Back & Vertebral Column

What are some of the main functions of the vertebral column?

• Protect the spinal cord

• Structure support (i.e. posture)

• Pathway for neurons to communicate with the spinal cord (provision of entry & exit points for nerves)

What are the implications of fused vertebra in the sacrum & coccyx?

Allows for collective movement

What are the implications of stacked vertebra in the cervical, thoracic, & lumbar regions of the vertebral column?

Allows for different movements to be produced;

• Cervical vertebrae → twisting of the neck

• Thoracic vertebrae → limited movement (more bones/ribs attached → more restriction)

What does the term kyphosis/kyphotic refer to?

Primary curvatures of the vertebral column

• Primary ‘C’ - shapes curvature seen in foetus

Why is tummy time important for babies?

Trains their tissues to change the kyphotic position of the vertebral column to a lordotic position

What does the term lordotic refer to?

Secondary curvatures of the vertebral column

• Found in the cervical & lumbar regions

• Allow us to maintain our posture for a long period of time

What is the difference between the terms ‘atypical’ & ‘abnormal’

• Atypical: different from what is most common/expected

• Abnormal: something which is not necessarily right and may cause impaired functioning

What does the following image display an example of, & how might this occur?

• Excessive lordosis: increased secondary curvature in the lumbar region

• Possible causes:

  • Differences in pelvic posture

  • Pregnancy → changes in weight-bearing across the body

What does the following image display an example of, & how might this occur?

• Excessive kyphosis: increased primary curvature in the thoracic region

• Possible causes:

  • Excessive weight-bearing

  • Being nervous (emotional state)

  • Puberty

What does the following image display an example of, & how might this occur? What are some implications of severity of this condition?

• Scoliosis: abnormal side-to-side curvature of the vertebral column

• Possible cause: differences in repeated postural positions (e.g. curvature of the spine in a violin player due to repeated posture in which a violin was held)

• Severe scoliosis may affect the viscera → may need to be corrected by surgery

Label the following diagram of sections of lumbar vertebrae

What are the roles of the vertebral body?

• Weight bearing

• Superior & inferior articulation

• Anchorage of articular discs to the vertebrae via an epiphyseal ring

What are the roles of the vertebral arch?

• Formation of the vertebral foramen = passageway for the spinal cord

• Protection of the spinal cord

What are the roles of the spinous & transverse processes?

• Levers for muscle & ligamentous attachment

  • Because we need to be able to support joints, connect tissues, & move these regions

What are the roles of articular processes & articular facets?

• Project superiorly & inferiorly → superior & inferior articulations

  • Project with articular facets (cyan): smoothened areas which allow for gliding movements

    • The directions facets are facing guides the movements that different regions of the vertebral column can achieve

• Controls direction & extent of movement (unlike the vertebral body)

What is a distinct feature of cervical vertebrae?

‘Eyes’ in the vertebral column = site for vascular structures to pass through

What are two distinct features of thoracic vertebrae?

• Huge inferior-projecting spinal processes

• More articular surfaces than cervical & lumbar (accidentally wrote thoracic on diagram) → sites for rib attachment

What is a distinct feature of lumbar vertebrae?

Large vertebral body for weight-bearing

Why are the superior & inferior vertebral notches labelled as such, & not as foramen?

Formen produce continuous complete holes (e.g. vertebral canal), whereas notches produces incomplete holes (intervertebral foramen - idk why they are called foramen)

Label the following diagram

What are intervertebral foramen?

Holes in the vertebral column which are pathways for nerve projections of the spinal cord

What are the 3 intervertebral contents?

• Spinal nerve roots

• Dorsal root ganglia

• Vessels

What are the boundaries of the intervertebral foramen? Label them in this diagram

• Inferior vertebral notch

• Superior vertebral notch

• Articular process

• Vertebral disc

• *Articular facet isn’t a boundary of the intervertebral foramen

What is an intervertebral joint?

The vertebral disc and its associated vertebral body

• NOT all the joints associated from one vertebra to the next

What type of joint is an intervertebral joint?

• Symphysis; secondary cartilaginous joint

• Brings force down & disperses weight onto the vertebra

Label the following diagram

State the two components of the vertebral disc

• Annulus fibrosus

• Nucleus pulposus

Describe the annulus fibrosus

• Concentric lamellae/angulations of collagen fibres

• Permits movement in all directions

• Resists excessive rotation

Describe the nucleus pulposus

• Gelatinous consistency

• Shock absorber → disperses compressive forces

• Deforms but is not compressible

• Ability to hold water (why we are 1-2 cm taller in the morning - water retained in the nucleus pulposus when we sleep)

What are zygapophyseal joints?

Plane synovial joints relating to gliding movements

• Movement depends on the orientation of the articular surfaces involved

• Superior & inferior processes have ‘facets’/articular surfaces

What type of movement is permitted by the thoracic zygapophyseal joints?

• Rotation & side-bending

• Movement in the coronal plane

• Range of motion is restricted by the ribs

What type of movement is permitted by the lumbar zygapophyseal joints?

• Flexion & extension

• Movement in the sagittal plane

What do the posterior longitudinal ligament & anterior longitudinal ligament attach to?

The vertebral body

What properties does the ligamentum flavum have that other vertebral column ligaments don’t have, & what is the implication of this property

• More elastin than other vertebral column ligaments

  • Permits more stretch & movement

• Not as continuous as interspinous & supraspinous ligaments

  • Extends from one vertebra to the next & then stops

Label the following diagram of the major vertebral column ligaments

What are the extrinsic back muscles?

Attach to & act on the upper limb

Describe properties of extrinsic back muscles & provide some examples

• Trapezoid & rhomboid shapes

• 'Major’ (large) & ‘minor’ (small)

• Examples:

  • Latissimus Dorsi (broadest back)

  • Levator Scapulae (elevate scapula)

Label the following diagram of extrinsic back muscles

What are intrinsic back muscles?

Primarily attach to & act on the back (localised function)

What are the prime movers of the back, & what plane do they permit movement in?

• Erector spinae → movement primarily in the sagittal plane

  • Concentrically extend the trunk

  • Eccentrically flex the trunk

  • Commonly implicated w/ postural issues when they become tired & fatigued from constantly being worked

Describe the structure, location & function of transversospinalis muscles

• Structure: group of short muscles which extend from one vertebra to the next

• Location: deep to the erector spinae, localised to the vertebral column

• Function:

  • Control of ‘fine’ movements @ vertebral segments

What are multifidus muscles?

Thicker transversospinalis muscles attached to the lumbar region of the vertebral column

• Allow for finer control of movement

• Important in rehabilitation; improve smaller ‘segmental’ movements

  • Injuries may arise if the multifidus is not supporting the spine at a local, controlled level