Marieb - Chapter 7, 5.2b

Vertebral column

Introduction

  • axial support of the body

  • from the skull to the pelvis where it transmits the weight

  • 26 bones, between them an intervertebral disc, the spinal cord in the center, and surrounded by ligaments

  • Sacrum + coccyx + 7 CV + 12 TV + 5 LV

Note:

  • primary curvatures → TV + LV (they are present when we are born)

  • secondary curvatures → CV (they develop after birth)

Intervertebral discs

  • cushion, shock absorber

  • herniation due to aging or due to twisting forces

Structure patterns of the vertebrae: what they have in common

  • Body → facing the anterior part of the column, bears weight

  • Vertebral arch → arch formed from the joining of all posterior extensions, (laminae and pedicles) from the vertebral body

  • Vertebral foramen → canal through which the spinal cord passes

  • Transverse process → 2 lateral projections from the vertebral arch

  • Spinous process → single projection arising from the posterior aspect of the vertebral arch

  • Superior + inferior articular process → projections at the lateral of the vertebral foramen, allow a vertebrae to form joints with other vertebrae

Cervical vertebrae (C1 - C7)

C1 → atlas has no body, transverse process contains large depression to accommodate the occipital condyles of the skull (YES joint)

C2 → axis, pivot function, large upright process (dens)

  • The joint between C1 and C2 allows to do “NO”

Typical CV: C3 to C7

  • small, light

  • spinous process divided in 2 branches

  • transverse processes contain foramina (openings) for arteries

Thoracic vertebrae (T1 -T12)

  • they are all typical

  • larger than CV

  • only vertebrae to articulate with ribs (2 costal facets that articulate with them on the side, they receive the head of the ribs)

  • The transverse process articulates with tubercles of ribs

  • The spinous process is sharply downward

Lumbar vertebrae (L1 - L5)

  • the biggest type

  • short spinous process

Sacrum

  • formed by 5 vertebrae fused

  • articulates above with L5 and inferiorly with coccyx

  • Each wing articulates with hip bone → Sacroiliac joint

  • the sacrum formed the posterior wall of the pelvis

  • posterior surface → median sacral crest

  • there are some longitudinal openings → posterior sacral formaina

  • the vertebral canal continues inside the sacrum with → sacral canal and it end with the sacral hiatus (large inferior foramina)

Coccyx

  • fusion of 3 to 5 bones

  • “tailbone“