Intermediate Intrinsic

Question 1

Erector Spinae - spinalis, longissimus, and iliocostalis

Answer 1

Spinalis: most medial, covers gutter, spine to spine
Longissimus: long thin fibers
Iliocostalis: ilium to ribs, most lateral

Innervation: dorsal rami of each region

Blood Supply: cervical portions - occipital artery, deep cervical artery, vertebral, thoracic portions - dorsal branches of posterior intercostal, subcostal, and lumbar arteries, sacral portions - dorsal branches of lateral sacral arteries

Action: keep spine erect, extends vertebral column and head, laterally bends vertebral column