Expansion
Those Cats Are Eating
Mnemonic
“Three single, three paired”:
Single: thyroid, cricoid, epiglottis. Paired: arytenoid, corniculate, cuneiform.
The cricoid is the only complete ring in the entire airway, which is why:
- Cricoid pressure occludes the oesophagus behind it during rapid sequence induction
- Cricoid injury is serious, since there is no soft posterior wall to accommodate swelling
- Uncuffed tubes are used in small children, where the cricoid is the narrowest point
The arytenoids are the functional cartilages, since every intrinsic muscle moves them, and rotating them abducts or adducts the cords.
The epiglottis is elastic cartilage, unlike the rest, which are hyaline, and it is therefore the one that does not ossify with age.
Cricothyroidotomy is performed through the cricothyroid membrane, between the thyroid and cricoid cartilages, which is the most superficial point of the airway.
Expansion
- T - Thyroid cartilage
- C - Cricoid cartilage
- A - Arytenoid cartilages, paired
- E - Epiglottic cartilage