## Laryngeal Cartilage Framework **Key Point:** The cricoid cartilage is the only laryngeal cartilage that forms a complete ring around the larynx, resembling a signet ring with an anterior arch and posterior lamina. ### Structural Features of Laryngeal Cartilages | Cartilage | Shape | Encirclement | Key Features | |-----------|-------|--------------|---------------| | Cricoid | Signet ring | **Complete ring** | Anterior arch, posterior lamina; articulates with thyroid and arytenoids | | Thyroid | Shield-like | Incomplete (open posteriorly) | Largest cartilage; forms laryngeal prominence (Adam's apple) | | Arytenoid | Pyramidal | No | Paired; sit on cricoid lamina; articulate with vocal cords | | Epiglottis | Leaf-shaped | No | Elastic cartilage; covers laryngeal inlet during swallowing | **High-Yield:** The cricoid cartilage is clinically significant because: - It is the narrowest part of the pediatric airway (subglottic region) - It is the landmark for cricothyrotomy in emergency airway management - It is the only complete ring, making it the most rigid support structure **Clinical Pearl:** In children, the subglottic trachea (just below the cricoid) is the narrowest point of the entire airway, unlike adults where the glottis is narrowest. This is why croup (subglottic laryngitis) causes stridor in children. ### Anatomical Relationships The cricoid cartilage articulates with: 1. Thyroid cartilage superiorly via cricothyroid joints (allow rocking and gliding) 2. Arytenoid cartilages posteriorly via cricoarytenoid joints (allow rotation and sliding) 3. First tracheal ring inferiorly [cite:Gray's Anatomy 41e Ch 33] 
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