Crucial muscles involved in swallowing and speech
Control positions of the larynx and hyoid bone
Key anatomical structures:
Hyoid Bone: Provides a stable base for tongue movement
Thyroid Cartilage: Part of the larynx
Thyroid Gland: Endocrine gland located in the anterior neck
Suprahyoid Muscles: Muscles above the hyoid bone, elevate hyoid and larynx during swallowing
Inferior Muscles: Muscles below the hyoid bone, depress hyoid and control larynx position
Digastric Muscle
Consists of anterior and posterior bellies, elevates hyoid and larynx, depresses mandible
Stylohyoid Muscle
Moves hyoid bone posteriorly, elevates the larynx
Mylohyoid Muscle
Elevates hyoid bone, presses tongue against the roof of the mouth
Geniohyoid Muscle
Raises hyoid bone, depresses mandible
Omohyoid Muscle
Composed of superior and inferior bellies, depresses hyoid bone
Thyrohyoid Muscle
Elevates the thyroid cartilage of the larynx
Sternothyroid Muscle
Depresses the thyroid cartilage, aids in voice tone control
Neck muscles essential for head stability and movement
Sternocleidomastoid
Major muscle responsible for lateral flexion and rotation; divides the neck into triangles
Table of Head Movements: Overview of various muscles involved in head movements
Sternocleidomastoid
Functions:
Unilateral: Rotates head to opposite side
Bilateral: Flexes the head
Origin: Sternum and clavicle
Insertion: Temporal bone and occipital bone
Semispinalis Capitis
Functions: Extends and laterally flexes the head, rotates
Origin: Transverse processes of cervical and thoracic vertebrae
Insertion: Occipital bone
Splenius Capitis
Functions: Rotates and extends the head
Origin: Spinous processes of cervical and thoracic vertebrae
Insertion: Temporal bone and occipital bone
Longissimus Capitis
Functions: Rotates and extends the head
Origin: Transverse processes of cervical and thoracic vertebrae
Insertion: Temporal bone
Functions: Stabilization and movement of the vertebral column
Splenius Muscles
Originate at midline, insert laterally and superiorly
Functions: Extension, lateral flexion, and rotation of head
Erector Spinae Group
Main extensor of the vertebral column
Subgroups:
Iliocostalis: Cervicis, thoracis, lumborum
Longissimus: Capitis, cervicis, thoracis
Spinalis: Capitis, cervicis, thoracis
Transversospinales Muscles
Stabilize the vertebral column through connections between vertebrae
Include semispinalis muscles related to their regions
Multifidus Muscle
Located in the lumbar region, aids in vertebral column extension and lateral flexion
Segmental Muscle Group
Includes interspinales and intertransversarii muscles, contributes to vertebral stability
Scalene Muscles
Function in head movement and assist in breathing
Include anterior, middle, and posterior scalene muscles
Fascicles: Bundles of muscle fibers that work together for movement.
Flexion: Bending of a joint to decrease the angle between body parts (e.g., neck bending forward).
Extension: Straightening a joint to increase the angle (e.g., tilting the head backward).