Lecture 2 Flashcards
Types of Articulation in Vertebral Column
Cartilaginous Articulation:
- Between vertebral bodies and discs
Synovial Articulation:
- Intervertebral: Formed by adjacent vertebral bodies and the intervening intervertebral discs
- Zygapophyseal: Between superior and inferior articular processes of adjacent vertebral bodies.
Intervertebral Symphysis
- Extend between C2-S1
- No intervertebral discs C0-C1 or C1-C2
- Vertebral endplates overlie the discal surfaces of the vertebral bodies
Zygapophyseal Joint:
- Diathrodial (synovial) articulations
- Capsules encloses the facet joints & is highly innervated with nociceptors for proprioception.
- Share 1/3 load-bearing
Zygapophyseal Orientation
Cervical:
- 45 degrees oblique plane
Thoracic:
- Angled 60 degrees
Lumbar:
- Mainly saggital plane orientated 90 degrees
Cervical Uncovertebral Joint
- Small, synovial, but lack synovial membrane
- Lined with fibrocartilage & covered by thin fibrous capsule
- 4 pairs of plane synovial joints C3-C7
- Between unicinated processes of the bodies of lower vertebra.
Uncovertebral Joint Functions
- Guides cervical motion
- Prevents lateral translation
- Reduces Intervertebral discs herniation
- protects vertebral arteries
Ligaments of Vertebral Column
6 main ligaments:
- Anterior longitudinal
- posterior longitudinal
- Ligamentum flavum
- Interspinous
- Supraspinous
- Intertransverse
Anterior Longitudinal Ligament
- Primary spine stabiliser
- Runs along anterior surface of the vertebral bodies from skull to sacrum
- Prevents hyper-extension
- Whiplash injuries
Posterior Longitudinal Ligament
- Along posterior surface of vertebral bodies, inside the vertebral canal from base of skull to sacrum
- Prevents hyper-flexion and posterior disc herniation
- Not as strong as ALL
Interspinous Ligament
- Between adjacent SP
- Thin ligament attaches to another (ligamentum flavum)
- Resists excessive flexion
Supraspinous Ligament
- Attaches tip of SP to the other C7-Sacrum
- Additional support against hyper-flexion
Ligamentum Flavum (Yellow Ligament)
- Connects laminae of adjacent vertebrae
- Base of skull to pelvis
- The strongest
- Protects spinal cord and nerves
- Maintaining spinal posture & assists in returning the spine to neutral position after flexion
Intertransverse Ligament
- Between adjacent TP
- Resists lateral bending
Spine Movements
- Greatest freedom of movement occurs in cervical & lumbar
- Flexion greater in cervical, extension greater in lumbar
Movement of the Spine are a Function of:
- Size and compressibility of intervertebral discs
- Tightness of the joint capsule
- Orientation of the articular facets
- Muscle & ligament function
- Articulations with thoracic cage
Cervical spine divisions
Upper:
- Craniovertebral region
- C1 & C2
Lower cervical spine
Atypical Vertebrae of Cervical
C1, C2 & C7
Typical Cervical Vertebrae
- Body is small. longer horizontally than antero-posteriorly
- Sp short and bifid
- Tp has oval transverse foramen
- vertebral foramen is large & triangular
C1 (Atlas)
- Ring shapes
- Function to cradle occiput & transmit forces to lower C spine
- NO vertebral body
- NO spinous process
C1 (Atlas) Anterior Arch
Contains tubercle & a facet for articulation with dens
C1 (Atlas) Posterior Arch
Contains posterior tubercle, serving as a substitute for SP
C1 (Atlas) Lateral Masses
Thickest parts, supporting the superior & inferior articular facets.
Superior Articular Facets:
- Articulate with occipital bonecondyles for nodding “yes” movements
Inferior Articular Facets:
- Articulate with C2 to form atlantoaxial joint for head rotation
C2 (Axis) Vertebra
Dens:
- Anterior portion that extends superiorly
-
C7
- Longest SP & not bifid
- TP is large, while its foramen is small
- Does not transmit vertebral artery
Typical Cervical Vertebra: Body
- The medial-lateral diameter is greater than anteroposterior diameter
- Size increases slightly from C2-C7
Typical Cervical Vertebra: Uncinate process
- Posterolateral margins of the superior surfaces of the body of C3-C7
- Give upper vertebra the concave shape
Typical Cervical Vertebra: Transverse process
- Unique features of transverse foramen house vertebral artery, vein & venous plexus.
- Groove for spinal nerves
Typical Cervical Vertebra: Spinous Process
- Short, slender & bifid
- Length decreases slightly C2 & C3, constant C3-C5
Typical Cervical Vertebra: vertebral foramen
- Large, triangular to accomadate the enlargement of spinal cord
Intervertebral Discs in Cervical Region
- Thicker anteriorly & taper laterally as discs approach the unicinate process
- Posterior fibres of annulus form thinner-layer less compared to lumbar
- Anterior fibres are thicker in anterior aspect
Cervical Zygapophyseal Joint
- True synovial containing fibroaclipse meniscoids
- 45 degrees to frontal & horizontal plane
Cervical Interbody Joints
- In lower cervical are saddle joints
- Inferior surface is concave
- Superior surface is convex because of uncinate process
Atlanto-Occipital Articulation
- 2 concave superior facets of atlas articulating with the 2 convex occipital condyles of skull
- True synovial
- Flexion-extension
- A pivot articulation between the odontoid process & ring formed by anterior arch & transverse ligament of C1
Atlanto-Odontoid Joint
- Flexion & extension (nodding)
- Allows side to side movement
- Dens functions as a pivot that permits atlas & attached occipital bone to rotate on axis
Atlanto-Axial Joint
- Complex joint C1-C2
- 3 Synovial joints
- Primary movement is rotation
The 3 synovial joints in the Atlanto-Axial Joint
1 Median atlantoaxial joint:
- Between dens & osteoligamentous ring of C1 anterior & transverse ligament posteriorly
2 Lateral atlantoaxial joints:
- Lateral masses of C1-C2
Craniovertebral Ligaments
- Several ligaments
- Attach to axis, atlas or occiput & reinforce articulations of upper 2 vertebrae
1. Anterior atlantoaxial membrane
2. Posterior atlantoaxial membrane
3. Alar ligament
4. Transverse ligament of atlas
5. Cruciate ligament of atlas
6. Tectorial membrane
7. Apical ligament
Anterior & Posterior Atlanto-Occipital Membrane
Anterior:
- A superior continuation of ALL
Posterior:
- Corresponds superiorly with ligamentum flavum
- Laterally it bends with atlantooccipital joint capsules
- Prevents hyperflexion of atlas
Alar Ligament
- Extends from sides of the dens to occipital condyles
- Limits excessive rotation of the head & stabilizes the craniovertebrae junction
- Injury can increase rotational instability
Transverse Atlantal Ligament
- Stretches across the ring of atlas, holding odontoid process in place
- Prevents excessive anterior displacement of atlas
Cruciate Ligament of Atlas
- Connect C1, C2 to the occipital bone of the skull
- Runs from apex of dens to the anterior margin of foramen magnum
- Maintains atlantoaxial stability by securing dens in place
Consists of:
- Transverse ligament of atlas
- Superior & inferior longitudinal bands
Tectorial Membrane
- Broad, strong originates from posterior vertebral body of C2, covers dens & inserts at the anterior rim of foramen magnum
- Continous with PLL
Apical Ligament of Dens
- Connects tip of dens to anterior margin of the foramen magnum
- Provides additional support to odontoid process
- Help stabilise atlantoaxial joint
Axial Muscle
4 groups:
- Muscles in head & neck that do not move the vertebral column
- Muscles that move the vertebral column
- Muscles of rib cage & lateral walls of abdominal & pelvic cavities
- Muscles that form pelvic floor
Erector Spinae
- Majority of muscles of the back & primary extensor of vertebral column
- Controls, flexion, lateral flexion & rotation of vertebral column & maintains lumbar curve
What muscles comprimise the Erector Spinae?
Illiocastalis: (laterally placed)
- Illiocastalis cervicis
- Illiocastalis thoracis
- Illiocastalis lumborum
Longissimus: (intermediatley placed)
- Longissimus capitis
- Longissimus cervicis
- Longissimus thoracis
Spinalis: (medially placed)
- Spinalis capitis
- Spinalis cervicis
- Spinalis thoracic
Transversospinalis Muscles
- From TP to SP of vertebrae
- Multifidus muscles of lumbar help extend and laterally flex
Semispinalis Muscles:
- Semispinalis capitis
- Semispinalis cervicis
- Semispinalis thoracis
Segmental Muscle Group
- Stabilisation of vertebral column
- Bring together SP, TP of each consecutive vertebra.
Include:
- Interspinous
- Intertransversarii
Muscles of Posterior Neck/Head
Superficial Layer:
- Splenius capitis
- Splenius cervicis (colli)
Intermediate Layer:
- Spinalis Colli
- Longissimus Capitis
- Longissimus Cervicis
- Iliocostalis Cervicis
Deep Layer:
- Semispinalis Cervicis (Colli)
Suboccipital Muscles:
- Rectus Capitis Posterior Major & Minor
- Obliques capitis superior & inferior
Spelnius Capitis
Origin: SP & Nuchal ligament of C3-T3
Insertion: Mastoid process, occipital bone of skull
Action:
- Bilateral contraction, extend the neck
- Unilateral contraction rotates & laterally flexes the neck to that side
Splenius Cervicis (Colli)
Origin: SP T3-T6
Insertion: TP of C1-C3
Action:
- Bilateral contraction, extend the neck
- Unilateral contraction rotates & laterally flexes the neck to that side
Illiocostalis Cervicis
Origin: Angles of 3-6 ribs
Insertion: TP of C4-C6
Action:
- Bilateral contraction, extend the neck
- Unilateral contraction rotates & laterally flexes the neck to that side
Longissimus Capitis
Origin: Nuchal Ligament
Insertion: Mastoid Process
Action:
- Bilateral contraction, extend the head
- Unilateral contraction rotates & laterally flexes the head to that side
Longissimus Colli
Origin: TP T1-T6
Insertion: Posterior tubercles of TP C2-C6
Action:
- Bilateral contraction, extend the neck
- Unilateral contraction laterally flexes the neck to that side
Spinalis Cervicis
Origin: Nuchal Ligament
Insertion: SP of C2-C5
Action:
- Bilateral contraction, extend the neck
- Unilateral contraction laterally flexes the neck to that side
Semispinalis Cervicis
Origin: TP of T1-T5 or T6
Insertion: SP of C2-C5
Action:
- Bilateral contraction, extend the neck
- Unilateral contraction laterally flexes the neck to that side
Rectus Capitis Posterior Major
Origin: SP of C2
Insertion: Inferior Nuchal Line of Occipital Bone
Action:
- Bilateral contraction, extend the head
- Unilateral contraction rotates the head to that side
Rectus Capitis Posterior Minor
Origin: Posterior arch C1
Insertion: Inferior nuchal line of Occipital Bone & adjacent area
Action:
- Extends head
Obliquus Capitis Superior
Origin: TP of C1
Insertion: Posterior of occipitial bone
Action:
- Laterally flexes and extends
Obliquus Capitis Inferior
Origin: SP of C2
Insertion: TP of C1
Action:
- Rotates head
Lateral Mucles - Cervical Region
- Scalene Anterior, Middle & Posterior
- Sternocleidomastoid
Scalenes
- Work together to flex, laterally flex & rotate the head
Anterior Muscles - Cervical
- Longus Capitis
- Longus Colli
- Rectus Capitis Anterior
- Rectus Capitis Lateralis
Longus Capitis
Origin: TP C3-C6
Insertion: Basilar portion of occipital bone
Action:
- Together 2 sides flex neck
- Alone each roates head to that side
Longus Colli
Origin: Anterior surfaces of C3-T3
Insertion: Anterior Aspects of C1-C6
Action:
- Flexes or rotates the neck
Rectus Capitis Anterior
Origin: Anterior surface of lateral mass at C1
Insertion: Basilar part of occipital bone, anterior to foramen magnum
Action:
- Flexion of head at the atlanto-occipital joint
Rectus Capitis Lateralis
Origin: Superior surface of Tp at C1
Insertion: Jugular Process of TP at C1
Action:
- Stabilise atlanto-occipital joint
- Assist in lateral flexion of head
