Kilpnäärmeluu

Kilpnäärmeluu, also known as the cricoid cartilage, is a significant component of the larynx or voice box. It is a singular, ring-shaped piece of cartilage situated below the thyroid cartilage, which is the largest cartilage in the larynx. The cricoid cartilage forms the uppermost part of the trachea, or windpipe, and serves as the base of the larynx. Its unique structure is crucial for maintaining an open airway.

The cricoid cartilage is composed of hyaline cartilage, similar to other laryngeal cartilages. It is a complete ring, unlike the thyroid cartilage, which is C-shaped. This complete ring provides structural support to the trachea, preventing it from collapsing. The cricoid cartilage has a broad posterior portion and a narrower anterior portion. Attached to its superior border are the vocal cords and the thyroid cartilage. Inferiorly, it articulates with the first tracheal ring.

Functionally, the cricoid cartilage plays a vital role in respiration and phonation. It acts as an attachment site for various muscles and ligaments that control the movement of the vocal cords, thereby influencing voice production. Furthermore, its structural integrity is essential for ensuring a continuous and unobstructed passage for air to travel to and from the lungs. In surgical contexts, the cricoid cartilage is an important anatomical landmark, particularly during procedures involving the trachea and thyroid gland.