Axial Skeleton - Vertebral Column & Thoracic Cage

adult vertebral column

26 bones

• 24 vertebrae (Cervical, lumbar, thoracic)

• 1 sacrum

• 1 coccyx

Functional anatomy of the vertebral column

• Encloses and protects the spinal cord

• Supports the skull

• Supports the weight of the head, neck, and trunk

• Transfers weight to the lower limbs

• Helps maintain the upright position of the body

What types of curves are in the spinal curves category?

Cervical, Thoracic, Lumbar, Sacral

This is the first of the spinal curves / vertebrate regions. What is this region called?

Cervical

This is the second of the spinal curves / vertebrate regions. What is this region called?

Thoracic

This is the third of the spinal curves / vertebrate regions. What is this region called?

Lumbar

This is the fourth and last of the spinal curves / vertebrate regions. What is this region called?

Sacral

Cervical curve / region (7 total)

A secondary curve develops as the infant learns to
balance the head on the vertebrae of the neck

Function

• Support the weight of the head

• Spinous processes are bifid except for C7

• All have transverse foramina

• The transverse processes are fused to the costal processes

• Two have specific names (C1 = atlas, C2 = axis)

Thoracic curve / region (12 total)

A primary curve accommodates the thoracic organs.

All have rib articulation points
• T1 to T8 have superior and inferior costal facets
• T9 to T12 have only one facet
• T1 to T10 have transverse costal facets
• They support the ribs

Most spinous processes point inferiorly

Lumbar curve / region (5 total)

A secondary curve balances the weight of the trunk over the lower limbs; it develops with the ability to stand.

• Support the weight of the torso
• Vertebral bodies are quite large
• Spinous process points posteriorly

Sacral curve / region

A primary curve accommodates the
abdominopelvic organs.

• Includes the sacral + coccygeal regions

• There is one sacrum but consists of five fused
  vertebrae
  

• Joints
  • Lumbosacral joint
  • Sacroiliac joint

What are the movements associated with and specific to the spinal
column?

• Flexion

• Extension

• Lateral flexion

• Lateral extension

• Lateral rotation

Labeled vertebrae

What view of the thoracic vertebrae is this?

Superior view

Vertebral Arch

Forms the vertebral foramen
• Made of pedicle and laminae
• Spinous process projects posteriorly
• Transverse processes project laterally

What is spina bifida?

Malformation of the structures making up the
vertebral arch, where the vertebral arch fails to
close completely

• Folate deficiency can be a contributing factor

• Pregnant women should take folic acid supplement as form of prevention

What are the functions and divisions of the articular processes?

• Superior articular process

• Inferior articular process

• These allow adjacent vertebrae to join each other

Vertebral Articulation

Vertebrae have articular facets and a vertebral canal
• Vertebral bodies are separated by intervertebral discs
• This results in creating a space called the intervertebral foramina

Vertebral anatomy (again labeled)

What does this represent?

intervertebral foramen and discs

What does this represent?

Superior view of cervical vertebrae

Atlas and Axis

The Atlas (C1)
• Articulates with the occipital condyles of the skull
• Does not have a body
• Consists of anterior and posterior vertebral
arches/anterior and posterior tubercles/superior
articular facets/inferior articular facets
• Has the largest vertebral foramen of all vertebrae
• Allows the head to nod in a “yes” manner

The Axis (C2)
• Has a dens
• The transverse ligament binds the dens to the atlas
• Allows the head to move in a “no” manner

Vertebral Prominens (C7)

C7 has a long prominent spinous process

Ligamentum nuchae
• Large elastic ligament
• Begins at the vertebral prominens and extends to
the external occipital crest of the skull

Where is the greatest range of motion in the cervical spine?

C3 to C7

Where is the Ligamentum Nuchae located?

What is represented by this image?

Lateral view of lumbar vertebra

Coccyx

Consists of three to five fused vertebrae
• Adult male coccyx points anteriorly
• Adult female coccyx points inferiorly
• coccygeal cornu – articulation with sacrum

What view of the sacrum + coccyx is this?

Posterior

Thoracic cage

Function
• Protection
• Attachment site for muscles

Ribs
• True ribs/ vertebrosternal ribs (1-7)
• False ribs / vertebrochondral ribs (8-10)
• Floating ribs (11-12)

Structures of a rib

• head

• neck

• body

• tubercle

• angle

• costal groove

• Sternal end -superior and inferior articular
  facets/interarticular crest

The Sternum

Consists of:
• Manubrium
• Body
• Xiphoid process
• Jugular notch

The image on the left is a “normal” spine. What is the type of spine on the left referred as?

Kyphotic spine

What view of the Sacrum + Coccyx is this?

Anterior view

Are false ribs directly connected to the sternum?

No; they are indirectly connected

What joint in the Sacral region do you NOT need to know?

Sacrococcygeal joint

Do the atlas (C1) and axis (C2) share a direct connection?

Yes, via a joint

What feature is unique to cervical vertebrae?

Transverse foramen