Thyrohyoid Muscle Anatomy

The thyrohyoid muscle appears as a quadrilateral muscle situated in the anterior neck region. This muscle essentially functions as a continuation of the omohyoid muscle, though it maintains distinct anatomical characteristics. The muscle extends from the thyroid cartilage to the hyoid bone, creating a bridge between these two important laryngeal structures.

The thyrohyoid appears to be the continuation of the sternothyroid muscle, running superiorly from the oblique line of the thyroid cartilage to the hyoid.

Thyrohyoid Muscle Anatomy

The Thyrohyoid muscle originates specifically from the oblique line on the lamina of the thyroid cartilage. From this point, its fibers course superiorly and slightly laterally to insert into the greater cornu and lateral border of the body of the hyoid bone.

The thyrohyoid muscle receives its primary innervation from the first cervical nerve (C1), which reaches the muscle through a branch of the hypoglossal nerve. This unique innervation pattern differs from other infrahyoid muscles, highlighting its distinct developmental origin and functional significance.

The arterial supply to the thyrohyoid muscle primarily derives from branches of the superior thyroid artery, with additional contributions from the superior laryngeal artery. Venous drainage occurs through corresponding vessels that ultimately connect to the internal jugular vein system. This rich vascular network ensures adequate blood supply for muscle function and healing after injury or surgery.

The thyrohyoid muscle plays a fundamental role in laryngeal movement and swallowing mechanics. When the hyoid bone is fixed, contraction of the thyrohyoid muscle elevates the thyroid cartilage, contributing to laryngeal elevation during swallowing. Conversely, when the thyroid cartilage is fixed, the muscle can depress the hyoid bone, facilitating certain phases of swallowing and speech production.

In the context of deglutition, the thyrohyoid muscle works synergistically with other suprahyoid and infrahyoid muscles to coordinate the complex movements required for safe and effective swallowing. This coordinated action helps protect the airway during swallowing by contributing to epiglottic movement and laryngeal closure.

Clinical Importance

Dysfunction of this muscle can contribute to dysphagia and voice disorders.

During thyroid surgery, careful attention must be paid to preserve the neurovascular supply to the thyrohyoid muscle, as damage can result in postoperative swallowing difficulties. Additionally, the muscle serves as an important surgical landmark during anterior neck procedures, helping surgeons navigate this anatomically complex region.

References & More

1. Clinically Oriented Anatomy, 8th Edition https://shop.lww.com/Clinically-Oriented-Anatomy/p/9781975140403
2. Mnatsakanian A, Al Khalili Y. Anatomy, Head and Neck, Thyroid Muscles. [Updated 2023 Jul 24]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: Pubmed