Which of the following muscle produces abduction of vocal cord? (Repeat)
First, I remember that the larynx has muscles responsible for moving the vocal cords. Abduction means moving them apart, which is important for breathing. The main muscles involved in vocal cord movement are the posterior cricoarytenoid muscles. These are the primary abductors. The other muscles like thyroarytenoid are adductors or involved in other movements.
Wait, the posterior cricoarytenoid muscles are the ones that abduct the vocal cords. The lateral cricoarytenoid and thyroarytenoid are adductors. The interarytenoid also adds. So if the question is asking about abduction, then the correct answer should be posterior cricoarytenoid. The options might have included this as one of the choices.
Since the user mentioned it's a repeat question, maybe in their original question the options were A to D with these muscles listed. But since the options aren't provided here, I have to rely on standard anatomy. The key point is that the posterior cricoarytenoid is the main abductor. So if the correct answer is, say, option C, then the explanation would focus on that.
Now, the core concept here is the anatomy of laryngeal muscles and their functions. The posterior cricoarytenoid muscles are the primary abductors, which is crucial for maintaining an open airway. The incorrect options would include adductors or other muscles not involved in abduction.
For the clinical pearl, it's important to note that damage to these muscles can lead to vocal cord paralysis, affecting breathing and voice. Also, the posterior cricoarytenoid is innervated by the recurrent laryngeal nerve, which is a high-yield fact for exams.
Putting this together, the correct answer is the posterior cricoarytenoid muscle. Each incorrect option would be another muscle that doesn't perform abduction. The explanation should clarify their roles to avoid confusion.
**Core Concept**
The posterior cricoarytenoid muscle is the primary abductor of the vocal cords, essential for maintaining airway patency during respiration. It acts by rotating the arytenoid cartilages laterally, widening the glottis.
**Why the Correct Answer is Right**
The posterior cricoarytenoid muscle abducts the vocal cords by rotating the arytenoid cartilages anteriorly and laterally. This action increases the size of the glottis, allowing unobstructed airflow. It is innervated by the recurrent laryngeal nerve (a branch of the vagus nerve), making it critical for both breathing and phonation. No other laryngeal muscle performs abduction as effectively.
**Why Each Wrong Option is Incorrect**
**Option A (e.g., Thyroarytenoid):** This muscle adducts and tenses the vocal cords; it does not abduct them.
**Option B (e.g., Lateral cricoarytenoid):** This muscle adducts the vocal cords by rotating the arytenoids medially.
**Option D (e.g., Interarytenoid):** These muscles adduct the posterior vocal cord segments, narrowing the glott