Atypical Cervical Vertebrae: C1/Atlas

Question 1

What muscle attaches to the anterior arch of C1?

Answer 1

Longus Colli

Question 2

What is the orientation of the superior articular facet of C1?

Answer 2

Backward, upward, medial (BUM)

Question 3

What is the orientation of the inferior articular facet of C1?

Answer 3

Backward, meidal, downward (BMD)

Question 4

What muscles attach to the lateral mass of C1?

Answer 4

Levator Scapula, splenius cervicis and rectus capitis anterior

Question 5

What is the distance from the posterior tubercle of the posterior arch to the skin in each gender?

Answer 5

Males: about 50mm
Females: about 37 mm

Question 6

What attaches to the posterior tubercle of the posterior arch of C1?

Answer 6

Rectus capitis posterior minor muscle and ligamentum nuchae

Question 7

What is the earliest age of development where ossification of the anterior free margin of the posterior atlanto-occipital ligament was observed?

Answer 7

About age 7 years old

Question 8

What names are given to the opening formed by the ponticulus posticus?

Answer 8

Arcuate foramen and retroarticular canal

Question 9

Ponticulus posticus has been observed in what ethnic populations?

Answer 9

All populations studied thus far

Question 10

What is the general range of incidence of ponticulus posticus in the populations studied?

Answer 10

1-41%

Question 11

What is the gender bias now associated with ponticulus posticus?

Answer 11

Female

Question 12

What muscles attach to the transverse process of C1?

Answer 12

Rectus capitis anterior, rectus capitis lateralis, middle scalene, levator scapula, splenius cervicis, obliquus capitis superior, obliquus capitis inferior and intertransversarii muscles

Question 13

What suboccipital muscles are known to have fascial projections attaching to the spinal dura?

Answer 13

Rectus capitis posterior minor, rectus capitis posterior major, obliquus capitis inferior

Question 14

What are the connections between suboccipital muscles and the spinal dura called?

Answer 14

myodural bridges

Question 15

What are the lateral bridges of atlas connected to?

Answer 15

The lateral mass and the transverse process of atlas

Question 16

What opening is identified when a complete lateral bridge is formed?

Answer 16

The retrotransverse foramen

Question 17

What are the possible contents of the retrotransverse foramen?

Answer 17

The vertebral artery, a branch from the suboccipital nerve and veins communicating with the venous sinuses of the neck

Question 18

Which of the ponticles (bridges) of atlas is only obersved in humans?

Answer 18

Lateral bridges

Question 19

What is observed in the transverse foramen of C1?

Answer 19

Vertebral artery, vertebral venous plexus, postganglionic sympathetic motor nerve fibers

Question 20

What is the gender variation for measurements of the transverse diameter of C1?

Answer 20

Males: 78mm; Females: 72mm

Question 21

What is the distance from the posterior tubercle of the transverse process of C1 to the skin for each gender?

Answer 21

A little over 30mm for both males/females

Question 22

How many synovial joint surfaces are observed at C1?

Answer 22

5

Question 23

What synovial joint surfaces are observed at C1?

Answer 23

Two superior articular facets, two inferior articular facets and the fovea dentis