Intermediate, Deep, Transversospinalis of Back

Question 1

Serratus Posterior Superior

Answer 1

Origin… C7-T3, nuchal ligament

Insertion… Superior aspect of ribs 2-5

Innervation… Anterior rami of upper thoracic nerves

Blood Supply… Posterior intercostal arteries

Action… Elevates ribs

Question 2

Serratus Posterior Inferior

Answer 2

Origin… T11-L2

Insertion… Inferior aspect of ribs 9-12

Innervation… Anterior rami of lower thoracic nerves

Blood Supply… Posterior intercostal arteries

Action… Depresses ribs

Question 3

Splenius Capitis

Answer 3

Origin… C7-T4, nuchal ligament

Insertion… Mastoid process, lateral 1/3 of superior nuchal line

Innervation… Posterior rami of middle cervical nerves

Blood Supply… Descending branch of occipital, deep cervical

Action… Bilaterally extends head; Unilaterally bends and rotates face towards same side

Question 4

Splenius Cervicis

Answer 4

Origin… T3-T6

Insertion… Transverse processes of C1-C3

Innervation… Posterior rami of lower cervical nerves

Blood Supply… Descending branch of occipital, deep cervical

Action… Bilaterally extends neck; Unilaterally bends and rotates neck towards same side

Question 5

Semispinalis

Answer 5

Origin… Transverse processes of C4-T12

Insertion… Spinous processes of cervical and thoracic vertebra (Capitis portion between superior and inferior nuchal lines)

Innervation… Posterior rami of spinal nerves

Blood Supply… Cervical portions: occipital, vertebral, deep cervical / Thoracic portions: dorsal branches of posterior intercostal arteries

Action… Extends head, neck, and thorax and rotates them to opposite side

Question 6

Erector Spinae

Answer 6

Origin… Posterior sacrum, iliac crest, sacro/supra-spinous ligaments, spinous processes of lower lumbar and sacrum

Insertion…
Iliocostalis: Angles of lower ribs, transverse processes
of cervical vertebrae
Longissimis: Between angles and tubercles of ribs,
transverse processes of cervical and
thoracic vertebrae, mastoid process
Spinalis: Spinous processes of upper thoracic and
middle cervical vertebrae

Innervation… Posterior rami of each region

Blood Supply…
Cervical: Occipital, deep cervical, and
vertebral arteries
Thoracic: Dorsal branches of posterior
intercostal, subcostal, and lumbar arteries
Sacral: Dorsal branches of lateral sacral arteries

Action… Extends and laterally bends vertebral column and head