The larynx lies in front of the hypopharynx opposite the third to sixth cervical vertebrae. It moves vertically and in anteroposterior direction during swallowing and phonation. It can also be passively moved from side to side producing a characteristic grating sensation called laryngeal crepitus.
Muscles of larynx
Posterior cricoarytenoid, lateral cricoarytenoid, inter arytenoid, thyroarytenoid, cricothyroid, and vocalis.
Elevators: Stylopharyngeus, salpingopharyngeus, palatopharyngeal, and thyrohyoid.
Depressors: Sternohyoid, sternothyroid, and omohyoid.
Physiology of nose
1: Protection of lower airways.
4: Fixation of the chest
Inflammation of larynx
It may be acute or chronic.
Acute: Usually follows upper respiratory infection. To begin with, it is viral in origin but soon bacterial invasion takes place. Noninfectious inflammation is due to vocal abuse, allergy, thermal or chemical burns to the larynx due to inhalation or ingestion of various substances or laryngeal trauma such as endotracheal intubation.
1: Hoarseness which may lead to complete loss of voice.
2: Discomfort or pain in the throat, particularly after talking.
3: Dry, irritating cough which is usually worse at night.
4: General symptoms of a head cold, rawness or dryness of throat, malaise, and fever if laryngitis has followed viral infection of the upper respiratory tract.
1: Vocal rest and avoidance of smoking and alcohol.
2: Cough sedatives and antibiotics.
3: Steam inhalations and analgesics.
Chronic: It is a diffuse inflammatory condition symmetrically involving the whole larynx.
1: It may follow incompletely resolved acute simple laryngitis.
2: Smoking and alcohol.
3: Persistent trauma of cough as in chronic lung diseases.
4: Vocal abuse.
1: Hoarseness and constant hawking.
2: Discomfort in the throat.
3: Dry and irritating cough.
1: Eliminate infection of the upper or lower respiratory tract.
2: Avoidance of irritating factors(smoking, alcohol, or polluted environment)
3: Voice rest and speech therapy.
4: Steam inhalations and expectorants.
Congenital lesions of the larynx
2: Congenital subglottic stenosis.
3: Congenital vocal cord paralysis.
5: Laryngeal cyst.
6: Laryngeal web.
Stridor: Stridor is noisy respiration produced by turbulent airflow through narrowed air passages. It may be heard during inspiration, expiration, or both.
Inspiratory stridor is produced in obstructive lesions of supraglottic or pharynx, e.g. laryngomalacia or retropharyngeal abscess.
Expiratory stridor is produced in lesions of thoracic trachea, primary and secondary bronchi.
Biphasic stridor is seen in lesions of the glottis, subglottis, and cervical trachea.
Tumors of larynx
They appear symmetrically on the free edge of the vocal cord, at the junction of anterior one-third with the posterior two thirds as this is the area of maximum vibration of the cord and thus subject to maximum trauma.
Patients with vocal nodules complain of hoarseness. Vocal fatigue and pain in the neck on prolonged phonation are other common symptoms.
Early cases of vocal nodules can be treated conservatively by educating the patient in the proper use of voice. Surgery is required for large nodules or nodules of long-standing in adults. Speech therapy and re-education in voice production are essential to prevent their recurrence.
1: Squamous papillomas
4: Granular cell tumor
5: Rare benign laryngeal tumors