Anatomy of the Back

Question 1

Movements According to Spinal Region

Answer 1

Cervical ZP: facets are articulating in transverse plane to allow for lateral bending, rotation, E/F

Thoracic ZP: coronal plane to allow for rotation because limited by ribs

Lumbar ZP: sagittal plane to allow for E/F and lateral bending

Question 2

Whiplash Injury

Answer 2

4 Phases:

1. Head is extended back - limited by the headrest, but most of the damage is before your head hits the headrest
2. Forward seat recoil is occurring as your head is still moving backward
3. Head is at peak forward acceleration
4. Your seat belt and air big limit your forward motion, but this is where your head experiences the most damage from the entire ordeal from hyperflexion

Overall: potentially cause NP herniation and impingement of nerves + anterior longitudinal ligament tear

Question 3

Vertebral Body and IV Disc Development

Answer 3

Vertebral Body: from the sclerotome

NP: from notochord and sclerotome (type II collagen)

AP: from the sclerotome (type I collagen)

Question 4

Ribs Development

Answer 4

from sclerotome portion of paraxial mesoderm

Question 5

Transition Vertebrae

Answer 5

C7: extra rib can develop and cause thoracic outlet syndrome if impinges on the brachial plexus

L1: asymptomatic usually

Question 6

Bertolotti’s Syndrome

Answer 6

transitional 5th lumbar in utero causes sacralization, complete or partial fusion of the L5 and S1 portions from a larger transverse process, and limits movement in lumbosacral articulation causing back pain

Question 7

Sternum Development

Answer 7

6th week develops from lateral plate mesoderm

Sternal Cleft: incomplete fusion of L and R halves

Pectus Excavation: sunken chest from growth of sternum, 4th, and 5th ribs in utero from increased pressure and increased traction of diaphragm

Pectus Carinatum: pigeon chest; overgrowth of cartilage; congenital, surgical (like open heart), or during puberty

Question 8

Skeletal Muscle Myotome Development

Answer 8

Extremities: from lateral plate mesoderm
Trunk: tensons from sclerotome

Myotome: splits into two

1. Epimere: intrinsic muscles of back and neck (innervated by dorsal rami)
2. Hypomere: all other post cranial muscles (innervated by ventral rami)