Back Lecture 2 : ATLANTO-OCCIPITAL & ATLANTO-AXIAL JOINTS

Question 1

Atlanto refers to the…

Answer 1

1st cervical vertebra

Question 2

Where is the Atlantoaxial joint located?

Answer 2

Between the 1st and 2nd cervical vertebrae.

1st and 2nd cervical vertebrae are the atlas and axis, respectively

Question 3

The atlanto - occipital joint is found between the

Answer 3

Atlas and the occipital bone

Question 4

The Atlanto-occipital joint is a,,,

Answer 4

synovial joint of ellipsoid variety

Question 5

The articulating surfaces above and below :

Answer 5

Articulating surfaces
Above: Convex occipital condyles
Below: Concave superior articular facet of atlas

Question 6

The ligaments of the Atlanto-occipital joint :

Answer 6

1. Fibrous capsule
2. Anterior atlanto-occipital membrane
3. Posterior atlanto-occipital membrane

Question 7

Which of the 3 ligaments surrounds the atlanto-occipital joint?

Answer 7

The fibrous capsule

Question 8

Describe the fibrous capsule.

Answer 8

The fibrous capsule is thick postero-laterally and antero-medially

Question 9

The Anterior atlanto‐occipital membrane is the :

Answer 9

Anterior margin of foramen above to upper border of

anterior arch of atlas below

Question 10

What is the anterior atlanto-occipital membrane strengthened by?

Answer 10

Anteriorly strengthened by the anterior longitudinal ligament

Question 11

What is the anterior atlanto-occipital membrane continuous with laterally?

Answer 11

Laterally continuous with the anterior part of capsular

ligament

Question 12

The Posterior atlanto‐occipital membrane is the :

Answer 12

Posterior margin of foramen magnum above to upper

border of posterior arch of atlas below

Question 13

What does the infero-lateral free margin arch over?

Answer 13

Infero-lateral free margin arches over the vertebral artery & C1
nerve

Question 14

What is the posterior atlanto-occipital membrane continuous with laterally?

Answer 14

Laterally continuous with the capsular ligament

Question 15

The blood supply of the atlanto-occipital joint :

Answer 15

Vertebral artery

Question 16

The nerve supply of the atlanto-occipital joint :

Answer 16

C1 nerve

Question 17

The movements of the atlanto-occipital joint :

Answer 17

Ellipsoid joint -biaxial joint)
Flexion / extension (nodding): transverse axis
Lateral flexion: anteroposterior axis

Question 18

How is the nodding “yes” movement made possible?

Answer 18

The nodding “yes” movement is made possible by the articulation of the occipital condyles rocking in superior articular processes of the atlas. This articulation is called the atlantooccipital joint

Question 19

The atlanto-axial joint is comprised of 3 joints, namely :

Answer 19

A pair of lateral atlanto-axial joints and a median atlanto-axial joint

Question 20

The pair of lateral atlanto-axial joints are :

Answer 20

Plane joints
Between inferior facets of the atlas & superior facets of the
axis.

Question 21

The median atlanto-axial joint is a :

Answer 21

Pivot joint
Between the dens & anterior arch & the transverse ligament
of atlas.

Question 22

What does the Lateral atlanto-axial joint have?

Answer 22

It has a :

capsule all around it and a ligamentum flavum

Question 23

What does the lateral atlanto-axial joint form?

Answer 23

The lateral atlanto-axial joint forms the lateral part of the anterior longitudinal ligament

Question 24

What does the medial atlanto-axial joint have anteriorly?

Answer 24

A Loose capsular ligament anteriorly

Question 25

What is the posterior part between the dens and transverse ligament continuous with?

Answer 25

Posterior part between dens & transverse ligament is continuous with the atlanto-occipital joint

Question 26

What is the main support of the medial atlanto-axial joint?

Answer 26

Main support is the transverse ligament which forms part of the cruciform ligament

Question 27

Where does the transverse ligament attach?

Answer 27

The transverse ligament attaches on each side to the medial surface of lateral mass of atlas

Question 28

What happens in the median plane of transverse ligament?

Answer 28

In the median plane fibers extend upward to basiocciput & downward to the body of axis to form Cruciform Ligament of atlas

Question 29

What movements occur at the atlanto-axial joint?

Answer 29

All 3 joints produce rotatory movement around a vertical axis

Question 30

What is the movement limited by?

Answer 30

Movement is limited by alar ligament

Question 31

Muscles producing movement are:

Answer 31

Rectus capitis posterior major Obliquus capitis inferior Splenius capitis of one side Sternocleidomastoid of other side