Muscles that move the head (anterolateral neck muscles)

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Muscles that move the head (anterolateral neck muscles)
2013-04-19 03:13:00

origin, insertion, and action
Show Answers:

  1. Sternocleidomastoid's origin
    Manubrium of sternum and medial portion of clavicle
  2. Sternocleidomastoid's insertion
    mastoid process of temporal bone and superior nuchal line of occipital bone
  3. sternocleidomastoid - action
    • flexes and laterally rotates the head;
    • simultaneous contraction of both muscles flexes neck, generally against resistance as when raising head when lying back;
    • acting alone, each muscle rotates head toward shoulder on opposite side and tilts or laterally flexes head of its own side
  4. semispinalis capitis - origin
    transverse processes of C7 - T12
  5. semispinalis capitis - insertion
    occipital bone (capitis) and spinous process of cervical (cervicis) and thoracic vertebrae T1-T4 (thoracis)
  6. semispinalis capitis - action
    • Extends vertebral column and head and rotates them to opposite side; 
    • act synergistically with sternocleidomastoid muscles of opposite side
  7. spenius capitis - origin
    • ligamentum nuchae, 
    • *spinous processes of vertebrae C7-T6
  8. splenius capitis - insertion
    • mastoid process of temporal bone and occipital bone (capitis); 
    • transverse processes of C2- C4 vertebrae (cervicis)
  9. splenius capitis - action
    extend of hyperextend head; when splenius muscles on one side are activated, head rotates and bends laterally toward same side