WEEK 1 - ATLAS & AXIS

Question 1

Atlas (Variation)

Answer 1

No body (large foramen)
Large articular facets.
No spinous process.

Question 1

Axis (Variation)

Answer 1

Odontoid process (dens)

Question 2

Atlas (Functional Significance of Variation)

Answer 2

No body: not needed for weight bearing, adds mobility, enables larger foramen, no IVD.
Large Articular Facets: Weight bearing of skull.
No spinous process: No muscle attachment, allows posterior arch allows greater surface area, allows spinal cord enlargement.

Question 3

Axis (Functional Significance of Variation)

Answer 3

Dens: Forms articulation with Atlas to allow rotation.

Question 4

Atlanto-Occipital Joint - Articular Surfaces

Answer 4

Occipital condyles of skull
Superior articular facets

Question 5

Atlanto-Occipital Joint

Answer 5

Histological Classification: Synovial.
Functional Classification: Condyloid.
Movements Possible: Freely mobile, predominantly flexion and extension.

Question 6

Atlanto-Axial Joint - Articular Surfaces

Answer 6

Anterior arch of atlas.
Odontoid process (dens).

Question 7

Atlanto-Axial Joint

Answer 7

Histological Classification: Synovial.
Functional Classification: Pivot.
Movements Possible: Rotation along transverse plane.