Vertebral Column and Intrinsic Back Muscles

Question 1

Functions of the vertebral column

Answer 1

Support for head and rest of body
Movement
Protection of spinal cord

Question 2

Features of cervical vertibrae?

Answer 2

7
Small
Relatively mobile
Most susceptible to dislocation

Question 3

Features of thoracic vertebrae

Answer 3

12
Articulate with ribs
Long processes for muscle attachment

Question 4

Features of lumbar vertebrae

Answer 4

5
Largest body
Susceptible to herniated IVDs

Question 5

Features of Sacrum

Answer 5

5 fused
Articulates with hip bones

Question 6

2 parts of a typical vertebra

Answer 6

Vertebral body
- transfers weight
- IVDs between
Vertebral arch
- forms vertebral foramen which surrounds and protects spinal cord

Question 7

Draw and label different parts of a typical vertebra

Answer 7

Pedicle - foot of arch
Transverse process - muscle/ ligament attachement (ribs in T)
Lamina - lateral and posterior part of arch (connect transverse process and spinal process)
Spinous process - muscle/ ligament attachment
Superior/ inferior articular processes - form joints between next vertebrae
Superior/ inferior vertebral notches - forms intervertebral foramen (nerves come out of)

Question 8

What level does the spinal cord end? Cliinical relevance?

Answer 8

Around L1/L2 - spinal nerves descend to exit, forming the cauda equina
Spinal tap below this level to reduce risk of hitting spinal cord

Question 9

How many cervical spinal nerves are there?

Answer 9

8

Question 10

Movements of vertebral column

Answer 10

Cervical = most mobile
Thoracic = least mobile for flexion/ extension/ lateral bending
Lumbar = least rotation

Question 11

What are the two different types of vertebral joints?
How many joints does a typical vertebra form?

Answer 11

Zyapophyseal (facet) joints - synovial, plane (between superior and articular)
Symphysis (intervertebral discs) - secondary cartilaginous joints between vertebral body

Forms 6: 4x zyapophyseal and 2x symphysis

Question 12

Structure and function of IVDs:

Answer 12

Structure:
- Annulus fibrous: fibrous sheath on outer surface (collagen layers in rings) and fibrocartilage inner zone. High tensile strength against pulling forces
- Nucleus pulposus: gelatinous structure (80-85% water), high resistance, can loose and gain water due to external pressure

Function:
- Stability and flexibility
- Pressure regulation
- Water-cushion function - shock absorber

Question 13

What is a slipped disc?

Answer 13

Prolapse of IVD
Tear in annulus fibrosus - nucleus pulposus can protude
- Can impinge on spinal cord or nerves

Question 14

What are C1 and C2 called? Why are they different?

Answer 14

C1 = Atlas, no body
C2 = Axis, odontoid (upright) process (dens)
No IVD between the 2 of them

Question 15

What joins C1 to the base of skull?

Answer 15

Atlanto-occipital joint
- Synovial joint
- Nodding of head joint

Question 16

What joint joins C1 to C2?

Answer 16

Atlanto-axial joint
- Synovial pivot
- Shaking of head

Question 17

What are the 3 functions of ligaments in the MSK?

Answer 17

Connect bone to bone
Provides support for joints
Restricts movement at joints

Question 18

What Ligaments are found in the spine?

Answer 18

Anterior logitudinal ligament
Posterior logitudinal ligament
Supraspinous and nuchal ligament
Ligamentum flavum
Interspinous/ intertransverse ligaments

Question 19

Where is the anterior longitudinal ligment?
What is its function?

Answer 19

Runs from base of skull to anterior surface of sacrum, attached to anterior surface of vertebral bodies and IVDs

Prevents hyperextension

Question 20

Where is the posterior longitudinal ligment?
What is its function?

Answer 20

Attaches C2 to sacrum, attached to posterior surface of vertebral bodies and IVDs, runs down the vertebral canal and lines anterior surface of vertebral canal
Weakly resists hyperflexion - not as strong as anterior

Question 21

Where are the supraspinous ligaments?

Answer 21

From C7 to sacrum
Connects tips of spinous processes
Cord like

Question 22

Where is the nuchal ligament?
What is its function?

Answer 22

Strong fibroelastic tissue from base of skull to C7
Supports head on neck and provides attachment for muscles

Question 23

What are the three ligaments between vertebrae?

Answer 23

Ligamenta Flava
- Pass between laminae
- Form part of posterior wall of vertebral canal
- Resist separation of verts during flexion
Intraspinous ligaments
- Between spinous processes
- Resists separation during flexion
Intertransverse
- Between transverse processes

Question 24

What do the intrinsic back muscles act on?

Answer 24

Directly on spine

Question 25

What are all the intrinsic muscle supplied by?

Answer 25

Posterior rami of spinal nerves

Question 26

Function of intrinsic muscles?

Answer 26

Maintain posture and control movement of vertebrae

Question 27

3 layers of intrinsic muscles

Answer 27

Superficial
Intermediate
Deep

Question 28

Function of the thoracolumbar fascia:

Answer 28

• Covers deep muscles of back
• Critical to organisation and integrity of region
• Latissimus dorsi and trapezius attached to it

Question 29

What muscles are found in the superficial layer? Where do they originate, insert and what are their actions?

Answer 29

Splenous muscles: splenius capitis and splenius cervicis

Origin - spinous processes, bottom of nuchal ligament

Insert:
Capitis: base of skull, mastoid process
Cervicis: transverse processes C1-3

Action:
- Bilateral: extends neck
- Unilateral: rotate head to one side (turn face to same side as muscle)

Question 30

What are the muscles in the intermediate layer?
What are the origins and insertions?
What is the general functions?

Answer 30

Erector spinae muscles: consists of 2 columns
- Iliocostalis, longissimus, spinalis

Common origins: broad tendon attached to sacrum, spinous processes of L and lower T verts, iliac crest

Insertions:
Iliocostalis: insets angles of ribs and C transverse process
Longissimus: inserts T and C transverse processes and mastoid processses
Spinalis: inserts T spinous processes and skull

Question 31

What muscle are in the deep layer?

Answer 31

Transversospinalis - fill the groove between spinous and transverse processes, semispinalis, multifidus, rotatores, cross multiple vertebrae, extend and rotate

Levatores costarum - lif up ribs up to transverse procesess
Interspinales and intertransversarii - connect spinous processes and transverse processes, only cross one vertebra