General Anatomy (vertebral Column)

Question 1

What is the function of the VC?

Answer 1

1. Protection of the spinal cord + spinal nerves.
2. Supports weight of the body (sup to pelvis)
3. Provides partly rigid/flexible axis for body + pivot for head
4. Important for posture + locomotion

Question 2

What is primary curvature?

Answer 2

Primary curvature: (maintained by the thickness of anterior & posterior parts vertebrae)
• Thoracic (concave anteriorly)
• Sacral or pelvic (concave anteriorly-less in
female)

Question 3

What is secondary curvature?

Answer 3

Secondary curvature: (maintained by the thickness of anterior & posterior parts of IV disc)
- Cervical (convex anteriorly): 3-9 months-raise the head in prone position
- Lumbar (convex anteriorly-more in female): 12-18 months-standing & walking
- Secondary curvatures begin to appear during the late foetal period but do not become obvious until infancy.

Question 4

What are the three abnormal curvature?

Answer 4

• Kyphosis: Exaggeration of thoracic curvature
• Lordosis: Exaggeration of lumbar curvature
• Scoliosis: lateral curvature

Question 5

What are the three basic components of a typical vertebra?

Answer 5

• vertebral body
• vertebral arch
• vertebral foramen

Question 6

What does the vertebral arch have?

Answer 6

• Pedicles (2)
• Laminae (2)
• Spinous process (1)
• Transverse processes (2)
• Superior articular processes (2)
• Inferior articular processes (2)

Question 7

What are the superior and inferior surfaces of vertebral body covered in?

Answer 7

Hyaline cartilage

Question 8

What makes the intervertebral foramen?

Answer 8

Superior vertebral notch combined with the inferior vertebral notch of upper vertebra

Question 9

What passes through the intervertebral foramen?

Answer 9

Spinal nerves

Question 10

What are the characteristic features about typical cervical vertebra (C-3 to C-6)?

Answer 10

• Foramen transversarium in transverse process; Foramen transversarium of C6- C1 transmit vertebral vessels (C7-1: vertebral vein only).
• Spinous processes are bifid and short (with the exception of C7).
• Small body (C1 has no body)
• Large & triangular vertebral foramen

Question 11

What are the three components of Atypical cervical vertebrae?

Answer 11

Atlas (C1), Axis (C2) and vertebral prominens (C7)

Question 12

What is the Atlas (C1)?

Answer 12

• It has no body & no spine but simply the anterior
and posterior arches.
• The posterior arch is longer and grooved over by the vertebral artery.
• The anterior arch is short & thicker.

Question 13

What is the axis (C2)?

Answer 13

• It has the odontoid process or dens extending upwards from its body (originally it is the body of C1).
• This dens forms the middle atlanto-axial joint (pivot type) with the anterior arch of the atlas, makes the rotatory movement of head (‘NO’ movement).

Question 14

What is the vertebral prominence (C7)?

Answer 14

Spinous process is long and not bifid (can be palpated at
root of the neck), large transverse process.

Question 15

What are the characteristics of typical thoracic vertebra (T2-T9)?

Answer 15

• Costal facets on body & transverse process for
articulation with ribs
• Body is medium, heart-shaped
• Vertebral foramen small, circular
• Spines are long & slope postero-inferiorly.
Articulation with the ribs (costovertebral joints):
➢ Ribs 2-9 articulate to the body & transverse process of the corresponding same as well as the body of the upper vertebra.

Question 16

What is the greatest degree of rotation in the middle 4 thoracic vertebrae?

Answer 16

• happens between superior and inferior articular processes (Zygapophysial joint)
• the articular processes extend nearly vertical with reciprocal arch (concave and convex)
• their articular facets are centered in the IV disc

Question 17

What are the characteristics of Atypical thoracic vertebrae T1, T10, T11, T12?

Answer 17

• Superior facet is complete (not demi) facet.
• Inferiorly there is demi facet.
• Spinous process almost horizontal,
that may be nearly as prominent as that of the vertebra prominens (C7).

➢ Single (superior) facet is complete; & no inferior facet.

Question 18

What does the characteristics of the 11th and 12th thoracic?

Answer 18

• Superior facet is complete
• no inferior facet
• no facet on transverse
- 12th one looks like lumbar vertebra.
- Inferior half is lumbar in character.
- Inferior articular surface directed laterally that permit only flexion & extension.
- Consequently, vertebra T12 is subject to transitional stresses that cause it to be the most commonly fractured one.

Question 19

What is the characteristics of the lumbar vertebra?

Answer 19

• Massive kidney-shaped bodies
• Vertebral foramina is large &
triangular
• Spinous processes are short, thick, &
quadrangular.
• Transverse process is long & slender, accessory process present on posterior aspect of its base.
• Mammillary process on the superior articular process.

Question 20

What are the characteristics of L-5 is atypical?

Answer 20

• Massive transverse process
• Largest body
• Gap between inferior articular
processes is larger than the gap
between superior articular processes.

Question 21

What are the characteristics of the sacrum?

Answer 21

• 5 vertebral vertebrae fused into a wedge-shaped sacrum (at age 30).
• Wider & shorter in female
• Transmits the weight of the body to
the pelvic girdle via sacroiliac joints.
• Apex & base
• Ala is upper surface of lateral mass.
• Pelvic surface (smooth & concave)
• Dorsal surface (rough & convex)
Cornu
• Sacral promontory (anterior edge of S1 body) is more prominent in male than in female, obstetric landmark in women.
• Sacral foramina transmit anterior & posterior rami of sacral nerves.

Question 22

What are dorsal surface of sacrum and coccyx?

Answer 22

• Three sacral crests are the fusions of spines, articular processes & tip of transverse processes
• Sacral hiatus is lower end of sacral canal & is due to lacking laminae & spinous processes of S5 (sometimes S4 also).
• Sacral hiatus transmits the filum terminale of spinal cord.
• Coccyx is fused 4 segments.

➢ Sacral hiatus is a clinically important as it allows needle- access to the inferior vertebral canal for caudal anaesthesia.

Question 23

What is the intervertebral joint?

Answer 23

Symphysial joint between two vertebral bodies; Intervertebral disc is a fibrocartilage disc (lumbosacral is intervertebral joint).

Question 24

What is Zygapophysial or facet joints?

Answer 24

Synovial joints of the vertebral arches

Question 25

What are costovertebral joints?

Answer 25

Synovial joints with the ribs

Question 26

What is atlanto-axial joints?

Answer 26

Synovial joints between dens od 2nd cervical & anterior arch of 1st cervical; rotation (‘NO’-movement).

Question 27

What is the atlanto-occipital joint?

Answer 27

Synovial joints with occipital bone; nodding or flexion-extension of the head (‘YES’-movement).

Question 28

What is the sacroiliac joint?

Answer 28

joints with hip bone, synovial joints

Question 29

What is the movement of vertebral column?

Answer 29

➢ Flexion: Forward bending
➢ Extension: Straightening, backward bending ➢ Lateral bending (lateral flexion)
➢ Rotation: Mostly in thoracic region
➢ Circumduction

Question 30

Why is the vertebral column flexible?

Answer 30

because it consists of many small bones (vertebrae), that are separated by resilient IV discs. The 25 (cervical, thoracic, lumbar, and first sacral) vertebrae articulate at synovial zygapophysial (facet) joints, which facilitate and control the vertebral column’s flexibility

Question 31

What are the ligaments of vertebral column?

Answer 31

• Nuchal ligament
• Longitudinal ligaments (antr. & post.)
• Tectorial membrane
• Ligamenta flava
• Supraspinous ligament
• Interspinous ligaments
• Vertebral joint ligaments

Question 32

What is the anterior longitudinal ligament?

Answer 32

• It is a strong, broad fibrous band that covers & connects the anterolateral aspects of the vertebral bodies & IV discs.
• This ligament extends longitudinally from the pelvic surface of the sacrum to the anterior tubercle of vertebra C1 and the occipital bone anterior to the foramen magnum.
• Its superiormost parts are the anterior atlanto-axial and atlanto-occipital ligaments.
• This ligament prevents hyperextension of the vertebral column, maintaining stability of the joints between the vertebral bodies.
• The anterior longitudinal ligament is the only ligament that limits extension.

Question 33

What is the posterior longitudinal ligament?

Answer 33

• The is a much narrower, somewhat weaker band.
• It runs within the vertebral canal from C2 to the sacrum along the posterior aspect of
the vertebral bodies.
• It is attached mainly to the IV discs and less so to the posterior aspects of the vertebral
bodies, often bridging fat and vessels between the ligament and the bony surface.
• This ligament weakly resists hyperflexion of the vertebral column and helps prevent or
redirect posterior herniation of the nucleus pulposus.
• It is well provided with nociceptive (pain) nerve endings.
• Tectorial membrane is the strong superior continuation of the posterior longitudinal ligament from C2 & passes posteriorly over the median atlanto-axial joint and its ligaments.
It extends through foramen magnum to attach
to the internal surface of occipital bone.

Question 34

What is the Nuchal ligament?

Answer 34

• This ligament is the strong, broad & thickened fibroelastic tissue.
• It extends as a median band from the external occipital protuberance and posterior border of the foramen magnum to the spinous processes of the cervical vertebrae.
• Nuchal ligament provides attachment for muscles.

Question 35

What is the ligamenta flava?

Answer 35

• These ligaments extend almost vertically from the lamina above to the lamina below.

Question 36

What are some other ligaments?

Answer 36

• Interspinous ligaments is thin & connect
adjoining spinous processes.
• Supraspinous ligaments is a cord-like band
that connects the tips of the spinous processes from C7 to the sacrum.
• Intertransverse ligaments connect adjacent
transverse processes.

Question 37

What are the atlantoaxial joint?

Answer 37

3 atlanto-axial articulations, two (right and left) lateral atlanto- axial joints (between the facets of the lateral masses of C1 and C2-Gliding synovial) & one median atlanto-axial joint (between the dens of C2 and the anterior arch of the atlas-Pivot synovial type).

Question 38

What are the atlantoaxial ligaments?

Answer 38

• Cruciate ligament of AAJ: -
transverse ligament of C1 & longitudinal band from C2-C1 to foramen magnum (FM) margin
• Alar ligaments from the sides of the dens to FM margin.
• Apical ligament from the apex of dens FM margin

Question 39

What are the two parts of the intervertebral disc?

Answer 39

• Nucleus pulposus (inner jelly-like proteoglycan mass) can imbibe water & increase the thickness.
• Annulus fibrosus (outer fibrous tissue) is stronger & thicker anteriorly than in posteriorly.

Question 40

What is the function of the intervertebral disc?

Answer 40

• Bind the body of vertebrae strongly.
• Provide shock absorption.
• Allow limited movements.

Question 41

What is disc herniation?

Answer 41

• Excess tension of annulus fibrosus→ fibers torn (mostly posterolateral region) →herniation (prolapse) of nucleus pulposus→compression of nerve root
• Old age-related atrophy→rupture of annulus fibrosus & herniation of the nucleus pulposus.
• Compression of spinal nerve causing back pain or pain down the length of the leg.
• 95% herniation occur at L4/L5 or L5/S1.

Question 42

Fracture?

Question 43

What is the blood supply in the neck region?

Answer 43

Vertebrae are supplied by the branches of vertebral and ascending
cervical arteries.

Question 44

What is the blood supply in the trunk?

Answer 44

The segmental arteries are present at all levels of the vertebral column. These are:
• Posterior intercostal arteries in the thoracic region
• Subcostal and lumbar arteries in the abdomen
• Iliolumbar and lateral and medial sacral arteries
in the pelvis

Question 45

What is the venous drainage system?

Answer 45

➢ Spinal veins form venous plexuses along the vertebral column, both inside and outside the vertebral canal.
➢ These plexuses are internal vertebral venous plexuses and external vertebral venous plexuses.
➢ These venous plexus communicate with vertebral veins of the neck and segmental veins of the trunk (intercostal, lumbar, and sacral).

Question 46

What do the basivertebral veins do?

Answer 46

They emerge from foramina on the surfaces of the vertebral bodies (mostly the posterior aspect) and drain into the internal vertebral venous plexuses, also into anterior external plexus.

Question 47

What are the parts of a vertebral column?

Answer 47

Consist of 33 vertebrae.
Arranged in five regions from superior to inferior.
1. 7 Cervical (C1 – C7)
2. 12 Thoracic (T1 – T12)
3. 5 Lumbar (L1 – L5)
4. 5 Sacral vertebrae (sacrum)
5. 4 Coccygeal vertebrae (coccyx)

➢ The vertebrae gradually become larger as the column descends up to sacrum.
➢ A typical vertebra consists of a vertebral body, a
vertebral arch, and seven processes.