Session 5 Anatomy Flashcards
Lumbar spine
5 lumbar vertebrae, 5 sacral, 4 coccygeal (last 2 groups are fused to give 2 inominate structures sacrum and coccyx)
Lumbar vertebrae are
Mobile
Functions of lumbar spine
Support, protection, movement, haemopoiesis
Support thoracic spine and pelvis, protect spinal cord and cauda equina, highly flexible structure of bones, intervertebral discs and ligaments, red marrow
Why does the size of the vertebral body increase from superior to inferior
To resist the greater compressive forces distally
What does interlocking of facet joints do
Allows amount of flexion, lateral flexion and rotation
Prevents anterior displacement of vertebrae
Types of joints in the lumbar spine
Fibrous (non-mobile) e.g. sacroiliac joint
Secondary cartilaginous (partially mobile) e.g. intervertebral discs
Synovial joints (highly mobile) e.g. facet joints
2 regions of intervertebral discs
- nucleus pulposus (central)
- Annulus fibrosis (peripheral)
What is annulus fibrosis
Surrounds nucleus pulposus
Type 1 collagen
Made from lamellar of annular bands
Avascular and aneural
What is nucleus pulposus
Remnant of notochord
Gelatinous, type 2 collagen
high oncotic pressure
Major shock absorber, highly resilient under compression, stronger than vertebral body, keep vertebrae separate
What do ligaments do
Provide stability and provide limits to ROM
2 anterior region ligaments
Anterior longitudinal ligament
Posterior longitudinal ligament
3 posterior ligaments
Supraspinous ligament
Interspinous ligament
Ligamentum flavum
What happens to force transmission with age
Greater forces through the facet joints as disc narrower
Anterior longitudinal ligament
Wider than PLL, mobile over intervertebral discs, prevents hyperextension
Posterior longitudinal ligament
Weaker than anterior longitudinal ligament
Prevents hyper flexion
Reinforces annulus centrally leading to paracentral disc prolapses
