S1B5 - Craniovertebral Joints / Pharynx Flashcards
What joints are responsible for the ‘yes’ movement (nodding yes)? What is the ROM of that movement at those joints?
Atlanto-occipital (AO) joints
- ‘Yes’ movement (~45 degrees each direction)
What bony structures articlate in the atlanto-occipital joints?
Atlanto-occipital (AO) joints
- Synovial joints (condyloid) between occipital condyles and facets on superior surfaces of the lateral masses of the atlas.
At the atlanto-occipital joints, which structures are concave and which are convex?
Atlanto-occipital (AO) joints
- Occipital condyles are convex with complementary concave facets on the atlas
What are the primary movements allowed by the atlanto-occipital joints?
Atlanto-occipital (AO) joints
- Primarily allows flexion and extension.
- Slight rotation and lateral flexion can occur with a bit of ‘dislocation’
How many synovial joints are in the atlanto-axial joints? How many ligamentous articulations?
Atlanto-axial (AA) joints
- Three total synovial joints between the atlas and axis vertebrae plus one ligamentous articulation which create a composite structure allowing for rotation.
What structures form the lateral atlanto-axial joints? How are they oriented?
Atlanto-axial (AA) joints
- Inferior articular facets of the atlas and superior articular facets of the axis form the two lateral atlanto-axial joints (planar). These facets are large and transversely oriented allowing for a large amount of mobility
What structures articulate in the medial atlanto-axial joint? What kind of joint is it? How many joint cavities are there?
Atlanto-axial (AA) joints
- The medial atlanto-axial joint (pivot) is the articulation between the odontoid process (dens) of the axis and the anterior arch of the atlas AND between the odontoid process and transverse ligament of the atlas completing a pivot joint with two joint cavities.
What joint is mainly responsible for the ‘no’ movement of the head? What is the ROM of this motion at this joint?
Atlanto-axial (AA) joints
- ‘No’ movement (shake head ~45 degrees each direction; ~63 degrees = facet dislocation)
What craniovertebral ligament is a continuation of the anterior longitudinal ligament?
Anterior atlanto-occipital membrane
- continuation of the anterior longitudinal ligament
What does the anterior atlanto-occipital membrane connect?
Anterior atlanto-occipital membrane
- continuation of the anterior longitudinal ligament
- connects the anterior arch of atlas and anterior margin of foramen magnum
What cranio-vertebral ligament is in the same relative position as the ligamentum flavum?
Posterior atlanto-occipital membrane
- in same relative position as the ligamentum flavum
What does the posterior atlanto-occipital membrane connect?
Posterior atlanto-occipital membrane
- connects the posterior arch of atlas and posterior margin of foramen magnum
What artery pierces the posterior atlanto-occipital membrane?
Posterior atlanto-occipital membrane
- inferior margin is perforated by the vertebral artery
What craniovertebral ligament is pierced by the vertebral artery?
Posterior atlanto-occipital membrane
- inferior margin is perforated by the vertebral artery
Which CV ligament is a continuation of the posterior longitudinal ligament?
Tectorial membrane
- continuation of posterior longitudinal ligament
What does the tectorial membrane connect?
Tectorial membrane
- connects the body of the axis and anterior margin of foramen magnum to clivus
What other CV ligaments does the tectorial membrane cover?
Tectorial membrane
- covers the deeper cruciate, alar and apical ligaments
What is the strong transverse part of the cruciate (cruciform) ligament attached to?
Cruciate (cruciform) ligament
- has a strong transverse part attached to the lateral masses and anterior arch of atlas posterolateral to the odontoid process (dens)
What joint does the cruciate (cruciform) ligament help form?
Cruciate (cruciform) ligament
- helps form the medial atlanto-axial joint
What is the weak vertical part (longitudinal bands) of the cruciate (cruciform) ligament attached to?
Cruciate (cruciform) ligament
- has a weak vertical part (longitudinal bands) interconnects the body of the axis and the anterior margin of foramen magnum.
What is the alar ligament connected to?
Alar ligament (left and right)
- strong connections between the lateral sides of the odontoid process of C2 and the margin of the foramen magnum of the occipital bone
What is the functional role of the alar ligament?
Alar ligament (left and right)
- minimize rotation
What is the apical ligament connected to?
Apical ligament
- weak interconnection between the tip of dens and the margin of the foramen magnum of the occipital bone
What are the characteristics of a Jefferson’s (Burst) fracture?
Jefferson’s (Burst) fracture
- the arches of the atlas are fractured and the lateral masses are displaced laterally