Back Anatomy and Movement

vertebral column

body

rounded weight-bearing block of bone that makes up the front of the vertebra

vertebral foramen

the central opening enclosed by the vertebral arch; stacked together to form the vertebral canal that houses the spinal cord

pedicle

the short bony strut connecting the vertebral body to the lamina on each side

lamina

the flat bony plate that completes the vertebral arch running from the pedicle to the spinous process

vertebral arch

the bony ring formed by the pedicels and laminae together enclosing the vertebral foramen

spinous process

the single posterior projection formed where 2 laminae meet; often palpable through the skin

transverse process

the paired projections extending laterally from each pedicle-lamina junction

articular processes (zygapophyses)

the paired superior and inferior projections that form the facet joints linking one vertebra to the next

annulus fibrosus

the tough fibrous outer ring of the intervertebral disc

nucleus pulposus

the soft gel-like center of the disc that cushions comprehensive load

intervertebral foramen

the opening between 2 adjacent vertebrae where a spinal nerve exists the vertebral column

cervical

the neck; 7 vertebrae (no ribs)

thoracic

where each vertebra has a pair of ribs attached; 12 vertebrae

lumbar

below the ribcage; 5 vertebrae and is usually the largest and sturdiest

sacral

within the pelvis; 5 vertebrae fused together into the sacrum

scapular spine

the ridge running diagonally across the posterior surface of the scapula

acromion

the bony point at the lateral end of the scapular spine, forming the tip of the shoulder

glenois fossa

the shallow socket on the scapula that receives the head of the humerus

humeral head

the rounded proximal end of the humerus that sits in the glenoid fossa

greater/lesser tubercle

the 2 bony prominences on the proximal humerus, lateral and anterior to the head

intertubercular groove

the groove running between the greater and lesser tubercles

latissimus dorsi

• origin: thoracolumbar fascia; iliac crest; T6 to T12 spinous processes

• insertion: intertubercular groove of the humerus

• action: adducts, extends, and medially rotates the humerus at the shoulder

trapezius

• origin: external occipital protuberance; ligamentum nuchae; C7 to T12 spinous processes

• insertion: scapular spine; acromion; lateral third of the clavicle

• action: elevates and retracts the scapula and rotates it to help elevate the shoulder joint

rhomboid major

• origin: T2 to T5 spinous processes

• insertion: medial border of the scapula

• action: retracts the scapula

rhomboid minor

• origin: C7 to T1 spinous processes

• insertion: medial border of the scapula

• action: retracts the scapula

sagittal plane

flexion and extension happens in the……

frontal (coronal) plane

abduction and adduction happens in the……

transverse plane

rotation happens in the…….

medial rotation

turning the front limb toward the midline

lateral rotation

turning the front of a limb away from the midline

elevation

raising a structure as with the scapula

depression

lowering a structure as with the scapula

retraction

pulling a structure toward the midline as with the scapula and toward the spine

protraction

pulling a structure away from the midline as with the scapula and away from the spine