Atlanto-Axial Joint Flashcards Preview

Spinal Anatomy I - Exam 3 > Atlanto-Axial Joint > Flashcards

Flashcards in Atlanto-Axial Joint Deck (55):
1

What are the classifications of the atlanto-axial joint?

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

2

Which atlanto-axial joint is identified as a synovial pivot (diarthrosis trochoid)?

the median atlanto-axial joint

3

Which atlanto-axial joint is identified as a synovial plane (diarthrosis arthrodia)?

the lateral atlanto-axial joint

4

Which atlanto-axial joint is identified as a fibrous (amphiarthrosis) syndesmosis?

any non-capsular lig. typically forms a joint with this classification

5

What are names given to the synovial joint spaces of the median atlanto-axial joint?

- anterior bursa
- posterior bursa

6

What are the joint surfaces of the median atlanto-axial joint at the anterior bursa?

- the fovea dentis of C1
- facet for fovea dentis of C2

7

What are the joint surfaces of the median atlanto-axial joint at the posterior bursa?

- the groove for the transverse atlantal lig. of C2
- transverse atlantal lig.

8

Perpendicular ligamentous extensions from the transverse atlantal lig. will form what lig.?

the vertical crus lig.

9

What are the parts of the vertical crus lig.?

- superior crus lig.
- inferior crus lig.

10

What are the attachment sites of the superior crus lig.?

- upper margin of the transverse atlantal lig.
- anterior margin of the foramen magnum

11

What are the attachment sites of the inferior crus lig.?

- lower margin of the transverse atlantal lig.
- posterior surface of the vertebral body of C2

12

What part of the vertical crus lig. may be absent?

inferior crus lig.

13

What lig. is formed by the transverse atlantal lig. and its perpendicular extension?

cruciate lig. or cruciform lig.

14

What are the attachment sites of the transverse atlantal lig.?

tubercles for the transverse atlantal lig. on the lateral mass of C1

15

Why is the transverse atlantal lig. not a typical lig.?

- it does not attach 2 or more bones together
- it attaches parts of the same vertebra

16

What histological feature is present on the anterior surface of the transverse atlantal lig.?

fibrocartilage at the surface of the lig. articulating with C2

17

What is the function of the transverse atlantal lig.?

it is the primary stabilizer of the atlanto-axial joint restricting the distance of C2 from the anterior arch of C1

18

Where is Barkow's lig./lig. of Barkow observed?

just above the anterior arch of C1 and in front of the dens near its tip

19

What are the attaching sites of Barkow's lig.?

to the occipital condyles just in front of the alar attachment site

20

What is the function of Barkow's lig.?

it may restrict extension (hyperextension or dorsi-flexion) of the atlanto-occipital joint

21

Where is the transverse occipital lig. observed?

posterior to the tip of the dens, between the superior crus of the cruciate lig. and the apicodental lig/lig of the dens

22

What are the attachment sites of the transverse occipital lig?

to the occipital condyles, above and behind the alar attachment site

23

What is the function of the transverse occipital lig.?

it may assist the alar ligs in limiting or stabilizing axial rotation and perhaps lateral bending and flexion of the craniovertebral junction

24

Where is the lateral atlanto-occipital lig. observed?

just beyond the lateral margin of the rectus capitis lateralis muscle

25

What are the attachment sites of the lateral atlanto-occipital lig?

- transverse process of C1 near or on the posterior tubercle
- jugular process of the occipital bone

26

What is the function of the lateral atlanto-occipital lig.?

it may play a role in limiting axial rotation of the atlanto-occipital joint

27

What movements are facilitated at the median atlanto-axial joint?

- flexion-extension
- rotation
- telescoping (superior-inferior gliding)

28

What is the ADI?

- the Atlanto-Dental Interspace
- a radiographic distance between the surfaces of the anterior bursa of the median atlanto-axial joint

29

The ADI is observed between which surfaces?

the fovea dentis of C1 and the facet for the fovea dentis of C1

30

What is the ADI of children compared with that of adults?

- about 4.5 mm in children
- a range of 2-3 mm or about 2.5 mm in adults

31

What forms the lateral atlanto-axial joint?

- the inferior articular process and facet of C1
- the superior articular process and facet of C2

32

What are the characteristics of the capsular lig of the lateral atlanto-axial joint?

it is lax or loose and demonstrates a meniscoidal fold within the joint cavity

33

What are the accessory lig of the lateral atlanto-axial joint?

- accessory atlanto-axial lig
- anterior atlanto-axial lig
- anterior longitudinal lig
- posterior atlanto-axial lig

34

Where is accessory atlanto-axial lig observed?

anterior to the membrana tectoria/tectorial membrane

35

What are the attachment sites for the accessory atlanto-axial lig?

- the base of the odontoid process and vertebral body of axis to the tubercle for the transverse atlantal lig on the lateral mass of C1
- a superior continuation may attach on the occipital bone just behind that of the alar lig

36

What is the function of the accessory atlanto-axial lig?

it may play a role similar to the alar lig in limiting axial rotation of the atlanto-occipital joint

37

What are the attachment sites for the anterior atlanto-axial lig?

- inferior margin of the anterior arch of C1
- front of the vertebral body of C2

38

What lig attaches to the anterior arch and to the vertebral body of axis?

anterior atlanto-axial lig

39

What is said to be present at the median aspect of the anterior atlanto-axial lig?

anterior longitudinal lig

40

What are the attachment sites of the anterior longitudinal lig between C1 and C2?

- anterior tubercle of the anterior arch of C1
- median aspect of the vertebral body and inferior epiphyseal rim of C2

41

What is the function of the anterior atlanto-axial lig?

it resists extension

42

What is the joint classification of the anterior atlanto-axial lig?

fibrous (amphiarthrosis) syndesmosis

43

What are the attachment sites for the posterior atlanto-axial lig?

- inferior margin of the posterior arch of C1
- superior margin of the lamina of C2

44

What lig attaches to the posterior arch of C1 and to the lamina of C2?

posterior atlanto-axial lig

45

What is the homolog of the posterior atlanto-axial lig?

ligamentum flavum

46

What is the function of the posterior atlanto-axial lig?

resists flexion, axial rotation, and lateral bending

47

What is the joint classification of the posterior atlanto-axial lig?

fibrous (amphiarthrosis) syndesmosis

48

What lig forms the posterior boundary of the spinal canal at the C1/C2 vertebral couple?

posterior atlanto-axial lig

49

What lig forms the medial, posterior boundary of the intervertebral foramen at C1/C2?

posterior atlanto-axial lig

50

What movements are facilitated at the atlanto-axial joint?

- flexion-extension
- axial rotation
- perhaps lateral bending

51

What are the degrees of movement facilitated at the atlanto-axial joint?

- about 20 degrees flexion-extension
- 40 degrees one side axial rotation
- 5 degrees of lateral bending

52

What motion is coupled with flexion to permit more than 5 degrees of motion?

axial rotation

53

The occiput-C1-C2 joint complex accounts for what percent of all cervical axial rotation?

about 60%

54

Which side vertebral artery is compromised with axial rotation of 30 degrees?

the contralateral artery to the side of rotation

55

Which side vertebral artery will begin to be compromised with more than 45 degrees of axial rotation?

the ipsilateral artery to the side of rotation

Decks in Spinal Anatomy I - Exam 3 Class (94):