The cricoid cartilage
, or simply cricoid
(from the Greek krikoeides
meaning "ring-shaped"), is the only complete ring of cartilage
around the trachea
It sits just inferior to the thyroid cartilage
in the neck
, and is joined to it medially by the median cricothyroid ligament
and postero-laterally by the cricothyroid joints. Inferior
to it are the rings of cartilage around the trachea (which are not continuous - rather they are C-shaped with a gap posteriorly). The cricoid is joined to the first tracheal ring by the cricotracheal ligament
, and this can be felt as a more yielding area between the firm thyroid cartilage and firmer cricoid.
It is also anatomically related to the thyroid gland; although the thyroid isthmus is inferior to it, the two lobes of the thyroid extend superiorly on each side of the cricoid as far as the thyroid cartilage above it.
The posterior part of the cricoid is slightly broader than the anterior and lateral parts, and is called the lamina, while the anterior part is the band; this may be the reason for the common comparison made between the cricoid and a signet ring.
The function of the cricoid is to provide attachments for the various muscles
, cartilages, and ligaments
involved in opening and closing the airway
and in speech production
It is made of hyaline cartilage
, and so can become calcified
or even ossified
, particularly in old age.
a patient under general anesthesia
prior to surgery, the anesthesiologist
will press on the cricoid cartilage to compress the esophagus behind it so as to prevent gastric reflux
Gastric reflux could cause aspiration if this is not done considering the general anesthesia can cause relaxation of the gastro-esophageal sphincter allowing stomach contents to ascend through the esophagus into the trachea.