BACK Flashcards
The Back Consists of
- skin
- subcutaneous tissue
- deep fascia
- muscles
- ligaments
- vertebral column
- ribs
- spinal cord and meninges
- segmental nerves and vessels
levels of vertebrae
cervical (7) thoracic (12) lumbar (5) sacral (5) coccygeal (4) *33 in total
Curvatures of Vertebral Column
- cervical lordosis (secondary)
- thoracic kyphosis (primary)
- lumbar lordosis (secondary)
- sacral kyphosis (primary)
Scoliosis
abnormal curvature and rotation of vertebrae
parts of a typical vertebra
- body
- vertebral arch (pedicles ad laminae)
- vertebral foramen
- spinous process
- transverse processes
- articular processes
cervical vertebrae characteristics
Body: small, wide, concave
Foramen: triangular, large
Transverse processes: small (absent in C7)
Spinous process: bifid
C1
Atlas
no spinous process or body
transverse ligament
C2
dens
thoracic vertebrae characteristics
Body: heart
Foramen: circular, small
Transverse processes: long, articulate with tubercle of rib
Spinous process: long
lumbar vertebrae characteristics
Body: kidney, massive
Foramen: triangular, smaller than C
Transverse processes: long, slender
Spinous process: hatchet-shaped
joints of vertebral bodies (symphyses)
- annulus fibrous: ring consisting of concentric lamellae
- nucleus pulposus: central core of IV disc
* no IV disc between C1 and C2 - anterior longitudinal ligament
- posterior longitudinal ligament
joints of vertebral arches
zygapophysial/facet joints
ligaments of IV joints
- ligamenta flava
- interspinous ligaments
- nuchal ligament
altanto-occipitial joints (a craniovertebral joint)
permit nodding (neck flexion, extension)
atlanto-axisl joints
- L and R lateral atlanto-axial joints
2. median atlanto-axial joint
movements of vertebral column
- lateral flexion/extension (frontal)
- flexion/extension (median saggital)
- rotation of neck and upper trunk
range of movement in vertebral column is limited by
- thickness, elasticity, compressibility of IV discs
- shape and orientation of articular facets
- tension of joint capsules
- resistance of back muscles on ligaments
- attachment to thoracic rib cage
- bulk of surrounding tissues
movement in neck is free because
- IV discs are thick
- articular surfaces of zygapophysial joints are larder and joint planes almost horiztonal
- joint capsules of zygapophysial joints are loose
- neck is relatively slender
spinal cord length
begins at medulla oblongata
ends at conus medullaris
spinal cord enlarged in 2 regions for innervation of limbs
- cervical enlargement: C4-T1
2. lumbosacral enlargement: L1-S3
Cauda equina
spinal nerve roots arising from lumbosacral enlargement and conus medullaris
how many spinal nerves
31 pairs 8 Cervical 12 Thoracic 5 Lumbar 5 Sacral 1 Coccygeal
lumbar cistern
subarachnoid space in the dural sac
spinal meninges
dura mater, arachnoid mater, pia mater surrounding spinal cord
spinal meninges purpose
meninges and CSP surround, support, protect spinal cord and spinal nerve roots
spinal dura mater
outer most covering membrane of spinal cord
spinal arachnoid mater
encloses subarachnoid space
subarachnoid space
- between arachnoid mater and pia mater
- filled with CSF
- contains spinal cords, nerve roots, spinal ganglia
spinal pia mater
innermost covering membrane of spinal cord
superficial extrinsic back muscles
- trapezius
- latissimus dorsi
- levator scapulae
- rhomboids
intermediate extrinsic back muscles
- serratus posterior superior and inferior
- proprioceptive rather than motor in function
intrinsic mack muscles
- maintain posture
- control movements of vertebral column
- enclosed by deep fascia
superficial layer of intrinsic back muscles
- splenius muscles
- lie on lateral and posterior aspects of the neck
- splenion=bandage
- arise from spenius cervicis and splenius capitis
splenius cervicis
cervical vertebrae
splenius capitis
cranium
intermediate layer of intrinsic back muscles
- erector spinae muscles
2. erector spinae
erector spinae divides into
- iliocostalis (lateral column)
- longissimus (intermediate column)
- spinalis (medial column)