LUMBAR SPINE - ARTHROLOGY Flashcards

(43 cards)

1
Q

The vertebral column

A

Median and dorsal 33 vertebrae

🔸Cervical- 7

🔸Thoracic- 12. 🔸(24 free vertebrae)

🔸Lumbar-5

Sacral- 5 (fused together to form sacrum)

Coccygeal- 4
(Fused together to form rudimentary tail)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Spinal curvatures

A

Spine curves when all parts are put together

Primary and secondary curvature is which gives us our normal posture

Cervical curvature – secondary curvature
thoracic curvature – primary curvature
Lumber curvature – secondary temperature
Sacral/coccygeal curvature – primary curvature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Primary Curvature

A

Thoracic and sacral region primarily for protection there is little or no movement

Thoracic region help to form part of the rib cage- protects lungs

Sacral region help to form part of the pelvic ring – protects pelvic viscera

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Secondary curvature

A

Cervical and lumbar region created by increased anterior thickness in intervertebral discs

  • more movements are more likely to be affected by degenerative changes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

2 joints at a segment level L2–3

A

2 joints

Anteriorly :
(Invertebral body +disc)
2nd cartilagineous or Symphyseal joint (mid line of body)

Posteriorly:
Synovial plane or Zygoapophyseal or Facet joint
Superior and inferior facets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Synovial joint

A

Majority of joints in body

Articular surface = hyaline cartilage

Joint cavity, fibrous capsule, synovial membrane, synovial fluid

Greater reliance on strong ligament to stabilise joint

Range of movement variable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Symphyseal joint

A

Found in midline of the body

Articular surfaces =
hyaline cartilage

No joint cavity

Bones how together by a fibrocartilaginous plate

Some ligaments hold the bones together

Range of movement = limited degree

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Typical lumbar vertebra

L1-4

A

There are five vertebrae in the lumbar region but L5 is a-typical

(See photo)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Intervertebral disc

A

24 intervertebral discs and they contribute to a 1/4 of the length of the vertebrae column reason for curvature and spine

Symphyseal joint between intervertebral body and disc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Lumbar discs

A

Biggest within vertebrae column

10 mm thick

Make up a 1/3 of the height of the vertebral column

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Nucleus pulposus

A

Semi fluid or a ball bearing

Irregularly arranged collagen fibres type 2 3D lattice and a few cartilage cells dispersed in a gel of semi fluid ground substance (hold water within its makeup)

Deformable tissue- can change its shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Annulus fibrosis

A

Concentric lamella ( 10–20 layers) of collagen fibres highly organised structure

Within each lamella collagen fibers line parallel to each other at 65–70° angle

Successive layers or a different inclination is to each other i.e. Axa fact provide strength + resilience copes with shearing

Elastic fibres:

1) type l collagen fibres- are in the outermost layer of annulus gives tensile strength
2) type II collagen fibers- inner most layer gives it compressive component

Structure of annulus Is important to maintain the integrity of the intervertebral disc as a whole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Arrangement of annulus fibrosis

Thickenings

A

Collagen lamella are thicker anteriorly and latterly

finer posteriorly

Disc most likely to fail posteriorly

  • If disc prolapse is posteriorly there is chance of spinal-cord entrapment
  • If disc prolapse is posterolatterly there is chance of nerve root entrapment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Vertebral End Plates

Structure

A

Layer of cartilage (0.6-1 mm thick)= hyaline and fibrocartilage

Covers the nucleus but not the entire extent of the annulus fibrosis

Plate is a mixture of hyaline and fibrocartilage:

  • Hyaline- closer to vertebral body weaker link when binding disc to body
  • Outer most fibres of the annulus fibrosis anchor the intervertebral disc to the adjacent vertebral bodies
  • inner surface of end plate is composed of fibrous tissue= inner layers of annulus fibrosis which sweep over and under nucleus fibrosis help to form inner part of vertebral end plate

End-plates are strongly bond to the disks but only weakly attached the vertebral bodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Vertebral End Plates

Functions

A

Protect vertebral body from pressure atrophy because the disc has to cope with pressure

Confinees the nucleus fibrosis and annulus fibrosis within their anatomical range

Acts as a semi-permeable membrane for fluid exchange via osmosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

End Plate+Annulus fibrosis

A

End plate+annulus fibrosis=

Ensures the nucleus fibrosis is completely contained within the intervertebral disc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Nutrition of the disc

A

Discs have a relatively low metabolic rate

Peripheral part of annulus is supplied by adjacent blood vessels

Majority of disk relies on DUFFUSION from blood vessels within the adjoining cancellous vertebral bodies

Diffuses through end plate and into disc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Intervertebral disc

Functions

A

Weight-bearing

Shock absorber

Movement

19
Q

Intervertebral disc- weight bearing

A
  • DISC LOADING– annulus+nucleus are involved in weight-bearing
  • TELEPHONE BOOK ANOLOGY– (annulus) healthy lamella will resist buckling due to the bulk of collagen fibres for a limited period of time
  • Anulus on its own is not sufficient for load bearing has to be combined effort
20
Q

Intervertebral discs – weight-bearing

Disc Looding

A

Compression increases pressure in the nucleus pulposus but due to its deformable nature it changes shape and the force is exerted radially on the annulus and tension in the annulus increases as fibres are stretches

As disc loading increases the tension in the annulus reaches maximum capacity where it can’t stretch any further

As a consequence the nucleus starts to exert pressure on vertebral end plates above and below

As the anulus can no longer stretch and the End plates are a rigid structure which prevent nucleus deforming inferiorly or superiorly = annulus therefore applies an equal and opposite force to that of the nucleus

therefore you end up with a rigid structure through which load can be transmitted

21
Q

Intervertebral disc

Shock absorber

A
  • Rapid application of forced to the disc is diverted momentarily to annulus
  • Annulus have elastic collagen fibres which stretch to absorb the shock and reduce force being passed on to adjacent vertebral bodies
22
Q

Intervertebral disc

Movement

A

Nucleus pulposus acts like a semi fluid ball bearing between adjacent vertebrae

It is able to move with in the confines of the intact annulus

23
Q

Zygoapophyseal joints

A

Synovial plane joints

Articular processes of vertebral column

LX region
•Superior concave facets face medially and posteriorly
•Inferior facets face laterally and anteriorly

Lax fibrous capsule surround to the joint with synovial membrane

Joints are stabilised by additional ligaments

24
Q

Zygoapophyseal joints

Articulations

A

inferior facets of the vertebra above articulating with the superior facets of vertebrae below = joint

Range of movement depends on the shape and orientation of facets

Lots of small movements = quite a bit of movement but still very stable

25
Superior articular facets
concave transversely flat vertically face medially and posteriorly in direction
26
Inferior particular facet
Reciprocally curved they are convex transversely flat vertically closer together than superior facet and face laterally and anteriorly
27
Ligaments supporting vertebral column
1) ALL 2) PLL 3) Supraspinous ligament 4) interspinous ligament 5) ligamentum Flava 6) intertransverse ligament
28
Spinal longitudinal ligament Anterior longitudinal ligament (ALL)
Attaches to anterior part of bodies and discs from C1 to pelvic surface of sacrum widening inferiorly (24mm wide) 1 to 2 mm thick consisting of 3 dense layers Superior fibres= long 7 segmental levels Deepest= 1 segmental level Spinal support for anterior part is vertebrae column
29
Posterior longitudinal ligament (PLL)
Attaches to intervertebral discs and adjacent margins of vertebral column bodies with the vertebral canal Extending from C2 to sacrum 1- 1.4 mm thick consisting of 2 dense layers Superior fibres extensive Deep fibres short
30
Difference between ALL and PLL
Not as strong as ALL PLL attaches to the intervertebral disc and the adjacent margins of the vertebral bodies but it doesn’t attach to the backs of the whole of the vertebral body because it needs to allow space for vertebral vein to pass through to supply nutrition for intervertebral disc
31
Supraspinous ligament
Most posterior Band of longitudinal fibres extending over and connecting the tips of spinous processes from C7 to sacrum Superficial fibres are extensive Deep fibres are shorter Continuous with the posterior edge of the interspinous ligament anterior to supraspinous ligament
32
Interspinous ligament
Thin and membranous Relatively weak best developed in lumbar region Fibres passed between and unite adjacent vertebral ptocesses Particularly well-developed in the Lx region
33
Ligamentum Flava
Passing between both laminae of adjacent vertebrae from C1 to L5 Attaches is to lower border of lamina above the upper border of vertebra below Medial borders of each ligament me at the root of the spine Yellowish a parent due to lots of elastin fibres permits separation of lamina during flexion to allow for a good range of movement but during extension it prevents it + stability
34
Intertansverse ligament
Generally insignificant bands of fibres connecting adjacent transverse processes lower broader of T.p above and superior boarder of T.p below Best developed in the Lx region Absent in the CX region
35
Flexion of vertebral column
ROM: freely moving Effect on intervertebral discs: •Compression of the anterior part of disc •stretching of the posterior part of disc •nucleus moves backwards Effect of facet joints: •inferior articular facet glide upwards on adjacent superior facets Effect on soft tissue : •laminae move apart ``` Limiting factors: increase tension in •Supraspinous Lig •Interspinous ligament •Ligament Flava •PLL •extensor muscles ```
36
Extension of vertebral column
ROM: limited fairly free Effect on intervertebral discs: Compression of posterior part of disc Nucleus moves forwards stretching of anterior part of disc Effect of facet joints: Inferior articular facets glide downwards on the adjacent superior facets = CLOSE PACK POSITION (maximum congruency of articulating surfaces) Effect on soft tissue Spinous processes and laminae move closer together Limiting factors: Increased tension in •ALL •Flexor muscles
37
Lateral flexion of vertebral colum
ROM: free in lumbar region but less than CX region Effect on 6 discs: Six disc compression with some degree of torsion Effect of facet joints: Inferior articular facet glides downwards on adjacent superior articular facet Effect on soft tissue: Laminae move closer together Limiting factors: tension in •Ligaments on the opposite side to the movement •i.e. intertransverse ligament and ligament flava •Opposite muscles
38
Rotation
ROM: very limited = shape and orientation of facets Effect on intervertebral discs: Torsional affect on desk (windeing up) 50% fibrous will be taught in each direction due to the arrangement of them Same side laminae move closer together Opposite side laminae move further apart Limiting factors: increased tension in •Ligaments on both sides •Muscles on opposite side of movement
39
Intervertebral Foreman
Boundaries Superior and inferiorly by pedicles of adjacent vertebrae Anteriorly by vertebral bodies and intervening discs Posteriorly by articular processes and facet joints
40
Intervertebral compression
Any reduction in the transverse dimension of the foramen will result in nerve compression
41
Boundaries of intervertebral foreman
Slightly elongated in the vertical plane Anterior wall: posterior boarder VB Posterior wall: anterior part facet joints Roof: inferior notch of the vertebrae above Floor: superior notch of the vertebrae below
42
What passes through the intervertebral foreman
Spinal nerve root Dorsal root ganglion Segmental spinal artery Spinal communicating veins
43
protection of Vertebral canal
Protected by PLL anteriorly and Lig flava poseriorly