The cricoid cartilage, or simply cricoid (from the Greek krikoeides meaning "ring-shaped"), is the only complete ring of cartilage around the trachea...
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
Cricoid is made up of hyaline cartilage..height of anterior lamina is 3-7mm and posterior lamina is about 20-30mm height..post surface of cricoid the post cricoarytenoid muscles are attached.When intubating a patient under general anesthes...ia prior to surgery, the anesthesiologist will press on the cricoid cartilage to compress the esophagus behind it so as to prevent gastric reflux from occurring: this is known as the Sellick manoeuvre
During Sellick manoeuvre cricoid pressure should not be more than 30N ...or can lead to fracture of cricoid cartilage..even linear fracture of the cricoid cartilage causes some resorption of cartilage and reduction of caliber of airway at t...he same level..resorption of cricoid cartilage can also be occured,if tracheostomy tube placed between cricoid and 1st ring...AS A GENERAL RULE INJURY TO CRICOID CARTILAGE HAS HIGEST INCIDENCE OF AIRWAY COMPROMISE...LEVEL OF CRICOID IS BETWEEN 5TH & 6TH CERVICAL VETEBRAL...