Deep Muscles of the Back

Question 0

Erector Spinae (Iliocostalis)

Answer 0

Origin: Ilium and Ribs
Insertion: Ribs and Transverse Processes
Action: Extend Trunk and Vertebral Column
Nerve: Dorsal Rami of Spinal Nerves

Question 1

Splenius

Answer 1

Origin: Spines of T1-4
Insertion: Occipital and Temporal Bones (Capitis), Transverse Process of C2-3 (Cervical)
Action: Extend Neck and Head (rotate in a unilateral direction)
Nerve: Dorsal Rami of Spinal Nerves

Question 2

Erector Spinae (Longissimus)

Answer 2

Origin: Transverse Processes
Insertion: Transverse Processes
Action: Extend Trunk and Vertebral Column
Nerve: Dorsal Rami of Spinal Nerves

Question 3

Erector Spinae (Spinalis)

Answer 3

Origin: Spinous Processes
Insertion: Spinous Processes
Action: Extend Trunk and Vertebral Column
Nerve: Dorsal Rami of Spinal Nerves

Question 4

Transversospinalis

Answer 4

Three Types: Semispinalis, Multifudes, Rotatores

Origin: Transverse Process
Insert: Superior Spines (5-6, 3-4, 1-2 above respectively)
Action: Extend Trunk in Bilateral Action and Rotate Vertebral Column in Unilateral Action
Nerve: Dorsal Rami of Spinal Nerves