Infrahyoid Muscles Flashcards
Sternohyoid
Origin: posterior surface of manubrium sterni, posterior sternoclavicular ligament, and medial end of clavicle
Insertion: medial part of lower border of body of hyoid bone
Innervation: ansa cervicalis
Blood Supply: SCM and hyoid branches of superior thyroid artery and hyoid branch of lingual artery
Action: depresses larynx and hyoid bone and steadies hyoid bone
Omohyoid
Origin:
- inferior belly: from upper border of scapula and suprascapular ligament and ending in tendon under SCM
- superior belly: from this tendon
Insertion:
- inferior belly: to intermediate tendon
- superior belly: to body of hyoid bone
Innervation: ansa cervicalis
Blood Supply: hyoid branch of lingual artery and SCM branch of superior thyroid artery
Action: steadies hyoid bone and depresses hyoid bone
Thyrohyoid
Origin: oblique line on lamina of thyroid cartilage
Insertion: lower border of body and greater horn of hyoid bone
Innervation: thyrohyoid branch of C1 nerve via hypoglossal nerve (CN XII)
Blood Supply: hyoid branch of superior thyroid artery
Action: depresses larynx and hyoid bone and elevates thyroid cartilage
Sternothyroid
Origin: posterior surface of manubrium sterni below and deep to origin of sternohyoid and edges of first costal cartilage
Insertion: oblique line on lamina of thyroid cartilage
Innervation: ansa cervicalis
Blood Supply: cricothyroid branch of superior thyroid artery
Action: depresses larynx and thyroid cartilage
