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Flashcards in Exam II: Back I Deck (39):

Vertebral Column Composition

Parts: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral, ~4 fused coccygeal

Movements: flexion (bend forwards), extension (bend backwards), rotation, side-bending

Support: muscles, body weight, head, transmit forces, and upper limbs
Protection: spinal cord and portions of the spinal nerves
Movement: move upper limbs and ribs, maintains posture, and bending over


Curvatures of the Vertebral Column

Adult: composed of cervical, thoracic, lumbar, sacral/coccygeal curvatures
Primary curvature- concave anteriorly (made by thoracic and sacral/coccygeal)
Secondary curvature- concave posteriorly (made by cervical and lumbar); important for standing upright; curvatures develop to balance the line of gravity from skull to pelvis

Fetal: completely concave anteriorly
Primary curvatures develop in utero
As we grow and walk we form secondary curvature


Features of a Typical Vertebrae

Vertebral arch: lamina meet to form roof of the vertebral arch
Vertebral body, superior and inferior articular processes, pedicles, lamina, spinous processes
Synovial joints between articular processes
Has 4 synovial joints (2 above and 2 below)
Has 2 symphyses (1 above and 1 below) with intervertebral discs


Regional Differences of Vertebrae

Cervical – smaller bones support the weight of the head and are flexible to allow a wide range of head movement; also, the axis is the only vertebra with no vertebral body

Thoracic – larger bones than in the cervical region; more rigid to provide a framework for the ribcage and the torso in order to protect the inner organs

Lumbar – largest bones in the spine; support most of the weight of the upper body and allow for bending, twisting and hip flexion


Features of Cervical Vertebrae

1. Body: small and square; wider side-to-side than anterior- posterior
2. Vertebral Foramen: large and triangular (for cervical enlargment of the spinal cord
3. Transverse Process: have anterior and posterior tubercles (at C6 they are large and termed "carotid tubercles"; have transverse foramina (for vertebral arteries, veins and sympathetic plexus; vertebral artery DOES NOT traverse the foramen at C7)
4. Articular Process: superior facets are directed superiorly and posterior; nearly horizontal
5. Spinous Process: relatively short and bifid (especially C3 - C5); the spines of C6 and 7 are longer (C7 is vertebra prominens)
6. Articular facets are sloped anterior to posterior


Features of the Thoracic Vertebrae

Demifacets- ribs
Circular vertebral canal
Superior and inferior facets are more vertically oriented

1. Body: heart-shaped and has costal facets
2. Vertebrae Foramen: round and smaller
3. Transverse Process/Costal facets: large for articulation with ribs; TV1 - 10 have costal facets
4. Articular Process: superior facets are directed posterior and lateral
5. Spinous Process: long and projected posterior and inferior


Features of the Lumbar Vertebrae

Lack facets for ribs
Mamillary process on superior articular facet that attaches to muscle

1. Body: large and broad; cylindrical
2. Vertebral Foramen: large (for lumbar enlargement; but smaller than cervical) and triangular
3. Transverse Process: long and slender; include accessory process
4. Articular Process: superior facets are directed posterior and medial; includes mamillary process
5. Spinous Process: short and sturdy


Features of Sacrum and Coccyx

Articulates with pelvis
Sacral foramina: where sacral nerve rami (1-4) exit the vertebral column


Important Landmarks of the Vertebral Column

Spinous process of C7: vertebra prominens; first process you feel on your neck
Spinous process of T3: scapular spine
Spinous process of T7: inferior scapular angle
Spinous process of T12: twelfth rib
Spinous process of L4: iliac crest


Intervertebral Discs

Symphyses between vertebral bodies
Anulus fibrosus- outside fibrous ring and allows for transmission of forces
Nucleus pulposus- gelatinous inside core; thinner posteriorly than anteriorly; absorbs compression
Fibrous cartilage present here


Zygapophysial joints

Plane synovial
Between articular facets
Pars interarticularis: area between superior and inferior articular facets

Cervical Vertebrae: sloped anterior to posterior to allow you to flex and extend your neck
Thoracic Vertebrae: facilitate rotation; vertical ZP
Lumbar Vertebrae: very curved to limit movement, but still do a good amount of flexion and extension; wrapped ZP


Cervical Vertebrae Form Uncovertebral Joints

Aka: Joints of Luchska
Between cervical bodies C3-C6
Synovial joints
upper surfaces of cervical vertebrae are elevated into crests = uncinated processes

Uncovertebral Joints: common site for spur formation, and degeneration may impinge spinal nerves
Spurs/chunks of bone can come out, and if large enough they can impinge the nerves and vertebral artery
Spurs are due to loss of cartilage and then the bone overgrows to compensate and can cause problems with ligaments/ nerves


What goes between the intervertebral foramen?

root of each spinal nerve, dorsal root ganglion, the spinal artery of the segmental artery, communicating veins between the internal and external plexuses, recurrent meningeal (sinu-vertebral) nerves, and transforaminal ligaments
Overgrowth in elderly vertebrae can cause pinching of the nerve within the intervertebral foramen


5 Ligaments that Reinforce the Joints

1. Anterior longitundinal

2. Posterior longitundinal

3. Ligamenta flava

4. Interspinous

5. Supraspinous


Normal vs. Abnormal Curvatures

Kyphosis /hunch back- elderly and bad posture
Lordosis- pot bellies, pregnant women
Scoliosis – during development can be congenital or due to activity; lateral curvature of the spine


Features of Atlas and Axis

Atlas: C1; 2 lateral masses connecting to occipital condyle, anterior and posterior arches, and transverse ligament
Axis: C2; anterior and posterior arches and dens (nodule) from vertebral body of C1, but fused with the axis to form the dens during development
Dens is held by transverse ligament of the atlas
C1 lack a vertebral body
No intervertebral disc between C1 and C2
Atlanto axial joint: “no" joint
Atlanto-occipital joint: "yes" joint
Alar ligament on dens is bilateral and prevents excessive rotation


Ligamentum Nuchae

Ligamentum Nuchae: above the supraspinous ligament (and runs into it) from skull (external occipital protuberance to foramen magnum) to C7; triangular, sheet like structure in the median sagittal plane

Resists separation of laminae in flexion and assists in extension back to anatomical position; resists flexion and facilitates returning the head to anatomical position
Lengthens spinous processes

Posterior longitudinal ligament becomes the tectorial membrane, which inserts into the foramen magnum to reinforce your altanto- occipital joint


Alar Ligaments

Limit rotation of head
Atlanto-occipital joint- synovial condyloid “YES” between occipital and C1
Atlanto-axial joint- synovial gliding “NO” between C1 and C2
Cruciform: forms a cross to reinforce the altano-axial joint
Alar goes from dens to formamen magnum; “check ligaments” so you don’t rotate your head too much



Herniations of the annulus fibrosis ; nucleus pulposus can herniate through the annulus fibrosis; when it pops through it goes into the vertebral canal and impinge the spinal nerves
Posterior longitudinal ligament tries to prevent this but can’t always


Sacroiliac and Iliolumbar Ligaments

Sacrum to pelvic bone; sacroiliac
Lumbar to iliac crest: iliolumbar


Hangman's Fracture

Basic Mechanism: violent hyperextension, which can be followed by rebound flexion or abrupt deceleration via hanging, MVA (motor vehicle accident)
Compression force can fracture C1&C3
Fracture of C2 pars interarticularis



Spondylolysis- fracture of pars interarticularis “collar”
shaped like a dog and can have a dog collar or not
Dog's eye: pedicle that connects vertebral bodies to the transverse arch
Dog collar= fracture in that spot (darker)
mostly occurs in lumbar spine/L5
most likely complication due to spondylolysis is spondyolisthesis (vertebrae slippage)



Vertebra slips forward upon its inferior counterpart without a pars interarticularis fracture due to an abnormal anatomy of the facet joints from a degenerative change, but usually the most likely cause is spondylyolysis fracture of pars interarticularis
ex. Vertebral body is sitting more anteriorly


Dermatomes of the Back

Dermatomes innervated by posterior rami of spinal nerves
Most of head= C2, neck=C3, and lower neck/upper area between shoulders= C4
Thoracic: T2-T12
Lumbar: L1-L5
Sacral: S1-S5/Coccyx
*These are the cutaneous branches representing the dermatomes


Superficial Muscles

Separated from deep muscles and innervated by anterior rami and control the upper limbs


Superficial Muscles- 1st Layer

Origin- superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous processes of C7 to T12

Insertion- acromion process, spine of scapula, and lateral 1/3 of clavicle

Action- abduction of humerus above horizontal by allowing for rotation of scapula; elevate, retract/adduct, and depress scapula via upper, middle, and lower fibers respectively

Innervation- accessory nerve/cranial 11; proprioception C3 and C4

Blood Supply: superficial branch of the transverse cervical artery and branch of thyrocervical trunk


Superficial Muscles- 1st Layer
Latissimus Dorsi

Latissimus Dorsi:
Origin- spinous process of T7 to T12and sacrum, iliac crest, ribs 10 to 12
Insertion-anterior portion of humerous and intubercular sulcus/ floor of intertubercular sulcus/groove of humerus
Action- extends, adducts, and medially rotates the arm
Innervation- thoracodorsal nerve C6 to C8
Blood Supply: thoracodorsal artery (major source) and dorsal branches of posterior intercostal and lumbar arteries


Superficial Muscles- 2nd Layer
Rhomboid Major

Rhomboid Major
Origin- spinous processes of T2-T5
Insertion- medial border of the scapula between spine and inferior angle
Action- retracts/adducts scapula towards the midline and elevates scapula
Innervation- dorsal scapular nerve (C4, C5)
Blood Supply: deep branch of the transverse cervical artery


Superficial Muscles- 2nd Layer
Rhomboid Minor

Rhomboid Minor
Origin- lower portion of ligamentum nuchae, spinous processes of C7-T1
Insertion- medial horn/border of the scapula at spine of scapula
Action- retracts/adducts the scapula towards the midline and elevates the scapula
Innervation- dorsal scapular nerve (C4, C5)
Blood Supply: deep branch of the transverse cervical artery


Superficial Muscles- 2nd Layer
Levator Scapulae

Levator Scapulae
Origin- Transverse processes of C1-C4
Insertion- upper portion medial border of scapula/superior angle of the scapula
Action- elevate the scapula
Innervation- C3 to C4 and dorsal scapular nerve (C4, C5)
Blood Supply: deep branch of the transverse cervical artery


Common Variations of the Transverse/Superficial Cervical Artery

1. thyrocervical trunk will give off to transverse cervical artery (TCA), and 38% of the time will branch off into superficical or deep (not always deep)
2. 25% of the time the subclavian artery will branch off to descending scapular artery


Intermediate Muscles: Serratus Posterior Superior

Serratus posterior superior:
Origin- lower portion of ligamentum nuchae, spinous processes of C7-T3, and supraspinous ligaments
Insertion- upper border of ribs 2-5 just lateral to their angles
Action- elevate the ribs 2-5 and assist in inspiration
Innervation- anterior rami of upper thoracic nerves T2-5


Intermediate Muscles: Serratus Posterior Inferior

Serratus posterior inferior:
Origin- Spinous processes of T11-L3 and supraspinous ligament
Insertion- lower border of ribs 9-12 just lateral to their angles
Action- depress ribs 9-12 and may prevent lower ribs from being elevated when the diaphragm contracts because they are oriented upwards; assist in respiration
Innervation- anterior rami of lower thoracic nerves T9-12


Superficial Triangles

Triangle of Auscultation: boundaries superiorly and medially, by the inferior portion of the trapezius, inferiorly, by the latissimus dorsi, laterally, by the medial border of the scapula and rhomboid muscle

Lumbar Triangle: inferior lumbar hernia (Petit’s Hernia); composed of the iliac crest inferiorly and the margins of two muscles – latissimus dorsi (posteriorly) and external abdominal oblique (anteriorly). The floor of the inferior lumbar triangle is the internal abdominal oblique muscle. The fact that herniations occasionally occur here is of clinical importance


Anterior Longitudinal Ligament

prevents hyperextension; attached to base of the skull and extends inferiorly to the anterior surface of the sacrum; attaches to anterior side of vertebral bodies and intervertebral discs


Posterior Longitudinal Ligament

prevents hyperflexion; on posterior surfaces of vertebral bodies and lines the anterior surfaces of the vertebral canal
connects C2 to intracranial base of skull= tectorial membrane


Ligamentum flava

between laminae
bilateral and pass between laminae
thin and broad with elastic tissue
form posterior surface of vertebral canal
resists separation of laminae during flexion


Supraspinous Ligament

resists separation of the spinous processes during flexion and extension; connects and passes along the tips of the vertebral spinous process from vertebra C7 to sacrum


Interspinous Ligament

pass between adjacent vertebral spinous processes
attach from base to the apex of each spinous process
blends with supraspinous ligament posteriorly and ligamentum flava anteriorly on each side