Atypical Cervical Vertebrae: C1/Atlas

Question 1

What is the name of the first cervical vertebrae?

Answer 1

atlas

Question 2

What features are lacking at C1?

Answer 2

vertebral body,pedicles, a spinous process and the intervertebral disc

Question 3

What muscle attaches to the anterior arch of C1?

Answer 3

longus colli

Question 4

What ligaments will attach to the anterior arach of C1?

Answer 4

the anterior longitudinal ligament, anterior atlanto-occipital and anterior atlanto-axial ligaments

Question 5

What is observed on the back of the anterior arch of C1?

Answer 5

the fovea dentis

Question 6

What joint classifications are observed on the anterior arch C1?

Answer 6

fibrous (amphiarthrosis) syndesmosis joint and synovial pivot (diarthrosis trochoid) joint

Question 7

What is the morphology of the superior articular facet?

Answer 7

they are elipitcal, closer together in front and often demonstrate an elevation subdividing the facet surface into two seperate surfaces

Question 8

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

Answer 8

backward, upward and medial (BUM)

Question 9

What is the joint classificaiton of the atlanto-occipital zygapophysis?

Answer 9

synovial (diarthrosis) ellipsoidal joint

Question 10

What are the morphological characteristics of the inferior articular facet of C1?

Answer 10

asymmetrical, slightly concave or flattened

Question 11

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

Answer 11

backward, medial, and downward (BMD)

Question 12

What is the name of the rounded elevation on the medial aspect of the lateral mass of C1?

Answer 12

tubercle for the transverse atlantal ligament

Question 13

What muscles attach to the lateral mass of C1?

Answer 13

levator scapula, splenius cervicis, and rectus capitis anterior

Question 14

What is the contribution of the posterior arch to the circumference of C1?

Answer 14

about forty percent

Question 15

What part of C1 represents the spinous process?

Answer 15

posterior tubercle of the posterior arch

Question 16

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

Answer 16

male: about fifty millimeters; females: about thirty-seven millimeters

Question 17

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

Answer 17

rectus capitis posterior minor muscle and ligamentum nuchae

Question 18

What superior surface modifications of the posterior arch of C1 are present?

Answer 18

groove/sulcus for the vertebral artery and arcuate rim

Question 19

What attaches to the arcuate rim of C1?

Answer 19

the posteior atlanto-occiptal ligament

Question 20

Ossification of the free margin of the posteior atlanto-occipital ligament results in which atypical bone classifiction?

Answer 20

accessory bone

Question 21

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

Answer 21

about age seven years old

Question 22

What may be formed by ossification of the anterior free margin of the posterior atlanto-occipital ligament?

Answer 22

a partial ponticulus posticus or a complete ponticulus posticus

Question 23

What other name may be used to identify a ponticulus posticus?

Answer 23

Kimmerle’s anomaly

Question 24

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

Answer 24

arcuate foramen or retroarticular canal

Question 25

Ponticulus posticus has observed in what ethnic populations?

Answer 25

all ethnic populations studied thus far

Question 26

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

Answer 26

1% - 41%

Question 27

What is the gender bias now associated with ponticulus posticus?

Answer 27

female

Question 28

What is the incidence of a complete ponticulus ponticus versus an incomplete ponticulus posticus?

Answer 28

the incidence of a complete ponticulus posticus is about fifty percent; the incidence of an incomplete ponticulus posticus may be as high as forty-one percent?

Question 29

What joint classification(s) may be observed on the posterior arch of C1?

Answer 29

fibrous (amphiarthrosis) syndesmosis joint

Question 30

What is the location of the "zygapophysis" realtive to the atlanto-occipital and atlanto-axial intervertebral foramina?

Answer 30

it forms part of the anterior boundary of the intervertebral foramen in both cases

Question 31

What are the osseous parts of the transverse process of C1?

Answer 31

costal element, posterior tubercle, true transverse process

Question 32

What osseous parts of the transverse process of C1 are absent?

Answer 32

anterior tubercle and costotransverse bar

Question 33

What muscles attach to the transverse process of C1?

Answer 33

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

Question 34

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

Answer 34

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

Question 35

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

Answer 35

myodural bridges

Question 36

What are the lateral bridges of atlas connected to?

Answer 36

the lateral mass and the transverse process of atlas

Question 37

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

Answer 37

the retrotransverse foramen

Question 38

What are the possible conents of the retrotransverse foramen?

Answer 38

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

Question 39

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

Answer 39

lateral bridges

Question 40

What is observed in the transverse foramen of C1?

Answer 40

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

Question 41

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

Answer 41

males: 78 mm females: 72 mm

Question 42

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

Answer 42

a little over 30 mm for both genders

Question 43

What joint classifications are observed at C1?

Answer 43

fibrous (amphiarthrosis) syndesmosis joint, synovial (diarthosis) ellipsoidal joint, synovial pivot (diarthrosis trochoid) joint and synovial plane (diarthrosis arthodia) joint

Question 44

How many synovial joint surfaces are observed at C1?

Answer 44

five

Question 45

What synovial joint surfaces are aboserved at C1?

Answer 45

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