Functional Anatomy of the Spine

Question 1

functions of the vertebral column

Answer 1

support

posture

protection

locomotion

Question 2

components of the vertebral column

Answer 2

vertebrae plus intervertebral discs - 75% vertebrae, 25% discs

separate elements for flexibility/mobility/shock absorption

ligaments and muscles

Question 3

What are the divisions of the vertebral column?

Answer 3

cervical 7 - all mammals have these

thoracic 12 - defined by the ribs

lumbar 5

sacral 5

coccygeal 4

Question 4

Why is there a curvature in the vertebral column?

Answer 4

acts as a spring, the “S” shape gives a lot more shock absorption

kyphosis - convex posteriorly

lordosis - convex anteriorly

scoliosis - lateral curvature

Question 5

lordosis vs. kyphosis

Answer 5

lordosis - when curvature is in the front (primary - thoracic and sacral)

kyphosis - when curvature is in the back (secondary - cervical and lumbar)

Question 6

What is the common finding in Scheuermann’s disease?

Answer 6

abnormal kyphosis - common in adolescents

Question 7

What are the common causes in abnormal lordosis?

Answer 7

obesity

pregnancy

achondroplasia

spondylolysthesis

Question 8

What are the different parts of a vertebral segment? What are their functions?

Answer 8

body or centrum - weight support, intervertebral discs are placed between the bodies

vertebral arch - pedicle, lamina, vertebral foramen for spinal cord

transverse process, spinous porcess - attachment of muscles

superior and inferior articular facets - articulation with vertebrae above and below, shape and oridentation determines kinds of movements allowed

intervertebral foramen - for passage of spinal nerves

Question 9

What are the parts of the vertebral arch?

Answer 9

lamina

pedicle

spinous process

articular process

transverse process

vertebral foramen

Question 10

What are the defining features of the cervical vertebra?

Answer 10

has a transverse foramen

Question 11

What are the defining features of the thoracic vertebra?

Answer 11

rib articular facets

Question 12

What are the defining features of the lumbar vertebra?

Answer 12

large bodies

Question 13

What is the role of ligaments in the spine?

Answer 13

prevents excessive/unwanted movement between the vertebrae in order to protect joints and nerves

instability of the vertebral column can compress and damage the spinal ord or spinal nerves leading to pain, paresthesia, muscle weakness, or paralysis

Question 14

What are the ligaments in the spine and what are their functions?

Answer 14

anterior lingitudinal - prevents hyperextension (whiplash)

posterior longitudinal - prevents hyperflexion

ligamentum flavum - between laminae

suprspinous - along spines, ligmentum nuchae

interspinous - unites two adjacent spines

Question 15

How does the three column model of Dennis reflect the stability of the vertebral column?

Answer 15

spinal stability is dependent on at least two intact columns

whent two of the three columns are distrupted, abnormal segmental motion is allowed

this leads to instability, and the spinal nerves and spinal cord are at risk of injury as a result

Question 16

What feature of the spinal chord is a common cause of pain?

Answer 16

facet joints are common sites of pain

osteophytes here are implicated

Question 17

What determines the range of motion in a particular segment of the vertebral column?

Answer 17

compressibility and elasticity of the discs

shape and orientation of the articular facets

condition of back muscles and ligaments

rib attachment

Question 18

Describe the mobility of the cervical, thoracic, and lumber regions of the spine.

Answer 18

cervica is the most mobile - all movements allowed

thoracic region - flexion-extension is restricted by the ribs

lumber - very little rotation due to the mediolaterally facing articular facets

Question 19

spondylolisthesis

Answer 19

anterior or posterior displacement (slippage) of one vertebrae relative to another

the spinal cord and nerves can be compromised

Question 20

spondylolysis

Answer 20

a defect (separation) in the vertebral pars interarticularis, usually in the lower lumbar vertebrae, particularly L5

see the “Scotty dog” sign in x-rays

Question 21

sciatica

Answer 21

radiating pain in the L4-S2 dermatones

Question 22

What is the role of the intervertebral disc?

Answer 22

acts as a shock absorber and mediates movement between vertebral bodies

Question 23

What makes up the intervertebral disc?

Answer 23

fibrocartilage annulus

fibrogelatinous nucleus pulposus which is a remnant of the embryonic notochord

Question 24

extrensic vs. intrinsic muscles of the back

Answer 24

extrinsic - develop from hypomere, anterior (ventral) rami innervation, attache to limbs (except serratus posterior), and function is to move limbs

intrinsic - develop from epimere, posterior (dorsal) rami innervation, attach to vertebral column and ribs, function is to move vertebral column

Question 25

epaxial muscles

Answer 25

muscles that develop from the epimere form intrinsic muscles of the vertebral column - mainly extensors and rotators ex. splenius, erector spinae, transversospinalis

Question 26

hypaxial muscles

Answer 26

muscles that develop from the hypomere extrnsic to the vertebral column may not attach to parts of vertebrae but form body wall or limb muscles ex. flexor muscles of the vertebral column, rects abdominis, intercostals, abdominal obliques, rhomboids, levator scapulae, latissimus dorsi

Question 27

function of the trapezius

Answer 27

rotates and retracts scapula innervated by the cranial nerve XI

Question 28

function of the latissimus dorsi

Answer 28

extends and adducts the arm

Question 29

function of the levator scapulae

Answer 29

elevates the scapula

Question 30

function of the rhomboids

Answer 30

retract scapula

Question 31

What are the movements of the vertebral column?

Answer 31

extension - flexion lateral bending rotation

Question 32

What determines the range and types of motion of the vertebral column?

Answer 32

compressibility and elasticity of the discs shape of articular facets conditions of back muscles and ligaments rib attachment

Question 33

What is the range of motion in each of the regions of the vertebral column?

Answer 33

cervical most mobile - all movements thoracic region - flexibility is restricted by ribs lumbar - very little rotation

Question 34

function of the splenius muscles (capitis and cervicis)

Answer 34

ipsilateral rotation lateral bending extension

Question 35

What are the functions of the erector spinae?

Answer 35

lateral bending extension

Question 36

What are the different subcategories of the erector spinae?

Answer 36

spinalis longissimus iliocostalis

Question 37

What are the components of the transversospinalis and what is its function?

Answer 37

semispinalis, rotatores, and multifidus function - contralateral rotation and extension