Which is the signet ring-shaped laryngeal cartilage?

Appeared in: PGICH Noida NO-2025

Explanation

The cricoid cartilage is uniquely shaped like a signet ring, featuring a narrow anterior arch and a broad posterior lamina.
It is the only laryngeal cartilage that forms a complete, unbroken circle, providing essential structural support to the airway.
This complete ring structure prevents the collapse of the airway at the critical junction between the larynx and the trachea.

Option A: The cuneiform cartilages are small, paired, club-shaped cartilages embedded within the aryepiglottic folds. They provide support but are not ring-shaped.
Option C: The thyroid cartilage is the largest laryngeal cartilage, but it is shield-shaped and open posteriorly. It does not form a complete ring.
Option D: The arytenoid cartilages are paired and pyramid-shaped. They sit on the cricoid cartilage and are essential for vocal cord movement, not for forming a ring.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Anatomy of Laryngeal Cartilages as background academic context rather than a clinical decision trigger.
The cricoid cartilage is a critical landmark for emergency airway procedures. Applying posterior pressure on it (the Sellick maneuver) can occlude the esophagus and prevent aspiration of gastric contents during endotracheal intubation.
In a 'can't intubate, can't ventilate' scenario, a cricothyrotomy is performed by making an incision through the cricothyroid membrane, which lies between the thyroid and cricoid cartilages. Palpating the cricoid is a vital skill.
What if? If a patient has a suspected cervical spine injury, the Sellick maneuver (cricoid pressure) is still often applied during rapid sequence intubation, but it must be done with care to avoid any movement of the neck. This highlights the need to balance airway protection with spinal precautions.

How to Approach the Question

This is a factual recall question testing knowledge of anatomy.
Identify the key descriptor in the question stem: 'signet ring-shaped'.
Mentally review the shapes of the different laryngeal cartilages.
Evaluate each option: The thyroid cartilage is a 'shield', the arytenoids are 'pyramids', and the cuneiforms are small 'clubs'.
Conclude that only the cricoid cartilage matches the 'signet ring' description, as it's the only complete ring in the larynx.

Concept Tested & Keywords

Qv761jZZCzBsQj6dagCGrQ

E6 Anatomy Applied Ashalatha 4e p. 94-96

Practise the full PGICH Noida NO-2025

Attempt every question from this paper in a timed mock, then review the full solution for each one.