Joints/Veterbral Column/Superficial Back Muscles

• Fibrous
• Cartilaginous
• Synovial

Contains synovial fluid produced by the synovial membrane, which lubricates the joint and has the consistency of egg white

• Surrounds the joint cavity
• "thick, tough, yet pliable membrane

Covers the ends of the bones

• Suture
• Syndesmosis

• Bones of the skull
• Separated by fibrous tissue and are called fontanelles at birth

Complete fusion (synostosis) begins in the early 20's and continues until old age

• Opposed bones joined by intervening fibrous tissue
• I.e. parallel attachment of the radius and ulna

• Synchondrosis
• Symphysis

• Temporary and eventually converted to bone
• I.e epipyseal plate

• Result from elastic and fibrous tissue forming a compressible disk
• Intervertebral disks are a good example

• Plane Joints
• Hinge joints
• Pivot
• Condyloid
• Saddle
• Ball and socket

• These joints produce a gliding movement 
• i.e intercarpal, carpometacarpal joints

• Joints allow movement in one directional plane so these are uniaxial
• I.e. humeroulnar joint or elbow

• Joint allows rotation around a longitudinal axis
• I.e. the joint formed by the 1st and 2nd cervical vertebrae

• These joints allow their components to move in 2 directions at right angles to each other (multiaxial
• I.e. metacarpophalangeal joints

• Joint where the curvature of the articulating surfaces are at right angles
• 1st metacarpal joint (trapeziometacarpal) of the thumb allows for the thumb to be extended (moved laterally from the palm), flexed, and adducted/abducted
• 

• Have the greatest freedom of movement
• Consists of a "ball" fitted snugly into a socket
• i.e. hip joint and glenohumeral joint

• S-shaped structure
• Approx 72-75 cm

• Normally through the bodies of the upper and lower vertebrae with center of gravity being just anterior to sacral promontory
• 

• Thoracic: present at birth and accommodates the thoracic viscera
• Sacral: accommodates the pelvic viscera

• Cervical: forms at about 2-3 months post gestation
• Lumbar: forms at about 8-10 months post gestation

• Cervical: anteriorly convex
• Thoracic: anteriorly concave
• Lumbar: anteriorly convex
• Sacral: anteriorly concave
• 

33 vertebrae total

• 7 cervical vertebrae (flexible)
• 12 thoracic vertebrae (flexible)
• 5 lumbar vertebrae (flexible)
• 5 sacral vertebrae (fused into a sacrum)
• 4 coccygeal vertebrae (fused into a coccyx)

• Smallest size
• Neural arch and transverse foramen
• Flexibility
• Forked spinous process (except for C1 (atlas) and C₇)

• Existence of a long and prominent spinous process (vertebra prominens)
• Occasionally gives passage to vertebral artery, more likely vertebral vein on both sides
• 

Process is thick, nearly horizontal in direction, not bifurcated

Anterior root of transverse process attains a large size and exists as a separate bone

• Heart-shaped bodies 
• Larger than cervical vertebrae
• Long, inferiorly pointed spinous process
• Costal facets- demifacets
• 

• Largest bodies to support more weight
• Thick, short processes
• Vertebral canal which narrows inferiorly
• Mammillary processes and accessory processes
• 

• Triangular shape for stability
• Anterior/posterior sacral foramina
• "buffer" function to absorb forces of gravity
• Sacral hiatus with sacral cornu (horns) on either side, and sacral canal
• 

• Pelvic diaphragm attachment
• Posterior sacrcoccygeal ligament- crosses sacral hiatus
• Lateral sacrococcygeal ligaments, which attach the transverse process of the coccyx to the sacrum
• Usually 4 fused segments, with the upper segment having a cornu (horn and a transverse process)
• 

• Cartilaginous joints
• Synovial joints (gliding)
• Atlanto-axial joint (pivot)
• Atlanto-occipital joint (condyloid)

• Connects C1 (atlas) with C2 (axis)
• Forms a pivot joint which allows the skull to rotate left and left

Connects C1 (atlas) with occipital bone of skull

• Intervertebral discs
• Anterior longitudinal ligament (ALL)
• Posterior longitudinal ligament (PLL)

• Consists of nucleus pulposus (watery gelatinous center) and annulus fibrosus (thick layer of fibrocartilage)
• 

• Runs longitudinally over the anterior surfaces of the vertebral bodies
• Tapers bottom to up and runs outside of the vertebral bodfy

• Runs longitudinally over the posterior surfaces of the vertebral bodies and is contained within the vertebral canal
• Tapers Top to bottom
• Posterior to spinal cord

Why herniations of the nucleus pulposus occur anteriorly in the cervical spine and posteriorly in the lumbar spine

Covers the tips of the spinous processes

• Continuation of the supraspinous ligament into the cervical region
• Provides stabilization of the cervical vertebrae and attachment of cervical muscles

segmental ligaments found between spinous processes

Segmental ligaments found between transverse processes

Elastic ligaments found segmentally between the vertebral laminae

• Posterior tubercle instead of body or spinous process
• Transverse ligament attaches to either side of the posterior surface of the anterior portion of the neural arch-- ligament "snuggles" the odontoid process or dens
• 

• Hunch back
• 

• Accessory Nerve 
• CN XI

Dorsal Scapular nerve

Dorsal scapular nerve

• 2 muscles are small and very thin
• Generally function as accessory muscles of respiration