Intermediate Layer (Erector Spinae)

Question 1

Iliocostalis (3 parts)

Answer 1

O: broad tendon that attaches to iliac crest, sacrum, sacroiliac ligaments, and sacral and inferior lumbar spinous process
I: -Lumborum- iliac crest and attaches into the angles of inferior 6 ribs
-Thoracis- arises from the 6 lower ribs and attaches to the 6 upper ribs
-Cervicis- arises from 6 upper ribs and attaches to transverse process of C4-C6
A: extension of vertebral column
N: dorsal primary rami

Question 2

Longissimus (3 parts)

Answer 2

O: broad tendon that attaches to iliac crest, sacrum, sacroiliac ligaments, and sacral and inferior lumbar spinous process
I: -Thoracis- arises from lower lumbar spinous processes and sacrum and attaches to lower 9 ribs and associated transverse processes
-Cervisis- arises from transverse process of T1-T6 and attaches to transverse processes of C2-C6
-Capitis- arises from lower 4 cervical vertebrae and attach to the mastoid process of temporal bone
A: extension of vertebral column
N: dorsal primary rami

Question 3

Spinalis

Answer 3

O: spinous process T11-L2
I: spinous process of upper 4to 8 thoracic vertebrae
A: extension of spinal column
N: dorsal primary rami