The cricoid cartilage , or simply cricoid (from the Greek krikoeides meaning "ring-shaped") or cricoid ring, is the only complete ring of cartilage around the trachea. It forms the back part of the voice box and functions as an attachment site for muscles, cartilages, and ligaments involved in opening and closing the airway and in producing speech.

Anatomy

The cricoid cartilage is the only laryngeal cartilage to form a complete circle around the airway. It is smaller yet thicker and tougher than the thyroid cartilage above.

It articulates superiorly with the thyroid cartilage, and the paired arytenoid cartilage. Inferiorly, the trachea attaches onto it.

Cricoid arch

The cricoid arch is the curved and vertically narrow anterior portion of the cricoid cartilage. Anteriorly, it measures 5–7 mm superoinferiorly; it becomes wider on eithers side towards its transition into the cricoid lamina of that side. The American Heart Association still advocates the use of cricoid pressure during resuscitation using a BVM, and during emergent oral endotracheal intubation. However, recent research increasingly suggests that cricoid pressure may not be as advantageous as once thought. The initial article by Sellick was based on a small sample size at a time when high tidal volumes, head-down positioning, and barbiturate anesthesia were the rule.

Cricoid pressure may frequently be applied incorrectly. Cricoid pressure may frequently displace the esophagus laterally, instead of compressing it as described by Sellick. Several studies demonstrate some degree of glottic compression reduction in tidal volume and increase in peak pressures. Based on the current literature, the widespread recommendation that cricoid pressure be applied during every rapid sequence intubation is quickly falling out of favor.

Gastric reflux could cause aspiration if this is not done considering the general anesthesia can cause relaxation of the gastroesophageal sphincter allowing stomach contents to ascend through the esophagus into the trachea.

A medical procedure known as a cricoidectomy can be performed in which part or all of the cricoid cartilage is removed. This is commonly done to relieve blockages within the trachea.

Fractures of the cricoid cartilage can be seen after manual strangulation also known as throttling.

Additional images

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File:Larynx detailed.jpg|Cricoid cartilage.

File:Illu larynx.jpg|Larynx

File:Gray950.png|The cartilages of the larynx. Posterior view.

File:Gray952.png|Ligaments of the larynx. Posterior view.

File:Gray953.png|Sagittal section of the larynx and upper part of the trachea.

File:Slide4e.JPG|Cricoid cartilage

</gallery>

See also

  • Tracheotomy

References

  • Illustration at nda.ox.ac.uk
  • - "Skeleton of the larynx."
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