Structure & function of lumbar intervertebral disc Flashcards
What is the basic structure and function of the lumbar spine?
Consists of 5 vertebrae (L1, L2, L3, L4 and L5)
Has lordosis- c shaped inwards curve
The 5 vertebrae are connected in the back by facet joints - enables forward & backward extensions + twisting movements
Other types of joints:
- Cartilaginous joint between vertebral bodies
- synovial type joint between vertebral arches.
Function:
- Largest vertebrae- must support weight of person’s body whilst standing.
NOTE: view note for image!
Describe the structure and function of the intervertebral discs
Consists of a central nucleus pulposus surrounded by the annulus fibrosus
Annulus fibrosus - consists mainly of types I & II collagen
- Provides circumferential flexibility & strength to the lumbar intervertebral discs.
Nucleus pulopsus - a pulplike gel located in the mid-to-posterior part of the disc. Thickened intogel-like consistency by proteoglycans.
- Provides shock absorption system capable of dissipating & transferring energy across consecutive vertebra.
Vertebral endplate - a bilayer of bone & cartilage, which separates the intervertebral discs from the adjacent vertebrae.
- NOTE: Not found in the sacrum or coxyxx or upper cervical region (because we have 2 special joints instead).
NOTE: view notes for image !
Name 5 functions of the lumbar intervertebral discs.
- Distribution of compressive loads placed on spine
- Maintaining the distance between the vertebral bodies during movement
- Providing flexibility to spine
- Prevention of excessive movements
- Creating & maintaining the lordotic curve of the lumbar spine
IMPORTANT NOTE: Lumbar intervertebral discs are most likely to degenerate or herniate, leading to lower back pain or pain radiating to legs
What happens to the lumbar intervertebral disc in health and disease?
In health
- normal
- mentioned above
In disease:
- PROLPASED DISC!
- view notes on prolapsed disc!
