7. Age at which the secondary curvatures of the spine develop:
8. Enumerate the contents of sacral canal
Anterior and posterior roots of the lumbar, sacral and coccygeal spinal nerves; filum terminale and fibrofatty material.
It also contains the lower part of the subarachnoid space down as far as the lower border of the 2nd sacral vertebra.
Anterior and posterior surfaces of the sacrum possess on each side four foramina for the passage of the anterior and posterior rami of the upper four sacral nerves.
Sacrum is usually wider in proportion to its length in the female than in the male.
Sacrum is tilted forward so that it forms an angle with the fifth lumbar vertebra, called the lumbosacral angle.
9. List the parts of intervertebral disc
· Annulus fibrosus (peripheral part) – Is composed of fibro-cartilage in which the collagen fibres are arranged in concentric layers.
· Nucleus pulposus (central part) – Is an ovoid mass of gelatinous material containing a large amount of water, a small number of collagen fibres, and a few cartilage cells.
10. List the joints of the atlanto-axial joint
· Median atlanto-axial joint: Between the odontoid process of the axis and the anterior arch of the atlas (Pivot).
· Lateral atlanto-axial joints: Inferior articular facet of the lateral mass of atlas and superior articular facet of the axis (Plane).
11. List the ligaments of the atlanto-axial joint
1. Apical ligament: (median-placed structure)
Connects the apex of the odontoid process to the anterior margin of the foramen magnum.
2. Alar ligaments:
Lie one on each side of the apical ligament
Connect the odontoid process to the medial sides of the occipital condyles
3. Cruciate ligament:
This ligament consists of a transverse part and a vertical part.
Transverse part
Is attached on each side to the inner aspect of the lateral mass of the atlas and
Binds the odontoid process to the anterior arch of the atlas.
Vertical part
Runs from the posterior surface of the body of the axis to the anterior margin of the foramen magnum.
4. Membrana tectoria:
This is an upward continuation of the posterior longitudinal ligament.
It is attached above to the occipital bone just within the foramen magnum.
It covers the posterior surface of the odontoid process and the apical, alar, and cruciate ligaments.
5. Capsular ligament:
12. List the movements at the atlanto-axial joint
Extensive rotation of the atlas and thus of the head on the axis (No movement).
13. List the movements at the atlanto-occipital joint
· Flexion, extension, and lateral flexion (Yes movement)
· No rotation is possible
14. What is sacral promontory?
Anterior and upper margins of the first sacral vertebra bulge forward as the posterior margin of the pelvic inlet