Lumbar Spine (sacrum + Coccyx) Flashcards
Vertebral column functions
Posture
Locomotion
Weight bearing
Protection of spinal cord
Haemopoiesis - bone marrow
Outline the development of the spine
HOX genes signal somites
Somites become dermomyotome + Sclerotome
Sclerotomes»_space; vertebrae + ribs
What curvature does the cervical spine form?
Lordosis
What curvature does the thoracic spine form?
Kyphosis
What curvature does the lumbar spine form?
Lordosis
Development of the curvature of the spine
C - lordosis - develops as infant holds head up
T - kyphosis
L - lordosis - develops as learning to walk
What type of bone is the body of the lumbar vertebra composed of?
10% corticoid
90% cancellous > Haematopoiesis + decreases the weight of the bone
How is the lumbar vertebrae angled?
90° to axial plane
45° to coronal plane
Outline the structure of intervertebral discs
Annulus fibrosus on edges
Nuclear pulposus in centre
Outline the structure of annulus fibrosus
Comprised of lamellae - outer: type 1 collagen
- inner: fibrocartilaginous
Avascular + aneural
Outline the structure of nuclear pulposus
Remnant of notochord
Consists of type II collagen
Acidic environment
Why are you shorter at the end of the day than the start?
Fluid pushed out of nuclear pulposus in intervertebral discs due to mechanical pressure
Articulation of the sacrum
superiorly - L5
laterally - ilium of pelvis
inferiorly - coccyx
Where does the central canal of vertebral column end?
S4 - sacral hiatus
What does the cauda equina innervate?
Lower limbs
Pelvic organs
