Question | Answer |
digastric | origin: mastoid region of temporal bone and inferior surface of mandible |
digastric | insertion: hyoid bone |
digastric | has two bellies |
digastric | action: depresses mandible and/or elevates larynx |
sternohyoid | origin: clavicle and sternum |
sternohyoid | insertion: hyoid bone |
sternohyoid | thin muscle attaching sternum to the hyoid |
sternohyoid | action: depresses hyoid bone and larynx |
stylohyoid | origin: styloid process of temporal bone |
stylohyoid | insertion: hyoid bone |
stylohyoid | forms a muscular connection between the hyoid bone and the styloid process of the skull |
stylohyoid | action: elevates larynx |
sternocleidomastoid | origin: superior margins of sternum and clavicle |
sternocleidomastoid | insertion: mastoid region of skull |
sternocleidomastoid | extends from the clavicle and the sternum to the mastoid region of the skull |
sternocleidomastoid | action: both sides together flex the neck; one side alone bends head towards shoulder and turns face to opposite side |
spinalis group | origin: spinous processes and transverse processes of cervical, thoracic, and upper lumbar vertebrae |
spinalis group | insertion: base of skull and spinous processes of cervical, thoracic and upper thoracic vertebrae |
spinalis group | action: the two sides act together to extend vertebral column; either alone extends neck and laterally flexes head or rotates vertebral column to that side |
longissimus group | origin: processes of lower cervical, thoracic, and upper lumbar vertebrae |
longissimus group | insertion: mastoid process of temporal bone, transverse process of cervical vertebrae, and inferior surfaces of ribs |
longissimus group | action: the two sides act together to extend vertebral column; either alone rotates and laterally flexes head or vertebral column to that side |
iliocostalis group | origin: superior borders of ribs and iliac crest |
iliocostalis group | insertion: transverse processes of cervical vertebrae and inferior surfaces of ribs |
iliocostalis group | action: extends vertebral column or moves laterally to that side; moves ribs |
quadratus lumborum | origin: iliac crest |
quadratus lumborum | insertion: last rib and transverse processes of lumber vertebrae |
quadratus lumborum | action: together they depress ribs, flex vertebral column; one side acting alone produces lateral flexion |