The cricotracheal ligament connects the cricoid cartilage with the first ring of the trachea[WP]. The caudal border of the cricoid cartilage is joined to the first ring of the trachea by this ligament. It is an extrinsic laryngeal ligament. It resembles the fibrous membrane which connects the cartilaginous rings of the trachea to each other. [ http://en.wikipedia.org/wiki/Cricotracheal_ligament ]