The Vertebral Column Flashcards
The Vertebral Column
24 mobile segments (vertebrae)
^separated by flexible cartilaginous discs (intervertebral discs)
Immobile base made up of 9 fused vertebrae: sacrum and coccyx
Functions: protects spinal cord and nerves // supports trunk as a rigid yet flexible axis for the body // important for posture and locomotion // muscle attachment
Primary and Secondary Curvatures
Primary: Develop during fetal period
Newborn spine = kyphotic (anteriorly concave)
- *Secondary:** Result from development of spine in first few years of life
- *Lordotic** curves = concave posteriorly
- *Cervical lordosis:** develops when infants begin to hold their head up
- *Lumbar lordosis:** develops when toddlers begin standing and walking
Abnormal Spinal Curvatures
Excessive Thoracic Kyphosis
aka hunchback
common in elderly
caused by degeneration and years of bad posture
Excessive Lumbar Lordosis
sway // hollow back
often temporary, common in pregnant women
due to additional weight in abdomen
Scoliosis
abnormal lateral curvature of the spine
spine will twist/curve off the midline of the body
Scoliosis
Abnormal lateral curvature of the spine
Spine curves to one side and vertebra try to compensate by rotating INTO the cavity of the curvature
Common in females aged 12-15
Functions of Column
Anterior Portion (body):
supports weight of body and absorbs shock
Central Portion (opening):
protects spinal cord
Posterior Portion (processes):
muscle attachment and movement of column
Important Vertebral Features
General Vertebral Anatomy: T6 and L2
Vertebral Foramen and Vertebral Canal
- *Vertebral Foramen**
singular: through which spinal cord passes
Vertebral Canal
consecutive vertebral foramina, through which spinal cord passes
General Vertebral Anatomy - Lateral Lumbar View
Cervical Vertebrae
Seven vertebral segments (C1-C7)
Lordotic curvature
Regional Anatomy:
large vertebral foramen and small body
bifid spinous process
transverse process has transverse foramen (houses vertebral artery)
Cervical Vertebrae Regional Anatomy Contd.
Bifid spinous process
C7 → non bifid and longest cervical spinous process
aka vertebra prominens
Transverse process has transverse foramen (houses vertebral artery)
Superior and inferior articular processes stack up on each other to form lateral “columns”
Specialized Cervical Vertebra: C1
Atlas (C1)
no body (anterior tubercle)
facet for joint
no SP (posterior tubercle)
widest
Specialized Cervical Vertebra: C2
Axis (C2)
dens (facet for joint)
axis of rotation
Images of Cervical Vertebrae
Vertebral Bodies C3 to C7
Find rib #1 and count bodies superiorly
Vertebral discs appear radiolucent between bodies
Transverse processes stick out laterally
Pedicles (eyes of the bird face)
Spinous Process (beak of bird face)%
Imaging of Cervical Vertebrae
Thoracic Vertebrae
12 vertebral segments (T1-T12)
^each associated w/ a pair of ribs
Kyphotic curvature
Regional Anatomy:
heart shaped body
long, inferiorly angled spinous process
costal facets on body and transverse processes for rib attachment
Imaging of Thoracic Vertebrae
Look for 1st rib
Count vertebral bodies inferiorly from it
Examine disc spaces
Pedicles
Spinous processes
Look for abnormal curvatures
Look at rib attachments (ribs w/ transverse processes)
Imaging of Thoracic Vertebrae Contd
Lumbar Vertebrae
5 Vertebral Segments (L1-L5)
Lordotic Curvature
Regional Anatomy
LARGE vertebral bodies, which bear the most weight
Large vertebral foramen to accommodate lumbar enlargement of spinal cord
Spinous process = thick and short
Transverse process = thin and small
Lumbar Vertebrae
Imaging of Lumbar Vertebrae
The Sacrum
Large wedge-shaped vertebra at the inferior end of the spine
Supports weight of the upper body
Superiorly articulates w/ body of L5, inferiorly articulates w/ coccyx
Laterally articulates w/ hip bones to form pelvic girdle
Forms from 5 individual vertebrae that start to fuse during late adolescence and = fully fused by the age of 30
The Sacrum Contd.
- *S1-S5 = sacral body**
- *S1 - Sacral promontory**
Ala of Sacrum
TBPs of S1 vertebrae
Sacral foramina (anterior and posterior)
Formed from intervertebral foramen
Transverse ridges
Remnants of intervertebral discs between sacral vertebrae
The Sacrum Contd.
Sacral Canal
continuation of vertebral canal
Median Crest
fusion of SPs
Sacral Foramina
intervertebral foramina
Sacral Hiatus
lamina of S5 vertebrae (non-fused)
exit for last spinal nerve (coccygeal nerve #1)
Imaging of Sacrum X
The Coccyx
Tail Bone
End of Spine
Kyphotic Curvature
Coccygeal vertebrae = highly variable and can range from 3-5 segments (4 is most common)
Intervertebral Discs
Functions:
Strong attachment between vertebrae for Support and protection
Weight bearing / shock absorption
Make up approximately 25% of column height
- *Composed of:**
- *annulus fibrosus →** concentric rings of fibrocartilage that connect adjacent vertebral bodies
- *nucleus pulposus →** semi-gelatinous mass that acts as a shock absorber
NOTE: discs are named after the vertebral segments they connect
NO DISCS BETWEEN atlanto-occipial joint, atlanto-axial joint, sacral segments, and coccygeal segments
Joints of the Spinal Column
Vertebral bodies = stacked on each other in the column and form 2 types of joints as they articulate w/ each other
Movement of the Vertebral Column
Specialized Facet Joints
Vertebral bodies = stacked on each other in the column and form 2 types of joints as they articulate w/ each other
C1/C2 Dislocation
**Abnormal x-ray** huge distance (black line) between the dens and anterior arch of C1 (blue arrow)
white line show the continuation of lamina → C1 is displaced anteriorly (red arrow)
Organization of the Spinal Column
Vertebral Canal
aka spinal canal
protects spinal cord
Intervertebral Foramen
protects spinal nerves as they exit from the cord
Organization of Spinal Nerves
31 pairs of spinal nerves exiting off spinal cord and enter periphery by passing through intervertebral foramen
Spinal nerves = mixed in their function (sensory and motor signals)
motor signals = efferent/outgoing
(brain → body)
sensory signals = afferent/incoming
(body → brain)
Anatomical placement of Spinal Nerves
Herniation/Protrusion of Intervertebral Discs
Unilateral herniation
when nucleus pulposus protrudes through the annulus fibrosis
Typically occurs postero-lateral direction
leads to compression of the ipsilateral spinal nerves exiting the IV foramen
Most common in C and L regions (L4/L5 L5/S1)
s&sx:
pt presents w/ numbness/tingling ipsilaterally (typicality after minor injury/strain to area)
Imaging of IV Disc Herniations
Spinal Stenosis
Narrowing of spinal canal, compressing the spinal cord or nerves of caudal equina
Caused after long term degeneration of intervertebral joints
s&sx
pt presents w/ numbness and tingling in both sides
compression of spinal nerves bilaterally (L and R)
***NOTE: stenosis = general term for NARROWING of a lumen
Laminectomy
tx for spinal stenosis
involves surgical removal of vertebral lamina to relieve pressure on vertebral canal
Regional Characteristics
