PP 4 Flashcards
What are the articulations of the spinal column?
Zygapophyseal (facet) and Intervertebral (disc)
What type of joint is Zygapophyseal?
synovial, diarthrodial (gliding)
What type of joint is Intervertebral?
symphysis, amphiarthrodial
Spinal Column movements
Flexion, Extension, Right and Left Rotation, and Lateral Flexion
Movements of cervical column.
Flexion and extension, lateral flexion and rotation
Movements of thoracic column
Lateral Flexion (side bending)
Movements of lumbar column.
Flexion and extension
Anterior Longitudinal Ligament
broad, strong band of dense longitudinal fibers which extend along the anterior surfaces of the bodies of the vertebrae, from the axis to the sacrum, broader caudally
Which region is the Anterior Longitudinal Ligament thicker and narrower?
Thicker and narrower in the thoracic than in the cervical and lumbar regions
Where along the spine is the Anterior Longitudinal Ligament thicker and narrower?
Somewhat thicker and narrower along the bodies than at the intervertebral discs
Where is the Anterior Longitudinal Ligament intimatley adherent to the disc?
Is intimately adherent to the discs and the vertebral end plates (top and bottom margins of the vertebrae), but not to the middle of the bodies
How does the Anterior Longitudinal Ligament help the spine?
Helps limit hyperextension of the spine and forward displacement of one vertebra upon another (-olysthesis)
Posterior Longitudinal Ligament
extends along the posterior surface of the vertebral bodies (the anterior surface of the spinal canal)
Describe the look of the posterior longitudinal ligament.
Broad and uniform in width in the cervical and upper thoracic levels.
In the lower thoracic and lumber regions it is narrow and thick over the centers of the bodies and broader over the discs
Where do herniated discs occur and why?
Posterior lateral corners of the intervertebral discs, because they are poorly covered
Ligaments of the Spinal Column
- Tectorial membrane (cephalad), becomes
- PLL
- Cruciate ligament
- Alar ligaments
Alar ligaments
connect the dens to tubercles on the occipital condyle (C2 to skull) and function to check side-to-side movements of the head when it is turned
chief bonds of connection between the vertebrae
The Intervertebral Fibrocartilages
Percentage the intervertebral fibrocartilages comprise of the length of the vertebral column
20-25%
Intervertebral Fibrocartilages correspond with the surfaces of the bodies between which they are placed except where adn what is different?
except in the cervical area where they are slightly smaller from side to side (uncinate processes)
Where are the Intervertebral Fibrocartilages thicker?
Where are they uniform thickness?
- are thicker anteriorly in the cervical and lumbar regions
- are nearly of uniform thickness in the thoracic region
initially, the disc contains approximately _____, - this decreases to about _______, and when? What is this called?
- 85 - 90% water
- 65% in 6th decade
- dissication
the peripheral posterior aspect of the annulus fibrosus is innervated by a few nerve fibers from the _______.
sinuvertebral nerve
The Intervertebral Fibrocartilages with a normal intact disc, the facet joints carry about _____of the axial load, but this may reach ____ with degeneration of the disc
- 20% to 25%
- 70%
The Intervertebral Fibrocartilages consist of three distinct tissues:
- the annulus fibrosus
- the nucleus pulposus
- the vertebral endplates
What is the structure of the Annulus Fibrosus?
- 10-20 concentric rings of collagenous fibers
- criss-cross each other at 30-60 degrees to spinal axis
- Type I collagen primarily
Why the increased strength in the Annulus Fibrosus?
nto accommodate shear and torsional forces
Annulus Fibrosus functions
- Containment of the nucleus
- Stabilization
- Permission of movement
- Minimal shock absorption:
What tye of collagen is Nucleus Pulposus?
Type II
Where is the Nucleus Pulposus located?
ncentral portion of the disc (lies slightly posterior to the center of rotation of the disc in the lumbar spine)
at birth the nucleus contains a high portion of ______which cause the disc to resist deformation however, they decrease with age and are replaced by _____ (degeneration begins to occur after age ___)
- mucopolysaccharides (proteoglycans)
- collagen
- 20
Nucleus Pulposus functions
- Transmission of force (vertical loading)
- Equalization of stress
- Movement
How does the Nucleus Pulposus obtain nutrition?
Mucoid protein and osmotic properties attract fluid across semipermeable membrane of cartilaginous end plate (only periphery of disc is vascularized)
What is the Vertebral Endplate?
thin layers of primarily hyaline cartilage which cover the superior and inferior surfaces of the vertebral bodies
Vertebral Endplate endplates which are approximately ____thick allow nutrient transport in and out of the discs primarily by_____.
- 1 mm
- passive diffusion
Which part of the Vertebral Endplate are vascular? What happens with age?
only the periphery of the disc is vascular and this decreases with age
Vertebral Endplate “Schmorl’s nodes”:
nucleus protruding into the vertebral body through fissures in the end-plates (if nucleus is less compressible than cancellous bone)
Scheuermann disease aka _____
“Juvenile kyphosis”
What is Scheuermann disease?
•Osteochondrosis of the secondary ossification centers of vertebral bodies
What age group is involved and what do they look like with Scheuermann disease?
•13-16 year old adolescents involved, are usually taller, have advanced “skeletal age”
With scheurmann disease, which sex is more affected?
•more boys than girls affected
With scheurmann disease, which nodes are involced?
Schmorl’s nodes
Vertebral Endplate functions
- Protect bone end:
- Transmit weight
- Permit fluid exchange:
What causes disc hernitation?
- Not a result of compression (Þ vertebral endplates go first)
- there needs to be a defect in the annulus and the nucleus must be altered
- PLL usually pushes against nucleus → in case of a herniation the nucleus gets deviated into posterior-lateral direction, where no ligament can push back
Somatic Pain
Any structure that has nerve supply is potentially a source of pain
nociceptive nerve endings stimulated by chemical or mechanical irritation
D.A.Z. P.P.I.
- dura mater (traction and chemicals)
- ALL, PLL
- zygapophyseal joints
- posterior ligaments
- para-vertebral muscles
- intervertebral discs
