Lecture 13 Flashcards
Three joint complex of C1 and C2
- median: dens articulates with anterior arch (pivot joint)
- 2 lateral Z joints
Primary movement is cervical rotation (50% of all cervical rotation)
Median is a pivot synovial joint
Features of the C3- C7 cervical vertebrae
- small, kidney-shaped body
- bifurcated spinous process (bifurcation increased SA for ligament and muscle attachment)
- transverse foramina for vertebral artery
Features of the thoracic vertebrae
-• Heart-shaped body
• Long spinous process, directed inferiorly
• Long, thick transverse process (for attatchment of ligaments and muscles)
• Costal facets for rib attachment
How do the thoracic vertebrae articulate with ribs
- articualtes with two demifacets
- synovial joints - surrounded by a joint capsule
Features of lumbar vertebrae
• Large kidney-shaped body forVload bearing (transmit force
from upper body)
• Spinous process horizontal
- bigger thicker transverse processes
• Distal end of the spinal cord ends at L1/L2
• Only cauda equina below this level; important site for lumbar puncture
Lumbar puncture
How many fused vertebrae in the sacrum
5
Shape of the sacrum
Inverted triangle, curved
Features of the sacrum
- forms the sacroiliac joint with the hip bones
- sacral canal (superior) + sacral hiatus (inferior) = a continuation of vertebral canal
What forms a continuation of the vertebral canal?
Sacral canal and sacral hiatus
What passes through the anterior and posterior foramina
- lower limb nerves and vessels
- nerve roots
Number of vertebrae in coccyx
Varies - usually 4
What is the vestigial tail in humans?
Coccyx
What articulates with sacrum
Coccygeal Cornu
Two main joints of the vertebral column
- interbody joint
- zygapophysial/facet joint
What kind of joint is the interbody joint
- cartilaginous joint
Location of the interbody joint
- between bodies of adjacent vertebrae
- Includes intervertebral disc
What kind of joint is the zygaphphysial/facet joint
– Synovial, plane joint
Where is the Zygapophysial/facet joint
– Between superior and inferior articular processes of adjacent vertebrae
Two parts of the invertebral disc
– Annulus fibrosus (outer, binds to bone)
– Nucleus pulposus (inner, “pulp”)
Lambar region has a much larger fibrosus region compared to the cervical
Function of the interbody joint
• Separates vertebral bodies
• Binds vertebrae
• Resists compression
• Absorbs shock
• Resists motion in any direction
= Stability and mobility
Features of zygapophysial (Z) joints
• Orientation of facets differ between regions (allows different movement at different levels of the spine)
• Guide and direct movement
• At every level (except C0-C1)
• Cervical – 45 degree angle (faciliatate lateral flexion and rotation)
• Thoracic – coronal plane, almost vertical (roatate or lateral flex) - limited flexion and extention due to the ribs
• Lumbar – sagittal plane (flexion and extention)
What are the implications of Z-joint orientation on the available movement?
• Cervical – 45 degree angle (faciliatate lateral flexion and rotation)
• Thoracic – coronal plane, almost vertical (roatate or lateral flex) - limited flexion and extention due to the ribs
• Lumbar – sagittal plane (flexion and extention)
What is osteoporosis
When bone resorption > bone formation
Osteoplasts are working faster then osteoblasts
Features of osteoporosis
− Reduction in bone mass
−Microstructural changes
−Bones become brittle and loses elasticity
−When bone density drops below a specific level, osteoporosis is diagnosed
What is osteoporosis associated with
ageing and some medical conditions
What does osteoporosis increase risk of
fracture (hip, vertebrae, proximal humerus, wrist)
Osteoporosis of the spine - Vertebral compression fractures
• Prevalence increases with age
• 25% of postmenopausal women, 40% of women > 80 years
• Often occur during trivial events
• Symptoms
– Sudden onset low back pain
– Limited spinal mobility
– Kyphotic deformity
– Height loss
• Diagnosed with x-ray, initial management non-surgical
Two main ligaments of the vertebral column
• Anterior longitudinal ligament
• Posterior longitudinal ligament
Ligamenta flava
Ligamentum nuchae
Supraspinous ligament
Interspinous ligament
Where are the Anterior longitudinal ligament and Posterior longitudinal ligament and what do they attach to
Length of spine, attaching to vertebral bodies and discs
Function of Anterior longitudinal ligament • Posterior longitudinal ligament
- restrict movement between vertebrae in extension and flexion
Where are Ligamenta flava and what do they connect
one on each side, connects laminae
High elastin content
Where is the Ligamentum nuchae and what does it do
from external occipital protuberance to C7, supports head, site of muscle attachment
Where is the supraspinous ligament ?
C7 to sacrum
Attatch to tip of spinous processes
Intersoinous ligament
What function is common to all of these ligaments?
Ligamenta flava
Ligamentum nuchae
Supraspinous ligament
- they all restrict flexion
What is the cause of whiplash injury
- hyperextention of the neck
- e.g from rear-end collision
- anterior longitudinal ligament is stretched or torn
- anterior intervertebral disc (annulus) and vertebrae also affected
Location of the anterior muscles of the vertebral column
- cervical and lumbar
Location of the lateral muscles of the vertebral column
- cervical and lumbar
Location of the posterior muscles of the vertebral column
- cervical, thoracic and lumbar
What controls movemnt and stabilises spine
80% muscles, 20% osseoligamentous)
• Muscles attaching to skull = capitis
• Muscles of spine often named according to the region they are located (cervicis, thoracis, lumborum)
• Multifidus
• Trapezius
• Splenius
• Erector spinae
• Semispinalis
Order them from superficial to deep
• Trapezius • Splenius • Semispinalis • Erector spinae • Multifidus
Posterior muscles
• Trapezius • Splenius • Semispinalis • Erector spinae • Multifidus
What function is common to all these muscles :? • Trapezius • Splenius • Semispinalis • Erector spinae • Multifidus
- they are all located posteriorly
- restrict extention
Where does the trapezius muscle attach
- attaches external occipital protuberance and connects down to clavicle / scapula
- ligament nuchae and spinous processes
How many parts of the trapezius
3
What does the trapezius do
Extends the neck
- both trapezius muscles contracting together causes extention
- lateral flexion - one side
- rotation (oblique fibres)
Selenius capitis and cervicis muscle
- attaches on the midline to the spinous processes
- fans outwards and then attaches to the transverse processes (cervicis) or skull, including mastoid process (capitis)
Fibre orientation of splenius capitis and cervicis muscle
Oblique
Function of splenius capitis and cervicis muscle
- extends
- rotator (diagonal arrangement) - if muscle on left shortens head will rotate to the left
Semispinalis capitis and cervicis
- starts the transverse processed and fibres go inwards to the spinous process (cervicis) or skull (capitis)
Fibre orientation of Semispinalis capitis and cervicis
Oblique
Semispinalis capitis and cervicis function
- rotation - contraction of left muscle turns head to the right
How many parts of the erector spinae?
3
Three parts of erector spine
• Spinalis (medial), underdeveloped
• Longissimus (intermediate)
• Iliocostalis (lateral)
Erector spinae fibre orientations and functions
- straight up and down fibres
- dont allow rotation
- lateral flex - side bend
Multifidus
• Spans the entire length of the spine
• Extends across 2–4 vertebrae
• Largest in lumbar spine
Contributes to extention
Rotation
Erector spinae and multifidus
Real life prosecution
Abdominal muscles
Layered arrangment
1. Rectus abdominis (anterior)
2. External oblique
3. Internal oblique
4. Transverse abdominis
Where do the abdominal muscles attach to
• Ribs and costal cartilages, fascia
• Iliac crest and/or pubic symphysis
Abdominal muscle rotation
Rectus abdominis - orientation: straight up and down: ANTERIOR - FLEXION
External oblique (hands in pocket orientation) - Internal oblique (hands in pocket) - Transverse abdominis: ROTATION
If they all contract together they contribute to spine flexion and if u contract one side it contributes to rotation - external oblique on right will rotate to right and internal oblique on left will rotate right
What do the abdominal muscles maintain
Interabdomal pressure
- cough
- vomit
