Axial Skeleton: Vertebral Column
Axial Skeleton: Vertebral Column
Topics Covered
Introduction
Vertebrae
Cervical vertebrae
Axis
Atlas
Thoracic vertebrae
Lumbar vertebrae
Sacral and coccygeal vertebrae
The rib cage
Ribs
Sternum
Hyoid bone
Introduction (Linked to figure 7.20- Vertebral Column)
· Made of 26 bones namely cervical, thoracic, lumbar, sacral and coccyx vertebrae
· Protects your spinal cord
· In humans the vertebrae increase in size from the cervical to the lower lumbar vertebrae – this is due to the increase in weight on the lower vertebrae.
· The number of vertebrae in each section line up with times of day one eats meals à cervical = 7, thoracic = 12, lumbar = 5.
Vertebrae
· Body or centrum
· Spinous process
· Vertebral foramen
· Transverse process
Cervical Vertebrae (Linked to figure 7.25- Cervical Vertebrae)
**C1-C7**
· 3 foramina:
o (1 vertebral foramen + 2 transverse foramina)
· Some have bifid spinous processes (split in two – bifurcated)
· Smaller, lighter weight bodies
· All cervical vertebrae have three formina and they have the smallest and lightest bodies when compared to the other vertebrae.
Atlas
*C1*
· 1st cervical vertebrae
· Only cervical vertebrae without a body
· Provides for the range of motion as nodding your head “yes”
· Superior articular facets articulate with the occipital condyles of the skull
Axis
*C2*
· The 2nd cervical vertebra
· Unique superior process, called the dens or odontoid process runs through the atlas
· Dens allows the atlas to rotate on the axis
· Provides for the range of motion as shaking your head “no”
Thoracic Vertebrae (Linked to figure 7.26- Thoracic Vertebrae)
**T1-T12**
· Medium sized body with markings on the lateral, posterior surface (attach to ribs)
· Long, narrow spinous process that commonly slants inferiorly
· Facets on the transverse process that articulate with the ribs
Lumbar Vertebrae (Linked to figure 7.28- Lumbar Vertebrae)
**L1-L5**
· No transverse foramina
· No rib facets
· Largest bodies
· Thick spinous processes that extend horizontally
Sacrum & Coccyx (linked to figure 7.29- Sacrum and Coccyx)
· The coccyx is actually 3-5 fused bones
The Rib Cage (Linked to figure 7.32- Thoracic Cage)
· Made of 25 bones (24 ribs and the sternum)
Ribs (Linked to figure 7.32- Thoracic Cage)
• Also called costae
• First seven pairs – True ribs as their costal cartilage attaches directly to the sternum
• Remaining five pairs – False ribs
• Pairs 11 and 12 - Floating ribs as they do not join with sternum
Sternum (Linked to figure 7.32- Thoracic Cage)
• 3 parts
o Manubrium (on top)
o Body (middle, main part)
o Xiphoid Process (lowest tip)
Hyoid Bone (Linked to figure 7.19- Hyoid Bone)
· A horseshoe-shaped bone found in the neck between the chin and the thyroid cartilage
· Only distantly articulates to other bones by muscles and ligaments
· Important for swallowing and sound production