They are attached posteriorly to the arytenoid cartilages, and anteriorly to the thyroid cartilage. The cut overlies the sternum, ribs, and connecting costal cartilages. Inflammation occurs in the laryngeal, tracheal and bronchial cartilages. The nasal cartilages are the septal, lateral, major alar, and minor alar cartilages. Without the rib cages, costal cartilages, and intercostal muscles, the lungs would collapse. This Greek word means literally "below the cartilage" which refers to the costal cartilages. During the opening stage, two abductor artytenoideae muscles swing arytenoid cartilages and the glottis walls. Arches 4 and 6 produce the laryngeal cartilages. Involvement of the rib cartilages results in costochondritis. The major and minor cartilages are also known as the greater and lesser alar cartilages. The nasal vestibule is the frontmost part of the nasal cavity, enclosed by cartilages. This structure is formed by the junction between the lateral and major cartilages. The arytenoid cartilages are held in firm apposition in this voice register also. The muscles attached to the arytenoid cartilages control the degree of opening. The positions of the vocal folds are achieved by movement of the arytenoid cartilages.