耳鼻喉科Otolaryngology topic fourteen: Larynx & pharynx

Larynx & pharynx

1. Anatomy

Larynx

-- laryngeal cartilage: x 9

-- cricoid cartilage: the only cartilage 360° surrounding the trachea 

-- arytenoid: 4 intrinsic laryngeal muscles attached

Pharynx

-- narrowest at cricopharyngeal m. (upper esophageal sphincter)

2. Microstructure for phonation

-- cover: epithelium

-- transition: lamina propria

-- body: thyroiarytenoid

--> mucosa wave

3. Innervation

-- superior laryngeal n. external branch: CT muscle

-- recurrent laryngeal n. : all the other intrinsic muscles

4. Swallowing: 5 steps

-- soft palate closure

-- larynx elevation/ anterior movement

-- epiglottis 

-- constrictor muscle

-- crycopharyngeal m. relaxation

*** Right side bronchus: more straight, beware of choking with foreign body

5. Congenital abnormalies

-- laryngomalacia: cartilage/soft tissue collapsing inward during inhalation 

-- vocal cord paralysis: children--> bilateral, combined with other CNS defects 

6. Acquired diseases

-- acute laryngitis: virus infection

-- acute epiglottitis: Hemophilus influenza, airway obstruction, 2~6 y/o children/immunocompromised

-- laryngopharyngeal reflux(LPR): foreign body sensation, granuloma(LPR induced), need 24 hr pH monitor

-- Reinke's edema(polypoid vocal cord): @superficial lamina propria, smokers

-- laryngotracheal trauma: external, iatrogenic(bilateral)

-- laryngotracheal stenosis

-- foreign body ingestion (2/3)/aspiration(1/3):@ cricopharygeal m., 2~4 y/o

               --> pins

               --> peas

               --> coins

               --> meat, bones 

7. Head and neck cancers

-- male >> female : most obvious difference in esophageal cancer

-- 10~20% distal metastasis, mostly to lungs

-- treatment: anterior parts, ex: oral cavity--> surgery; naso/oropharynx: CCRT