinking

16.  GPE
 Nutrition – cachexia – malignancy, TB
 Lymph nodes – hard (malignancy)
 Thyroid
 LOCAL
 ENT
 IDL
 CVS/RS/CNS

17. Investigations
 X Ray larynx, chest
 CT Scan
 Flexible laryngoscopy (OPD)
 DL Scopy and Biopsy
 Microlaryngoscopy ( op microscope)
 Barium Swallow (ca oesophagus)
 Bronchoscopy and Oesophagoscopy
 Thyroid Scan / TFT
 Blood – Hb, TLC, DLC, RBS, ESR, VDRL
 Urine
 Mantoux test

18. Treatment
 Treat the cause
 Voice rest – avoid abuse and whispering
 Steam inhalations with inhalant capsules (menthol,
camphol, eucalyptus oil) – soothes vc, reduces
congestion
 Antibiotics - infection
 Anti inflammatory – oedema and congestion
 Speech therapy

19. Voice and Speech disorders
 Speech disorders
 - Aphasia and Dysphasia
 - Dysarthria
 - Stammering or Stuttering

20. Dysphasia and Aphasia
 Dysphasia – Impaired comprehension or production
of speech due to lesions affecting cortical speech
centre in dominant cerebral hemisphere
 Aphasia – loss of speech
 TYPES
 - Sensory or receptive
 - Motor or expressive
 - Conductive
 - Mixed or total
 - Amnesic or nominal

21. Sensory dysphasia or Wernicke’s
aphasia
 Receptive
 Impaired comprehension of words
 Patient unaware
 Types –
 1. Auditory (word deafness)
 Cant comprehend spoken words, hearing normal, lesion in
auditory area
 2. Visual (word blindness)
 Cant comprehend meaning of written words, vision normal
 3. Agrammatism – Severe

22. Motor dysphasia or Broca’s aphasia
 Expressive
 Difficulty in speech production or language output
(writing and sign)
 Knows what to say cant speak
 Understands written words cant read
 Patient aware
 Lesion in cortical motor speech broca’s area
 Can read and hear normally

23.  CONDUCTIVE APHASIA
 Skips words or repeat words
 Cant repeat examiner command
 Lesion in arcuate fasciculus (connects)
 PARAPHASIA – Replacing one word with another
 AMNESIC OR NOMINAL APHASIA – Difficulty in
naming objects or persons seen, held or felt
 MIXED OR TOTAL APHASIA – All aspects of speech
and communication are impaired

24. Dysarthria
 Def – Disturbance of articulation due to lesions
affecting cranial nerves, muscles, joints, ligaments
responsible for speech leading to faulty working of
lips, tongue, palate, pharynx and larynx
 Etiology –
 Supranuclear lesions, nuclear lesions, infranuclear
lesions, muscular lesions, nerve palsy

25. Stammering or Stuttering
 Functional speech disorder
 Neurological movement disorder in which abnormal,
involuntary and inappropriate use of speech muscles
results in dysfluency
 Cause – Psychogenic, due to increased muscle tension in 3
subsystems of speech – lungs, larynx and supra laryngeal
tract
 Too much attention or reprimands to childhood dysfluency
between 2 to 4 years
 Common in pre school years
 Common in boys

26. Clinical Features
 Hesitation to initiate speech
 Repetition
 Prolongation
 Blocks in speech flow
 Secondary features – facial grimacing, eye blink,
abnormal head movements
 Relieving factors – singing, shouting
 Aggravating factors – public speech, personal
interview

27. Treatment
 Speech therapy
 Psychotherapy – assurance and counselling of both
parents and patients, educate not to over react
 Anti depressants
 Botulinum toxin inj
 “ Speech easy” ear device – delayed auditory feedback

28. Dysphonia plica ventricularis
 False cord voice
 Ventricular dysphonia
 False cords take over function of true vc
 Etiology
 - Psychogenic and tense individuals
 - Organic causes- true vc paralysis, fixation, excision
causing compensation
 C/F
 - Rough, harsh and low pitched voice
 - Late onset in psychogenic cause
 - Diplophonia (double voice)

29.  Signs
 - False cords approximate on phonation partially or
completely
 - False vc red and thickened
 - Obscure view of true vc
 Investigation – stroboscopy
 Treatment
 - Voice therapy
 - Psychogenic therapy
 - Organic cause difficult to treat ( laser excision)

30. Functional/hysterical aphonia
 Sudden complete loss of voice seen in young females
 Etiology
 - emotional social problems, anxiety
 - age gp mc 15 to 30 yrs
 C/F
 Sudden and complete loss of voice
 Whisper, cough, laugh and cry are normal
 No aspiration ( diff from adductor palsy)
 Muteness ( refusal to speak)
 Signs – vc in abducted position but adduct on coughing
 Treatment – reassurance and psychotherapy

31. Puberphonia/Pubophonia
 Mutational/Functional falsetto voice
 Failure to change childhood high pitched voice to low pitched male
voice after puberty in boys
 Etiology
 Emotionally immature boys, insecure, too much attached to mother or
sister
 Hormonal disturbance
 Childhood asthma (doubtful)
 Pathology
 Hyperkinetic function and spasm of cricothroid muscle
 C/F
 Cracking of voice in males at puberty
 High pitched and weak voice
 Thin, shy and insecure patients

32.  Signs
 Normal larynx
 Oval or elliptical slit glottis
 Posteriorly formed mutational triangle (due to partial
closure of vocal process)
 Investigations – Stroboscopy
 Treatment
 Speech therapy
 Psychotherapy
 Train to produce low pitch voice by pressing thyroid
prominence backwards and downwards (relaxes vc) –
Gutzmann pressure test

33. Habitual dysphonia
 Gradual onset hoarseness which becomes worst after
period of time
 Etiology
 Prolonged habitual misuse or abuse of vc like shouting
and screaming or long use
 Signs
 Oedema and inflammation of vc
 Treatment
 Voice therapy

34. Mogiphonia
 Phonic spasm in professional voice users when they appear
in public
 Etiology – psychogenic
 C/F
 Starts normal but later cant speak
 Signs
 Adducted vc
 Treatment
 Psychotherapy
 Speech therapy
 Voice rest

35. Phonoasthenia
 Phonoasthesia/Myasthenia of Larynx
 Functional weakness of voice due to fatigue of phonatory
muscles mainly thyroarytenoid and interarytenoid
 Etiology
 - Vocal abuse
 - Laryngitis
 C/F – easy fatigue voice
 IDL –
 - Hyperaemia of vc
 - Elliptical space between vc (thyroarytenoid)
 - Triangular gap in post commissure (interarytenoid)
 - Keyhole appearance (both)
 Treatment – total voice rest and vocal hygiene

36. Rhinolalia
 Nasal speech or nasal intonation of speech
 Rhinolalia clausa
 Hyponasality
 Blockage of nose or nasopharynx due to rhinosinusitis, allergic rhinitis,
polyp or mass, adenoids, functional
 Lack of resonance of words resonated in nasal cavity like m , n , ng
 Rhinolalia aperta
 Hypernasality
 Failure of nasopharynx to cut off from oropharynx or extra openings
between oral and nasal cavities due to short soft palate, soft palate
paralysis, palatal perforation, after adenoidectomy and functional
 Nasal resonance for all the words even those having little resonance

37. Spasmodic/Spastic dysphonia
 Focal dystonia of larynx/ laryngeal spasm
 Dystonia – abnormal involuntary movements
 Def – stress induced laryngeal motion disorder resulting in
alternate harsh and soft voice
 Types – adductor (irregular hyperadduction), abductor
(intermittent abduction), mixed
 C/F
 At rest – normal vc
 When speak – abnormal function
 Rapid alteration in pitch and loudness of voice (vocal tremors)
 Adductor – choked, strained, strangulated, monotonous voice
 Abductor – breathy and effortful voice

38.  Aggravated by – stress
 Relieved by – sedation, alcohol, singing, yawning,
shouting
 Also seen spasm of eyelids, jaw and tongue
 Treatment
 - voice therapy
 - sedatives
 - RLN sectioning
 - Botulinum injection

39. Tourette’s syndrome
 Tic disorder
 Involuntary vocalization of articulate sounds
 Along with other tics (nose, tongue)
 C/F
 Onset – childhoood or adolescence
 OCD
 Treatment
 Benzodiazepines
 Phenothiazines (haloperidol)
 Botulinum injections

40. Laryngeal vertigo
 Attacks of vertigo with temporary unconsciousness
following spasm of vocal cords
 Seen in emotionally instable males
 C/F
 Giddiness or light head
 Pale and cyanosis
 Momentary loss of conscious
 But no tremors and convulsions (epilepsy)

41. Vocal hygiene
 Def – Habits to maintain proper functioning of vocal cords
especially those with voice disorders
 Habits –
 - Voice rest
 - avoid voice abuse
 - avoid smoking and dust
 - avoid spicy food (LPR)
 - avoid whispering, forceful coughing, throat clearing
 - avoid drying potential medications like anti histaminics
 - treat mouth breathing
 - increased fluid intake
 - avoid speaking during URTI
 - avoid vigorous exercise leading to noisy breathing