MSK Exam I – Vertebral Column, ANS, Histology & Back Clinical Correlations

Vocabulary flashcards cover vertebral anatomy, spinal curves, joints, ligaments, pathologies, embryology, and autonomic terminology relevant to MSK Exam I.

Lordosis

Anteriorly convex spinal curve; normal in cervical and lumbar regions (secondary curve).

Kyphosis

Posteriorly convex spinal curve; normal in thoracic and sacral regions (primary curve).

Primary spinal curve

Kyphotic curvature present in the embryo (thoracic & sacral).

Secondary spinal curve

Lordotic curvature that develops post-natally in cervical and lumbar regions.

Atlas (C1)

First cervical vertebra; lacks a vertebral body, has anterior/posterior arches, lateral masses & large superior articular facets for skull.

Axis (C2)

Second cervical vertebra; characterized by the dens (odontoid process) projecting superiorly.

Dens (odontoid process)

Peg-like projection of C2 that articulates with the anterior arch of C1 at the median atlanto-axial joint.

Vertebra prominens

C7; has the longest cervical spinous process, usually non-bifid, palpable on neck flexion.

Uncinate process

Raised lateral lip on superior surface of cervical vertebral bodies that helps form uncovertebral joints.

Uncovertebral joint

Pseudo-synovial joint between uncinate process of a cervical vertebra and body of the vertebra above; alters cervical mechanics.

Costal facet (full)

Complete articular surface on thoracic vertebral body for a single rib (found on T1, T10–T12).

Costal demifacet

Half facet on thoracic vertebral body; superior & inferior demifacets from adjacent vertebrae articulate with one rib head.

Transverse costal facet

Articular surface on thoracic transverse process for rib tubercle (present T1–T10).

Intervertebral disc (IVD)

Fibrocartilaginous cushion between adjacent vertebral bodies composed of annulus fibrosus & nucleus pulposus.

Nucleus pulposus

Gelatinous core of an IVD; adult remnant of the notochord.

Pars interarticularis

Bony bridge between superior and inferior articular processes; common fracture site in spondylolysis.

Spondylolysis

Fracture (often stress) of the pars interarticularis, usually from repetitive lumbar hyperextension.

Spondylolisthesis

Anterior displacement of one vertebral body on another, often following bilateral pars fractures.

Hangman’s fracture

Traumatic bilateral pars fracture of C2 causing anterior displacement on C3 (hyperextension injury).

Perched facet

Inferior articular facet displaced anteriorly resting on superior facet of vertebra below (hyperflexion injury).

Hung facet

Inferior facet displaced completely anterior to superior facet below, often with spinal cord compromise.

Anterior longitudinal ligament (ALL)

Ligament running along anterior vertebral bodies; resists hyperextension.

Posterior longitudinal ligament (PLL)

Ligament within vertebral canal along posterior vertebral bodies; limits hyperflexion; above C2 called tectorial membrane.

Ligamentum flavum

Elastic ligament connecting laminae; forms part of facet joint capsule and assists recoil from flexion.

Interspinous ligament

Broad ligament connecting adjacent spinous processes (C7–sacrum); resists flexion.

Supraspinous ligament

Cord-like ligament on tips of spinous processes C7–sacrum; limits flexion; superiorly becomes ligamentum nuchae.

Cruciform ligament

Transverse ligament of atlas plus superior & inferior bands; stabilizes dens, limits C1/C2 flexion.

Alar ligaments

Pair attaching dens to medial occipital condyles; limit rotation of skull & C1.

Thoracic outlet syndrome

Neurovascular compression (often subclavian artery & brachial plexus) in root of neck, sometimes due to cervical rib.

Cervical rib

Extra rib from C7 transverse process; can compress subclavian artery/brachial plexus causing thoracic outlet syndrome.

Bowhunter’s syndrome

Rotational vertebral artery compression (often by uncovertebral osteophyte) causing vertebro-basilar insufficiency.

Cobb angle

Measurement on AP spine radiograph; >10° defines scoliosis, >25–30° warrants intervention, >50° severe.

Idiopathic scoliosis

Most common scoliosis type with unknown cause, often adolescent females.

Functional scoliosis

Lateral curve secondary to extra-spinal cause (e.g., leg-length discrepancy); resolves when cause corrected.

Neuromuscular scoliosis

Curve due to muscular or neurological disorders (e.g., cerebral palsy, DMD); progresses rapidly.

Congenital scoliosis

Curve caused by vertebral malformations such as hemivertebrae or block vertebrae.

Adult degenerative scoliosis

De novo lumbar curve from asymmetric IVD/facet degeneration in older adults, often obese.

Ankylosing spondylitis

HLA-B27-associated autoimmune spondylitis beginning at sacroiliac joints with ascending spinal fusion.

Rheumatoid atlantoaxial instability

RA destruction of transverse (±alar) ligament leads to excessive C1/C2 motion, potential brainstem compression.

Intervertebral foramen

Opening between pedicles transmitting spinal nerve and vessels; narrowed by IVD herniation or osteophytes.

Spinal cord termination

Conus medullaris ends ~L1/L2 IVD; lumbar puncture safely done at L3/4 or L4/5 into subarachnoid space.

Cauda equina

Bundle of dorsal & ventral roots below conus within lumbar cistern; displacement avoids injury during LP.

White ramus communicans

Myelinated pre-ganglionic sympathetic fibers entering sympathetic chain (T1–L2).

Gray ramus communicans

Unmyelinated post-ganglionic sympathetic fibers exiting sympathetic chain to join spinal nerves (all levels).

Splanchnic nerve

Preganglionic autonomic nerve (usually sympathetic) that bypasses chain ganglia to synapse in prevertebral ganglion.

Referred pain

Visceral (GVA) pain perceived in somatic dermatome due to convergence with GSA fibers at same spinal level.

EMT (epithelial-to-mesenchymal transition)

Process where epithelial cells become migratory mesenchyme; key in gastrulation and neural crest formation.

Notochord

Axial midline rod inducing neurulation & axial skeleton; persists as nucleus pulposus in adults.

Dens fracture Type II

Fracture at base of odontoid; poor healing, often requires surgical fixation.

Kyphoplasty

Procedure inflating vertebral body with balloon then filling with cement to correct osteoporotic wedge fractures.