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Question 1

Overview of the vertebral column

• How many vertebrae total?
• How many mobile and fused?
• How many in each section?
• What are the functions of the vertebral column?

Answer 1

Overview of the vertebral column

• Part of the axial skeleton (which also includes the skull, ribs, and sternum)
• Total of 33 vertebrae (24 mobile, 9 fused)
  
  • 7 cervical
  • 12 thoracic
  • 5 lumbar
  • 5 sacral
  • 4 coccygeal

Functions of the vertebral column

• Protect spinal cord and spinal nerves
• Posture and movement
  
  • Supports and transmits weight of body
  • Provides a relatively flexible axis for torso and head
  • Movements include: extension, flexion, lateral flexion, and rotation

Question 2

Curvatures of the vertebral column

• Primary and secondary curvatures
  
  • What are they?
  • Also called?
  • Location in spine?
  • Develop when / how?
• Abnormal curvatures
  
  • Excessive thoracic kyphosis?
  • Excessive lumbar lordosis?
  • Scoliosis?

Answer 2

Curvatures of the vertebral column

• Primary curvatures (kyphoses)
  
  • Thoracic and sacral
  • Project out posteriorly / concave anteriorly
  • Develop early in ontogeny during fetal period when entire vertebral column is concave anteriorly
• Secondary curvatures (lordoses)
  
  • Cervical and lumbar
  • Project out anteriorly / concave posteriorly
  • Cervical develops in response to infant learning to hold head upright
  • Lumbar develops in response to infant learning to sit upright and walk

Abnormal curvatures

• Excessive thoracic kyphosis
  
  • “Humpback”
  • Exaggerated thoracic curvature
• Excessive lumbar lordosis
  
  • “Swayback”
  • Exaggerated lumbar curvature
  • Can occur during pregnancy
• Scoliosis
  
  • Lateral deviation AND rotational component

Question 3

Features of the vertebae

• How does the vertebral body change in size?
• What two structures form the vertebral arch?
• Location of the spinous, transverse, and articular processes?
• What do the articular processes articulate with?
• What forms the vertebral canal?
• Vertebral notches are located on the superior or inferior aspects of?
• What transverses the intervertebral foramen?

Answer 3

Features of the vertebae

• Vertebral body
  
  • Anterior
  • Articulates with the intervertebral disks
  • Supports body weight, so it increases in size from cervical to superior sacral regions. Then weight is transferred through SI joints to pelvis and LE, so vertebral bodies decrease in size from mid sacral to coccygeal region.
• Vertebral (neural) arch
  
  • Posterior to the vertebral body
  • 2 pedicles attached to vertebral body
  • 2 laminae attached to pedicles
• Spinous processes (posterior projections)
• Transverse processes (lateral projections)
• Articular processes
  
  • Superior and inferior projections
  • Superior processes articulate with the inferior processes of vertebra above
  • Inferior processes articulate with superior processes of vertebra below
  • Facet = smooth articulate surface, forms facet joints (zygapophysial joints)
• Vertebral foramen
  
  • Formed by the vertebral arch and posterior surface of the vertebral body
• Vertebral canal
  
  • Contains spinal cord and associated structures
• Vertebral notches
  
  • 2 superior and 2 inferior notches per vertebra
  • Located on the superior or inferior aspect of the pedicles
  • Adjacent superior and inferior notches help form an intervertebral foramen
• Intervertebral foramen
  
  • Blood vessels and spinal nerves transverse here

Question 4

Cervical vertebrae

• How many?
• Small bodies because?
• Which vertebrae is called the vertebra prominens and why?
• Only cervical vertebrae have what two structures?
• Atlas
  
  • Which vertebrae?
  • Lacking what structures?
  • What do the superior and inferior articular facets articulate with?
• Axis
  
  • Which vertebae?
  • Contains what structure?

Answer 4

Cervical vertebrae

• 7 total
• Small vertebral bodies (supporting less weight)
• C7 is called the vertebra prominens because it has the most prominent cervical spinous process
• Only cervical vertebrae have:
  
  • Transverse foramina: holes in transverse processes for passage of vertebral vessels
  • Uncinate processes: elevation of superiorlateral margin of body
• Atas (C1)
  
  • No vertebral body or spinous process
  • Ring shaped
  • Superior articular facets articulate with the occipital condyles of the cranium
  • Inferior articular facets articulate with the superior articular facets of the axis (C2)
• Axis (C2)
  
  • Dens process: AKA odontoid process (snaggle tooth)
  • Larger superior articular facets to articulate with inferior articular faceets of atlas (C1)

Question 5

Thoracic vertebrae

• How many?
• Entire vertebrae shaped like?
• Bodies shaped like?
• Shape of the spinous processes?
• Only thoracic vertebrae have what structure?

Lumbar vertebrae

• How many?
• Entire vertebrae shaped like?
• Bodies shaped like?
• Where are spinal taps and lumbar anesthesia performed?
• Lumbosacral angle is inbetween what?

Answer 5

Thoracic vertebrae

• 12 total
• Giraffe
• Heart shaped bodies
• Spinous processes are long, slender, and slant inferiorly to the level of the vertebral body below
• Only thoracic vertebrae have costal facets for articulation with ribs

Lumbar vertebrae

• 5 total
• Moose
• Kidney shaped bodies
• Robust spinous processes
• Lumbar puncture (spinal tap) and lumbar anesthesia performed between the gaps of lumbar spinous processes
• Lumbosacral angle marks junction of L5 vertebra and sacrum

Question 6

Sacrum

• How many?
• Vertebral canal continues as?
• Fused spinous processes form?
• Sacral hiatus
  
  • Location?
  • Bounded laterally by?
  • Clinical significance?

Coccyx

• How many?
• Focal point for what attachments?

Answer 6

Sacrum

• 5 vertebrae fused together
• Vertebral canal continues as sacral canal
• 4 pairs of anterior and posterior sacral foramina
• Fused spinous processes of the sacral vertebrae form the median sacral crest
• Sacral hiatus
  
  • Distal opening of the sacral canal
  • Bounded laterally by the palpable sacral cornua
  • Hiatus can be used to administer caudal epidural anesthesia

Coccyx

• 4 vertebrae fused together
• Focal point for muscle (e.g. pelvic diaphragm) and ligament (e.g. sacrospinous ligament) attachment

Question 7

Intervertebral (IV) disks

• Functions?
• Difference between thoracic vs cervical/lumbar IV disks?
• Which region is more suspectible to herniation and why?
• Outer fibrocartilaginous ring called?
• Inner gelatinous central mass called?
• Significance of this central mass during the day and with age?

Answer 7

Intervertebral (IV) disks

• Functions:
  
  • Distribute force and weight
  • Provide flexibility to vertebral column (esp. cervical and lumbar regions)
• Thoracic IV disks are thin and uniform in shape
• Cervical and lumbar IV disks are thick anteriorly (contributing to the secondary curvatures), which makes these regions more susceptible to herniation
• Components of IV disk:
  
  • Anulus fibrosus
    
    • Outer fibrocartilaginous ring
  • Nucleus pulposus
    
    • Inner part
    • Gelatinous central mass
    • High water content that decreases during the day and with age
    • Provides shock absorption

Question 8

Joints of the vertebral column

• Where do bone spurs occur?
• What joints cause “yes” and “no” movements?
• Cartilaginous (symphyses) joints
  
  • Joints of? Consists of?
• Uncovertebral joints of Luschka
  
  • Located between?
• Facet (zygapophysial) joints
  
  • Located between?
  • What is the orientation of the cervical, thoracic, and lumbar articular facets and what movements do they do?

Answer 8

Joints of the vertebral column

• Cartilaginous (symphyses) joints
  
  • ​Joints of vertebral bodies
  • Consists of IV disks and ligaments
• Uncovertebral joints of Luschka
  
  • Located between the uncinate processes of the cervical vertebrae and the body of adjacent vertebrae
  • Site of bone spur formation, causing neck pain
• Facet (zygapophysial) joints
  
  • ​Synovial joints between articular processes of adjacent vertebrae
  • Orientation of facet joints helps determine mobility of region, permitting gliding movements between vertebrae
    
    • Cervical articular facets face superiorly and inferiorly, permiting flexion, extension, lateral flexion, and rotation (all motions)
    • Thoracic articular facets face anteriorly and posteriorly, permiting rotation (ribs limit movement)
    • Lumbar articular facets face medially and laterally, permitting flexion, extension, and lateral flexion (restrict rotation)
• Atlanto-occipital joints
  
  • Synovial joint between cranium and atlas (C1)
  • Flexion and extension of head - nodding “yes”
• Atlanto-axial joints
  
  • ​Synovial joints between atlas (C1) and axis (C2)
  • Rotation of the head - shaking “no”
  • Three joints total:
    
    • Median
    • Lateral (2) facet joints

Question 9

Osteological landmarks of the back

• Spinal levels of:
  
  • Vertebra prominens
  • Inferior angle of the scapula
  • Iliac crests

Skin and fascia of the back

• Nuchal ligament
  
  • Thickening of what ligament?
  • Location?
  • Attaches where?
• Thoracolumbar fascia
  
  • Location?
  • Surrounds?

Answer 9

Osteological landmarks of the back

• External occipital protuberance of the occipital bone
• Mastoid processes of the temporal bones
• Spinous processes, including vertebra prominens (C7)
• Inferior angle of the scapula (level of T7)
• Iliac crests (level of L4)

Skin and fascia of the back

• Segmental nerve supply via the dorsal rami
• Dorsal rami include motor and sensory fibers (e.g. somatic motor, somatic sensory, and sympathetic fibers)
• Blood supply and drainage via segmental vessels (e.g. branches of intercostal arteries/veins and lumbar arteries/veins)
• Nuchal ligament
  
  • ​Cervical thickening of the supraspinous ligament, which runs along the spinous processes along the length of the vertebral column
  • Attaches superiorly to the external occiptal protuberance and inferiorly to spinous processes of the cervical vertebrae
  • Site of muscle attachment
• Thoracolumbar fascia
  
  • Dense sleeve of fascia in thoracic and lumbar regions
  • Site of muscle attachement
  • Surrounds intrinsic back muscles

Question 10

Extrinsic (superficial) muscles of the back

• Innervated by? Exception?
• What are the five extrinsic muscles?
• What are the two other muscles involved with respiration?
• Three muscles that compose the triangle of asucultation?

Answer 10

Extrinsic (superficial) muscles of the back

• Innervated by the ventral rami
• Exception: trapezius is innervated by CN XI (accessory nerve)
• Extrinsic muscles of the UE:
  
  • Trapezius
  • Latissimus dorsi
  • Levator scapulae
  • Rhomboid major
  • Rhomboid minor
• Other extrinsic musculature involved with respiration:
  
  • Serratus posterior superior - located deep to rhomboids
  • Serratus posterior inferior - located deep to latissimus dorsi
• Triangle of auscultation
  
  • ​Small region, free of overlying superficial muscles
  • Bounded by trapezius, latissimus dorsi, and the scapula
  • Lack of muscle in this area allows for more efficient use of a stethoscope to listen to sounds in the thoracic cavity

Question 11

Intrinsic (deep) muscles of the back

• Innervated by?
• Primary function?
• Superficial layer
  
  • What are the two muscles?
  • Origin? Insertion? Actions?
• Intermediate layer
  
  • One muscle divided into three
  • Origin? Insertion? Actions?
• Deep layer
  
  • One muscle divided into three
  • Origin? Insertion? Actions?

Answer 11

Intrinsic (deep) muscles of the back

• Innervated by dorsal rami
• Longitudinal columns of muscle, extending from the pelvis to the cranium
• Commonly injured
• Thoracic and lumbar portions are enclosed by the thoracolumbar fascia
• Functions:
  
  • Primary function is extension of the vertebral column
  • Secondary functions are lateral flexion and rotation

Superficial layer

• Splenius capitis and splenius cervicis (splenius = bandage)
  
  • Origin:
    
    • Nuchal ligament
    • Thoracic spinous processes
  • Insertion:
    
    • Mastoid process
    • Occipital bone (capitis)
    • Cervical transverse processes (cervicis)
  • Actions:
    
    • Bilateral contraction: extend neck
    • Unilateral contraction: lateral flexion and rotation of neck

Intermediate layer

• Erector spinae
  
  • ​3 columns from lateral to medial:
    
    • Iliocostalis
    • Longissimus
    • Spinalis
  • Origin:
    
    • Iliac crest
    • Sacrum
    • Lumbar spinous processes
  • Insertion:
    
    • Ilicostalis: ribs, transverse processes
    • Longissimus: transverse processes, mastoid process
    • Spinalis: spinous processes, occipital bone
  • Actions:
    
    • Bilateral contraction: extend vertebral column
    • Unilateral contraction: lateral flexion and rotation of vertebral column

Deep layer

• Transversospinalis
  
  • 3 parts from superficial to deep:
    
    • Semispinalis (cervical)
    • Multifidus (lumbar, think evil lumbar)
    • Rotatores (thoracic, think rotate - thoracic)
  • Origin/insertion:
    
    • Transverse processes to the spinous processes of more superior vertebrae (occupy the “gutter” between transverse and spinous processes)
  • Actions:
    
    • Bilateral contraction: stabilize vertebrae, extend vertebral column
    • Unilateral contraction: stabilize vertebrae, rotation to contralateral side