Vertebral Column I

Question 1

how many vertebrae and intervertebral discs are there?

Answer 1

24 mobile vertebrae, 23 intervertebral discs (no disc between C1+2 bc C1 has no intervertebral disc)

Question 2

functions of the vertebral column? and how do these functions vary in different roles?

Answer 2

protection, weight-bearing/force transmission, mobility. different roles: cervical carries head so doesn’t have large weight bearing role compared to what’s required in the lumbar region, cervical is more moblie to move special sense organs around and to see environment, as you progress down the VC you have greater weight bearing role

Question 3

describe the vertebral column motion segment

Answer 3

the superior vertebra moves on the inferior vertebrae

Question 4

name the movements of the vertebral motion segments

Answer 4

3 rotations: coronal plane rotation L and R, sagittal plane tilt (rotates) anterior/posterior, vertical axis axial rotation
3 translations: coronal plane translation L and R, sagittal plane translation anterior/posterior, vertical axis translation extract/compress

Question 5

describe features of a cervical vertebrae.

v body size? foramen? spinous process? articular facet? any other features?

Answer 5

small v body, lateral/unconvertebral lips on the body, large vertebral foramen, transverse foramen for vertebral artery, anterior and posterior tubercles, bifid spinous process, articular facets 45 degrees to the transverse plane

Question 6

describe features of a thoracic vertebrae

v body size? foramen? spinous process? articular facet? any other features?

Answer 6

medium v body, wedge shape- anterior v body height < posterior, small round vertebral body, articular demifacets on body articulate w/ribs, articular facets on transverse process for ribs, long downward pointing spinous process, articular facet almost in coronal plane

Question 7

describe features of a lumbar vertebrae

v body size? foramen? spinous process? articular facet? any other features?

Answer 7

large v body for weight bearing, flat superior/inferior vertebral body, small triangular vertebral body, thick blunt spinous process, mammillary processes, articular facets in the sagittal plane

Question 8

why does the vertebral body have both horizontal and vertical struts

Answer 8

vertical struts are thicker for weight bearing but are supported by horizontal struts

Question 9

what is nucleus pulposus?

Answer 9

up to 90% water (incompressible) but is thickened by proteoglycans and collagen

Question 10

what is annulus fibrosus?

Answer 10

10-20 concentric layers, all fibres in 1 layer = same orientation and opposite to adjacent layer, collagen I fibres to resist tension and encircles NP around and up and over

Question 11

describe the role of intervertebral disc in weight bearing

Answer 11

A. NP= incompressible, vertical compression of the NP decreases vertical height, expands radially and exerts pressure on the annulus fibres
B. annular fibres resist tension and exert pressure back onto NP
C. NP and AF share the pressure and the pressure is exerted onto the vertebral endplates
D. transmits load to inferior vertebrae

Question 12

how could dysfunction in the intervertebral disc occur during weight bearing

Answer 12

dysfunction occurs when the NP dries out and has less volume OR stretching/tearing of the AF occurs

Question 13

describe the role of the intervertebral disc in facilitating movement

Answer 13

by separating the 2 surfaces by an intervertebral disc it maintains the ideal flat weight bearing component and distributing the force to decrease stress and so that the superior vertebrae can undergo angular rocking tilt before impacting the inferior vertebrae (the greater amount of seperation = greater amount of movement)

Question 14

what are the posterior elements and what are their functions

Answer 14

lamina, articular processes, spinous process, transverse processes. functions: muscle and ligament attachments, provide stability, guide movement

Question 15

what is the role of the zygapophyseal joints in resisting movement

Answer 15

inferior articular processes hook onto the superior articular processes of the vertebrae below: depending on the orientation of the articular facets or the height of the superior articular processes they may resist forward sliding and/or rotation of the upper vertebrae

Question 16

in relation to the zygapophyseal joint, what do the superior articular facets aligned in the coronal plane resist?

Answer 16

resists anterior translation of the superior vertebrae even more so the more vertical they are (block flexion)

Question 17

in relation to the zygapophyseal joint, what do the superior articular facets aligned in the sagittal plane resist?

Answer 17

resists axial rotation of the superior vertebrae (allows F-E, block rotation)

Question 18

in the cervical region, what movements does the zygapophyseal joint allow?

Answer 18

all movements

Question 19

in the thoracic region, what movements does the zygapophyseal joint allow?

Answer 19

allows axial rotation and lateral flexion

Question 20

in the lumbar region, what movements does the zygapophyseal joint allow?

Answer 20

flexion - extension

Question 21

why are the posterior elements not good at weight bearing and what is the possible injury

Answer 21

activities (e.g. gymnastics, ballet) where you land in extension combined with rotation (particularly load one side) instead of transferring force through your anterior elements (that are already efficient at it), you are transferring force from your inferior articular process down into your lamina between the superior and inferior articular process = par interarticularis
cause a par interarticularis fracture

Question 22

what region is most exposed to pars interarticularis and why?

Answer 22

LUMBAR bc you are already in lordosis (partly extended in some degree) and posterior tilt (L4 and L5 main area of pars interarticularis

Question 23

what is the role of the intervertebral disc in resisting movement?

Answer 23

collagen fibres in the annulus fibrosus resist tension

Question 24

what is the anterior longitudinal ligament connected to?

Answer 24

connected to anterior vertebral bodies and anterior intervertebral discs

Question 25

what is the posterior longitudinal ligament connected to?

Answer 25

connected to posterior vertebral bodies and intervertebral discs (on the anterior aspects of the vertebral canal)

Question 26

where is the ligamentum flavum located?

Answer 26

between adjacent lamina & forms the posterior wall of the vertebral canal and anterior capsule of z joints

Question 27

where is the interspinous ligament located?

Answer 27

between adjacent spinous process

Question 28

where is the supraspinous ligament located?

Answer 28

attaches posterior aspects of spinous processes

Question 29

what ligaments provide resistance to flexion?

Answer 29

PLL, LF, ISL, SSL

Question 30

what ligaments provide resistance to extension?

Answer 30

ALL (anterior longitudal ligament)