Head and Neck Muscles Flashcards
Action of Digastric
Depresses mandible against resistance
Elevates and steadies hyoid during swallowing and speaking
Action of Geniohyoid
Pulls hyoid anteriorly and superiorly; shortens floor of mouth; widens pharynx
Action of Masseter
Elevates mandible, closing jaw; superficial fibers make limited contribution to protusion of mandible
Action of Longus Colli
Flexes neck with rotation to opposite side (torsion) if acting unilaterally
Action of Longus Capitis, Rectus Capitis Anterior and Anterior Scalene
Head flexion
Action of Rectus Capitis Lateralis
Flexion and stability of head
Action of Middle Scalene
Lateral flexion of neck, elevates 1st rib during forced inspiration
Action of Mylohyoid
Elevates hyoid, floor of mouth, and tongue during speaking and swallowing
Action of Omohyoid
Depresses, retracts, and steadies hyoid
Action of Splenius Capitis
Ipsilateral flexion of neck and bilateral extension of vertebral column and head
Action of Sternocleidomastoid
Lateral flexion of neck and rotates face towards opposite side. Extends neck at atlantooccipital joints, flexes cervical vertebrae so chin approaches manubrium, assists in chin protrusion and pump handle action of deep respiration
Action of Sternohyoid
Depresses hyoid after elevation during swallowing
Action of Sternothyroid
Depresses hyoid and larynx
Action of Temporalis
Elevates mandible, closing jaw; posterior, more horizontal fibers are primary retractors of mandible
Action of Stylohyoid
Elevates AND retracts the hyoid, elongating the floor of the mouth
Action of Thyrohyoid
Depresses hyoid and elevates larynx
Innervation of Anterior Belly of Digastric
Inferior alveolar nerve via Mandibular nerve (V3)
Innervation of Anterior Scalene
Spinal nerves C4-C6
Innervation of Geniohyoid
CI spinal nerve via hypoglossal nerve (XII)
Innervation of Longus Capitis
Anterior rami of C1-C3
Innervation of Mylohyoid
Inferior alveolar nerve via Mandibular nerve (V3)
Innervation of Longus Colli
Anterior rami of C2-C6
Innervation of Middle Scalene
Anterior rami of C4-C6
Innervation of Omohyoid
Ansa Cervicalis (C1-C3)
Innervation of Posterior Belly of Digastric
Digastric branch of facial nerve (VII)
Innervation of Posterior Scalene
Branches of Spinal Nerves C4-C6
Innervation of Rectus Capitis Anterior
Branches from loop between C1-C2
Innervation of Rectus Capitis Lateralis
Branches from loop between C1-C2