The Spine
Mr. Brewer
The Spine
The Spine is broken down into 5 major
sections of Vertebrae:
- Cervical
- Thoracic
- Lumbar
- Sacrum
- Coccyx
The spine is designed to not only provide
structure to our skeleton, but also to have
flexibility to allow for mobility.
Having the spine composed of individual
vertebrae with space in between each is
primarily what allows for this mobility at
the core.
Vertebrae
The spine is broken down into different sections, and although each
section has unique features that make them different from one another,
all (most) vertebrae are structured VERY similarly from top to bottom.
What is similar? What is Different?
Vertebrae Anatomy
• Vertebrae from C1-L5 all
share very similar traits.
• Few exceptions to the
overall composition of a
vertebrae include C1 and
C2 because of the role
they play allowing
movement of the head.
• The rest of the vertebrae
all have the following
components:
–
–
–
–
–
Spinous Process
Body
Pedicle
Transverse Process
Superior AND Inferior
Articular Facets
– Lamina
– Spinal Canal
Cervical Spine
• The Cervical spine is the
most superior aspect of
the Spinal Column.
• There are 7 total cervical
vertebrae, the top 2 are
unique from most other
vertebrae.
• They (C1 and C2) are
known as the Atlas and
Axis.
• When compared to the
other vertebrae, C3-C7
are very similar to the
rest of the vertebrae in
the spinal column, but
are smaller in size.
Atlas and Axis
• The 2 most superior vertebrae are known better as the
Atlas and Axis.
• Both are considered to be cervical vertebrae(C1 and C2),
but are unique and play a crucial role in allowing mobility
of the human head.
Atlas and Axis Continued
• The Atlas (C1) does not have a body
like the rest of the vertebrae, but
has a space to allow the spinal cord
to travel through, and also has 2
smooth surfaces for the Occipital
Condyles of the skull to sit on top
of.
• The Axis (C2) sits directly under the
Atlas and provides a surface for the
atlas to rotate on. This allows for
lateral rotation of the head.
• The DENS: is a prominent aspect of
the Axis bone that projects up
through Atlas for additional
structure and stability. It also acts
as a pivot point for the Atlas.
• https://www.youtube.com/watch?v
=b5NjhaG2SbY
Thoracic Vertebrae
• 12 vertebrae that
are between the
cervical and
lumbar vertebrae
or known as the
Thoracic
Vertebrae.
• These vertebrae
make up the “midback”.
• These vertebrae
have a direct
correlation with
the Ribcage.
Thoracic Vertebrae and
the Ribcage
• 12 Ribs and 12 Thoracic
Vertebrae.
• Each Rib attaches itself
snug in between the “T”
vertebrae.
• The Ribs are “numbered”
1-12 from superior to
inferior.
• They are named in
correlation for the “T”
vertebrae that they sit ON
TOP of. (Picture provides
visual representation.)
• Ribs 11-12 are known as
False Ribs because they
have no connection to the
sternum via costal
cartilage.
Lumbar Vertebrae
• The thickest and largest
individual vertebrae of
the spinal column.
• There are 5 Lumbar
vertebrae, and they
provide the most
support to the spine,
but have the least
mobility in terms of
flexion and extension.
• The most notable
difference from the
other vertebrae,
besides the thickness,
is the spinous process.
Components of the Spinal Region
In between each vertebrae, is
a disc that is made of
cartilage.
The outer aspect of this disc is
just cartilage tissue called the
Annulus Fibrosus.
In the middle of the annulus
fibrosus there is a viscous
fluid called the Nucleus
Pulposus. This is “jelly-like” in
it’s composition.
That Sacrum and Coccyx
As we discussed during the Hip and Pelvic unit, the Sacrum and Coccyx are the most distal
aspect of the spine.
The Sacrum is typically 5 fused vertebrae that lies directly between the Pelvic bones.
- The Sacrum has foramen on both sides just lateral to the center line of the Sacrum to
allow nerves and blood vessels to travel to the hip and legs.
The Coccyx is anywhere from 3 to 5 fused vertebrae, and is also known as the “Tail Bone”.