Vertebral Column and Thoracic
Cage Notes
Vertebral Column
• 33 bones in infants
• 26 bones in adults
• 5 sections:
– Cervical (7 bones)
– Thoracic (12 bones)
– Lumbar (5 bones)
– Sacrum (5 fused bones)
– Coccyx (4 fused bones)
Vertebral
Curvatures
Primary – those present
at birth:
• thoracic
• pelvic
Secondary – develop
after birth:
• cervical – develops as
baby holds head up
• lumbar – develops as child
begins to stand
Features of Typical Vertebrae
body – for support
intervertebral arch – for articulation of next vertebrae
sup. & inf. articulating processes – for articulation w/vert.
above or below
Features of Typical Vertebrae
rib facet – for articulation w/ribs
transverse processfor muscle attachment;
project laterally
spinous process - sharp projection for muscle attachment
projects posteriorly
lamina – 2 plates that fuse to become spinous process
pedicle – projection from body
vertebral foramen – opening for s.c.
intervertebral disc – composed of cartilage for cushion
Features of Atlas (C1)
Atlas – supports skull
• Fovea dentis – notch for dens
• Facet for articulation w/occipital condyles
• No body
Features of Axis (C2)
Axis – pivot point
• Dens (odontoid
process); fits into
C1 for rotation
of the skull
Cervical Vertebrae (7)
Features:
• smallest
• most dense
• transverse foramina – for arteries to brain
• bifid (forked) spinous process (C2-C5)- (for muscle attachment)
• C7 –
vertebra
prominens
(landmark)
Thoracic Vertebrae (12)
Features:
• larger than cervical
• long spinous process
projects posteriorly
and inferiorly
• facets for ribs
Lumbar Vertebrae (5)
Features:
• Largest, strongest
bodies
• Transverse process
thinner & project laterally
• Spinous process
short, thick, nearly
horizontal
Sacrum & Coccyx
Sacrum – triangular-shaped bone at base of vert. column
•Consists of 5 fused vertebrae
•Sacral foramen – for b.v. & nerves
•Sacral canal – s.c. travels through
•Sacral hiatus – where spinal cord exits
Coccyx (tailbone) – consists of 4 fused vertebrae
Thoracic Cage
Includes ribs, thoracic vert.,
sternum & costal cartilage
Support upper limbs,
protect organs & aid in
breathing
Sternum – 3 parts:
manubrium
body
xiphoid process
Features of Sternum
• Sternal angle – union of
manubrium & body; at 2nd
rib (anatomic landmark)
• Clavicular notch – junction
of clavicle & sternum
• Sternal puncture – aspiration
of red marrow for diagnosis
Ribs – 12 pair
3 types:
vertebrosternaltrue ribs (1st 7pair)
vertebrochondral –
false ribs (next 3 pr.)
vertebral – floating (last
2 pair)
Male vs. Female Pelvis
Female Structure (All related to
female pelvis functioning as a birth
canal):
• Iliac bones more flared
• Angle of pubic arch greater
• > distance b/t ischial
spines
• Sacral curvature shorter
& wider
• Bones lighter