**Question:** All are elevators of larynx except:

A. Cricothyroid muscle
B. Thyroarytenoid muscle
C. Laryngeal branch of recurrent nerve
D. Adductor muscles of larynx

**Core Concept:**
The larynx is a part of the respiratory system that plays a crucial role in maintaining airway patency, producing vocalization, and protecting the airway from aspiration. Elevators of the larynx are muscles that help to raise the larynx, which is essential for maintaining airway patency and facilitating voice production.

**Why the Correct Answer is Right:**
The correct answer is D, the adductor muscles of the larynx. Adductor muscles are those that pull the vocal cords together, which is an opposite action to elevators. In this context, the adductor muscles are:

1. Adductor cricothyroid muscle (Option D): This muscle is responsible for pulling the cricothyroid membrane (a junction between thyroid and cricoid cartilage) closer, which in turn adducts the vocal cords.
2. Adductor muscles of the arytenoids (not mentioned in options): The arytenoids are the two small cartilaginous bodies on the posterior aspect of the aryepiglottic folds. The adductor muscles of the arytenoids pull the arytenoids closer, which adducts the vocal cords.

**Why Each Wrong Option is Incorrect:**

A. **Cricothyroid muscle (Option A):** This muscle is an elevator of the larynx, not an adductor. When the cricothyroid muscle contracts, it elevates the thyroid cartilage, which raises the larynx and helps in maintaining airway patency.

B. **Thyroarytenoid muscle (Option B):** This muscle is also an elevator of the larynx, similar to the cricothyroid muscle. When the thyroarytenoid muscle contracts, it elevates the arytenoid cartilage, which raises the larynx and aids in maintaining airway patency.

C. **Laryngeal branch of recurrent nerve (Option C):** The laryngeal branch of the recurrent nerve supplies motor neurons to various muscles of the larynx. Although this options refers to a structure involved in laryngeal movement, it does not specifically address the role of the cricothyroid and thyroarytenoid muscles as adductors of the larynx.

**Clinical Pearl:** Understanding the anatomy and function of the muscles involved in laryngeal movement is crucial in diagnosing and managing airway issues and voice disorders. Understanding the role of adductors and elevators of the larynx helps in diagnosing and managing conditions like hoarseness, stridor, and airway obstruction caused due to misalignment of vocal cords.