Muscles of the Back and Neck
Splenius Blood Supply
supplied segmentally by deep cervical artery, posteriorly by intercostal arteries
Longissimus Blood Supply
supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.
Semispinalis Blood Supply
supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.
Spinalis Blood Supply
supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.
Iliocostalis Blood Supply
supplied segmentally by: deep cervical artery, posteriorly by intercostal arteries., subcostal arteries, and lumbar arteries
Iliocostalis Nerve Supply
Spinal nerves
Longissimus Nerve Supply
Spinal nerves
Semispinalis Nerve Supply
Spinal nerves
Spinalis Nerve Supply
Spinal nerves
Sternocleidomastoid Blood Supply
Sternocleidomastoid branch of the occipital artery
Quadratus Lumborum Nerve Supply
T12 and upper lumbar spinal nerves
Scalenes Nerve Supply
Cervical spinal nerves
Splenius Nerve Supply
Cervical spinal nerves
Scalenes Action
Elevate first two ribs; flex and rotate neck
Sternocleidomastoid Nerve Supply
Accessory nerve (cranial nerve XI) and branches of cervical spinal nerves C2 and C3
Splenius Action
Act as a group to extend or hyperextend head
Scalenes Blood Supply
Ascending vertical artery
Longissimus Action
Extend vertebral column and acting on one side bend it laterally; extends head and turns the face toward same side
Iliocostalis Action
Extend vertebral column, maintain erect posture
Spinalis Action
Extends vertebral column
Semispinalis Action
Extends vertebral column and head and rotates them to opposite side; acts synergistically with sternocleidomastoid muscles of opposite side
Quadratus Lumborum Action
Flexes vertebral column laterally when acting separately; when pair acts jointly lumbar spine is exteded and 12th rib is fixed; maintainsupright posture, assistsin forcedinspiration
Sternocleidomastoid Action
Prime moverof active head flexion; simultaneous contraction of both muscles causes neck flexion, generally against resistance
