Atypical Cervical Vertebrae: C1/Atlas Flashcards Preview

Spinal Anatomy I - Exam 2 > Atypical Cervical Vertebrae: C1/Atlas > Flashcards

Flashcards in Atypical Cervical Vertebrae: C1/Atlas Deck (56):
1

What is the name of the first cervical vertebra?

Atlas

2

What features are lacking at C1?

- Vertebral body
- pedicles
- a spinous process
- intervertebral disc

3

What is thought to represent the pedicle at C1?

The anterior arch

4

What osseous modification is observed to the front of the anterior arch of C1?

The anterior tubercle

5

What muscle attaches to the anterior arch of C1?

Longus colli

6

What ligaments will attach to the anterior arch of C1?

- anterior longitudinal
- anterior Atlanta-occipital
- anterior atlanto-axial

7

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

the fovea dentis

8

What joint classifications are observed on the anterior arch of C1?

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

9

What is the contribution of the lateral mass to the circumference of C1?

forty percent - twenty percent for each lateral mass

10

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

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

11

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

backward, upward, medial (BUM)

12

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

synovial (diarthrosis) ellipsoidal joint

13

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

asymmetrical, slightly concave or flattened

14

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

backward, medial, downward (BMD)

15

What is the joint classification of the atlanto-axial zygapophysis?

synovial plane (diarthrosis arthrodia) joint

16

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

tubercle for the transverse atlantal ligament

17

What muscles attach to the lateral mass of C1?

- levator scapula
- splenius cervicis
- rectus capitis anterior

18

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

about forty percent

19

What part of C1 represents the spinous process?

posterior tubercle of the posterior arch

20

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

- male: about fifty millimeters
- female: about thirty-seven millimeters

21

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

- rectus capitis posterior minor
- ligamentum nuchae

22

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

- groove/sulcus for the vertebral artery
- arcuate rim

23

What attaches to the arcuate rim of C1?

the posterior atlanto-occipital ligament

24

What are the attachment sites of the posterior atlanto-occipital ligament?

- arcuate rim of the posterior arch of atlas
- superior articular process of the lateral mass of atlas
- posterior margin of the foramen magnum of the occipital bone

25

Ossification of the free margin of the posterior atlanto-occipital ligament results in which atypical bone classification?

accessory bone

26

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

about age 7 years old

27

Based on the amount of ossification of the anterior free margin of the posterior atlanto-occipital ligament what structures will form?

an incomplete ponticulus posticus or a complete ponticulus posticus

28

What are the attachment sites of the ponticulus posticus?

- arcuate rim of the posterior arch of atlas
- superior articular process of the lateral mass of atlas

29

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

Kimmerle's anomaly

30

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

arcuate foramen or retroarticular canal

31

Ponticulus posticus has been observed in what ethnic populations?

all ethnic populations studied thus far

32

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

1% - 4%

33

What is the gender bias now associated with ponticulus posticus?

female

34

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

- the incidence of a complete ponticulus posticus is about 15%
- the incidence of an incomplete ponticulus posticus may be as high as 41%

35

What is observed on the undersurface of the posterior arch of C1?

- inferior vertebral notch
- an attachment site for the posterior atlanto-axial ligament

36

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

fibrous (amphiarthrosis) syndesmosis joint

37

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

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

38

What is the general appearance of the transverse process of C1?

triangular

39

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

- costal element
- posterior tubercle
- true transverse process

40

What osseous parts of the transverse tubercle are absent at C1?

- anterior tubercle
- costotransverse bar

41

What muscles attach to the transverse process of C1?

- rectus capitis anterior
- rectus capitis lateralis
- middle scalene
- levator scapula
- splenius cervicis
- obliquus capitis superior
- obliquus capitis inferior
- intertransversarii

42

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

- rectus capitis posterior major
- rectus capitis posterior minor
- obliquus capitis inferior

43

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

myodural bridges

44

What are the lateral bridges of atlas connected to?

lateral mass and transverse process of atlas

45

What forms of the lateral bridges are observed in the population?

incomplete lateral bridges and complete lateral bridges

46

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

the retrotransverse foramen

47

What are the possible contents of the retrotransverse foramen?

- vertebral artery
- branch from the suboccipital nerve
- veins communicating with the venous sinuses of the neck

48

Which of the ponticles (bridges) of atlas is most numerous?

ponticulus posticus

49

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

lateral bridges

50

What is observed in the transverse foramen of C1?

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

51

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

- males: 78 millimeters
- females: 72 millimeters

52

Is there a gender difference for the distance from the posterior tubercle of the transverse process of C1 to the skin?

not a significant difference

53

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

a little over 30 millimeters for both male and female

54

What joint classifications are observed at C1?

- fibrous (amphiarthrosis) syndesmosis joint
- synovial (diarthrosis) ellipsoidal joint
- synovial pivot (diarthrosis trochoid) joint
- synovial plane (diarthrosis arthrodia) joint

55

How many synovial joint surfaces are observed at C1?

five

56

What synovial joint surfaces are observed at C1?

- two superior articular facets
- two inferior articular facets
- fovea dentis