Laryngeal cailage forming complete circle is
Ref: BD Chaurasia's HUMAN ANATOMY, Volume 3, 4th edition. Cricoid cailage is shaped like a ring. It encircles the larynx below the thyroid cailage. It is thicker and stronger than the thyroid cailage. The ring has a narrow anterior pa called the arch, and a broad posterior pa called the lamina. The lamina projects upwards behind the thyroid cailage and aiculates superiorly with the arytenoid cailages. The inferior cornua of the thyroid cailage aiculate with the side of the cricoid cailage at the junction of the arch and lamina.
Thyroid
Cricoid
Corniculate
Arytenoid
Head and neck