Adductors of vocal cord
**Core Concept**
The adductors of the vocal cord are responsible for bringing the vocal folds together, which is essential for speech production and protection of the airway during swallowing. This process involves the contraction of specific intrinsic laryngeal muscles.
**Why the Correct Answer is Right**
The correct answer involves the contraction of the **thyroarytenoid muscle** and the **lateral cricoarytenoid muscle**. The thyroarytenoid muscle relaxes the vocalis muscle and shortens the vocal fold, while the lateral cricoarytenoid muscle adducts the vocal process of the arytenoid cartilage, bringing the cartilages together and thus the vocal folds. This coordinated action results in the closure of the glottis, facilitating speech and preventing aspiration during swallowing.
**Why Each Wrong Option is Incorrect**
**Option A:** The posterior cricoarytenoid muscle is actually the only abductor of the vocal cord, not an adductor. It relaxes the arytenoid cartilages, opening the glottis.
**Option B:** The cricothyroid muscle is a tensor of the vocal fold, lengthening and stretching it, which is not related to adduction.
**Option C:** The arytenoid muscle itself is not directly involved in adduction; rather, it serves as a site of attachment for the lateral cricoarytenoid muscle.
**Clinical Pearl / High-Yield Fact**
During endotracheal intubation, the cricoid pressure (Sellick's maneuver) is applied to prevent gastric aspiration by occluding the esophagus, which relies on the proper functioning of the adductor muscles of the vocal cord.
**Correct Answer: D. Lateral cricoarytenoid and thyroarytenoid muscles.**