4.4 the vertebral columnn

Question 1

The vertebral bodies of different segments possess different shapes and structures:
- Cervical (rounder)
- Thoracic (heart-shaped)
- Lumbar (oval/kidney-shaped)
• Most of the head rotation occurs at the levels of C1 – C2 (neck is the mobile portion of the spine which allows for flexion and extension, rotation and lateral flexion)
• Distinguished by the ______________ within the transverse processes

Answer 1

foramen transversarium

Question 2

ATLAS (C1)
The C1 vertebra (atlas) is a ring-like bone holding up head:
• Atlas has no ____________ (instead possessing a posterior tubercle)
• Course of vertebral artery: passes through the __________ (within the transverse process) → runs in groove on ___________ (along with C1 spinal nerve)

Joints
- Atlantooccipital: Superior facet of the atlas articulates with the ____________
• Nodding head up and down (flexion and extension)

• Atlantoaxial: Inferior facet of the atlas rotates on the ______________
  • Rotate head from side to side (lateral rotation)

*The craniovertebral joints are synovial joints (larger range of motion than other joints of vertebral column).

Answer 2

vertebral body or spinous process;

transverse foramen;

posterior arch;

occipital condyle;

articular facets of C2

Question 3

AXIS (C2) The C2 vertebra (axis) is the strongest cervical vertebra which serves as the point of articulation where the head turns on the neck (axis of rotation):
• _____________ projects superiorly (atlantoaxial joint)
• Vertebral artery: via transverse foramen

Answer 3

Dens (odontoid process/peg)

Question 4

What are the bones involved in the medial atlantoaxial joint (synovial pivot joint) ?

Answer 4

Anterior arch of atlas (C1) with dens of axis (C2) → allows for rotation of the head independent of the torso

Question 5

what are the bones involved in the lateral atlantoaxial joints (synovial plane joints)?

Answer 5

Inferior articular facets of atlas (C1) with superior articular facets of axis (C2) → forms 2 lateral joints

Question 6

what are the cruciate ligaments that Holds C1 onto C2 (prevents slippage of the head when it turns) → retains dens in contact with the atlas

Answer 6

• transverse ligament ( Across posterior aspect of dens (to small tubercles on lateral masses of the atlas))
• Superior longitudinal band (crus superius)
• Inferior longitudinal band (crus inferius)

Question 7

what are the longitudinal ligaments that prevents hyperextension and hyperflexion?

Answer 7

• Anterior longitudinal

- Posterior longitudinal

Question 8

what is the deep ligament that

• attaches to Lateral aspects of dens to tubercles on medial side of occipital condyle
• Prevents excessive rotation of head and holds skull to C2

Answer 8

Alar ligaments

Question 9

where does apical ligament attaches to

Answer 9

Tip of dens to anterior margin (basion) of foramen magnum

Question 10

tectorial membrane joins clivus to the body of C2. where does it attach to?

Answer 10

Basilar groove of occipital bone and dura mater to posterior surface of body of axis

Question 11

The remaining cervical vertebrae (C3 to C7) have small vertebral bodies for flexion of neck:
• C7 is known as the ______________ (most superior vertebra that is palpated in the neck)
• Large triangular vertebral foramen (through which spinal cord passes)
• C3 to C5 possess short _____________ (splits into two distally), while C6 and C7 have long spinous processes
• Possess narrow intervertebral foramina (higher risk of nerve root compression)

Answer 11

vertebra prominens;

bifid spinous processes

Question 12

what is the ligament that connects the spinous processes of adjacent vertebrae?

Answer 12

interspinous ligament

Question 13

Supraspinous ligament: Attaches to the ___________(continues as the ligamentum nuchae from C1 – C7)
• Ligamentum nuchae is the proximal attachment for the rhomboids and trapezius muscles

Answer 13

tips of the spinous processes

Question 14

Ligamentum flavum: Connects _____________ of adjacent vertebrae:
• Thickening of the ligamentum flavum can cause posterior compression of the spinal cord (anterior/lateral compression by intervertebral discs)

Answer 14

articular processes of laminae

Question 15

The vertebral column possesses a natural curvature which consists of lordosis and kyphosis:
• Thoracic and sacral curvatures (kyphosis) are primary curvatures (inborn), while the cervical and lumbar curvatures (lordosis) are secondary curvatures
• Secondary curvatures are accentuated by learned behaviours (e.g. support of head, upright posture)

Lordosis*: Anterior curvature of the spine (normal in the ____________ regions)

Kyphosis*” Posterior curvature of the spine (normal in the _________ regions)

Scoliosis:Abnormal lateral/rotational spinal curvature
*Excessive kyphosis and lordosis are abnormal.

Answer 15

cervical and lumbar;

thoracic and sacral

Question 16

which surface landmarks of the verebrae are important?

Answer 16

• C7: Prominent palpable spinous process in the neck (accentuated with anterior flexion of the head)
• T3: Level of the scapular spines
• T7: Inferior angles of the scapula
• L2: Midpoint of the vertical line drawn from the transpyloric plane (L1) and subcostal plane (L3)
• L4: Supracristal plane (horizontal plane across the highest points of the iliac crests)

Question 17

The vertebral artery supplies the posterior brain, spinal cord and lateral medulla:
• Arises from the ________________ and passes superiorly through the ______________-then through the foramen magnum
• Gives off several important branches (e.g. spinal arteries, posterior spinal arteries, posterior inferior cerebellar arteries)
• Left and right vertebral arteries unite at the lower border of the pons to form the ____________ (runs in the pontine basilar sulcus)
• Splits into the ___________________ at the upper border of pons

Answer 17

1st part of the subclavian artery (medial to scalenus anterior);

foramen transversarium of C1 – C6 ;

basilar artery;

terminal posterior cerebral arteries (PCA)

Question 18

The spinal cord develops from the lower part of the neural tube inferior to the medulla oblongata, and is surrounded by meninges and the vertebral column:
• Possesses an _______________ (deeper) and a posterior median sulcus

Answer 18

anterior median fissure

Question 19

The spinal cord gives rise to 31 pairs of spinal nerves (8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal):
• Tapers off at the level of ____________
• Remaining spinal nerves (L2 – Co) continue downwards and exit below respective vertebrae (cauda equina)
• Lumbar punctures are performed below the level of the conus medullaris (usually done around ____________) → CSF should be a clear fluid (xanthochromia → red/orange CSF indicates _____________)

*All the spinal nerves are mixed nerves (motor and sensory) except for C1 (only motor to the _____________ → no C1 dermatome).

Answer 19

L1/L2 (conus medullaris);

L3 – L4;

subarachnoid haemorrhage;

geniohyoid muscle

Question 20

SPINAL MENINGES The dura mater in the spinal cord only possesses one layer (instead of the endosteal and meningeal layers in the cranial dura):
• Dura is much thicker in the spinal cord and does not have any ____________
• __________ is larger (allowing for more drainage of CSF)
• Possesses ______________ (extensions of the pia mater into the dura) which separate the anterior and posterior components of spinal cord and provides stability to the top of the nerve roots

Answer 20

venous sinuses;

Epidural space ;

denticulate ligaments