week 1 back gross anatomy

movable vertebrae

24

fused vertebrae

9

vertebrae function

protect spinal cord, posture, locomotion, and flexible axis for head and torso

primary curvatures

thoracic and sacral (kyphosis)

secondary curvatures

cervical and lumbar (lordosis)

normal kyphosis curvature

20-45 degrees

excessive kyphosis

greater than 50 degrees

normal cervical curvature

20-40 degrees

normal lumbar curvature

40-60 degrees

sway back

combination of lumbar lordosis and thoracic kyphosis

sway back cause

weak abdominal and hip fleoxrs

flat back

decrease in lumbar lordosis; difficulty standing upright

role of vertebrae processes

serve as attachment points for muscles of the back and spine

role of articular surfaces

make up the facet joints of the spine; each region is designed to promote movement

role of vertebral arch

protects spinal cord

role of vertebral body

allows for weight bearing of the spine on each subsequent level

facet joint also known as

zygapophysial joints

facet joints are made up of

inferior and superior articulating processes

C2-C7

permits flexion/extension and reduces rotation

thoracic is mainly for

rotation; side-bending

lumbar is known for

promoting flexion and extension; reducing rotation

C0 on C1

occiput on atlas; facilitates flexion/extension

C1 on C2

atlas on axis; facilitates rotation

C7

most prominent spinous process called vertebra prominens

C7 is most prominent with

neck flexion

characteristics of C1

no vertebral body and no spinous processes

characteristics of C2

dens process; articulates with C1

atlanto-occipital joint

occiput on C1; facilitates flexion and extension of the head on the neck (yes motion)

atlanto-axial joint

C1 on C2; facilitates rotation (no motion)

uncovertebral joints

site of bone spur formation due to friction

rib articulation

superior vertebrae does not have same number; inferior vertebrae and transverse process shares same number

rib 7 articulates with

T6 and T7 vertebral bodies and the transverse process of T7

unique to lumbar spine

accessory process and mamillary process

movements seen in lumbar vertebrae

flexion and extension

L5 vertebrae

wedge-shaped body with a smaller spinous process; transverse process is large and oriented superior and posteriorly

sacral hiatus

the continuation of the vertebral canal to the inferior portion of the sacrum; covered by sacrococcygeal ligament; site of sacral anesthesia

coccyx

focal point for muscle and ligamentous attachments

cervical and lumbar discs are

thicker anteriorly and more susceptible to herniation

thoracic discs are

relatively thin and uniform in shape

annulus fibrosus

outer fibrocartilaginous ring arranged in sheets called lamellae

annulus fibrosus function

resist tensile forces in nearly all directions

nucleus pulposis

gelatinous mass that is a shock absorber and distributes forces

nucleus pulposis component

high water content that decreases throughout day and with aging

anterior longitudinal ligament

resists extension

posterior longitudinal ligament

resists flexion and helps prevent disc protrusion posteriorly

ligamentum flavum

connects laminae to laminae; resists flexion

interspinous ligament

least overall stiffness; resists flexion

supraspinous ligament

terminates around L3-L4; reinforced by the multifidus; resists flexion

intertransverse ligament

outside sagittal plane; not true ligaments; resists lateral flexion

iliolumbar ligament

resists anterior sliding of L5 and S1

cervical spine ligament

tectorial membrane, nuchal ligament, transverse ligament, and alar ligament

tectorial membrane

superior extension of posterior longitudinal ligament in cervical spine

nuchal ligament

superior thickening of supraspinous ligament

transverse ligament

holds C1 against C2

alar ligament

reduces lateral flexion between the occiput and C2

skin and fascia are provided blood supply through

segmental vessels (branches of the intercostal and lumbar vessels)

extrinsic muscles

trapezius, levator scapulae, rhomboid major and minor, latissimus dorsi, and serratus posterior inferior and superior

upper trapezius innervation

cranial nerve XI accessory

muscles involved in respiration

serratus posterior superior and inferior

extrinsic muscle innervation

ventral rami (except trapezius)

intrinsic muscles are protected by

thoracolumbar fascia

intrinsic muscles can be injured due to

poor lifting techniques, posterior hip weakness, prolonged improper positions

intrinsic muscles innervation

dorsal rami

intrinsic muscles when used unilaterally

lateral flexion and rotation

intrinsic muscles when used bilaterally

extension

intrinsic superficial layer

splenius capitus and splenius cervicis

splenius capitus unilateral

side bending and rotation of the head ipsilaterally

splenius cervicis unilateral

side bending and rotation of the neck ipsilaterally

intrinsic intermediate layer

iliocostalis, longissimus, and spinalis

intermediate layer unilateral function

lateral flexion and rotation to ipsilateral side

intrinsic deep layer

semispinalis, multifidus, and rotatores

rotatores facilitates

contralateral rotation

function of the transversospinalis layer (deep layer)

extend and stabilize vertebral column

suboccipital region location

superficial to atlas and axis and deep to semispinalis

suboccipital muscles

rectus posterior major, rectus posterior minor, inferior oblique, superior oblique

rectus posterior minor and major and superior oblique function

extension of the head at atlanto-occipital joint

inferior oblique function

rotation of head to ipsilateral side at atlanto-axial joint

within the suboccipital triangle

vertebral artery and suboccipital nerve

suboccipital nerve

made up of dorsal ramus of C1

vertebral artery

continues superiorly to supply spinal cord and brain

suboccipital triangle borders

rectus capitis major, superior oblique, inferior oblique

outside suboccipital nerve

greater occipital nerve

greater occipital nerve

sensory only, emerges from dorsal ramus of C2

thoracolumbar fascia

network of collagen fibers; superficial and deep layers support muscle attachments that allow the upper body and lower body to work together through the lumbar spine

spondylolysis

fracture without migration of the vertebral body anterior

spondylolisthesis

fracture with migration of the vertebral body anterior; results in spinal stenosis

anterolisthesis

anterior slippage of superior vertebrae

retrolisthesis

posterior slippage of superior vertebrae

spondylolisthesis is most common in

L4-L5 and L5-S1

pars interarticularis fractures can result in

low back pain

lumbar canal stenosis

narrowing of lumbar canal

lumbar canal stenosis symptoms

pain, numbness or weakness in low back, legs, groin, hips

lumbar canal stenosis aggravating factors

walking or standing

lumbar canal stenosis alleviating factors

lying down, sitting, or other flexion-based activities

intervertebral disc diagnosis common at

C5-C6 and L4-L5

intervertebral disc diagnoses symptoms

can press on nerves, causing pain or nerve symptoms down the leg

ntervertebral disc diagnoses intervention

pain medication, physical therapy, chiropractic, surgery

disc degeneration

age related changes

disc prolapse

disc position starts entering spinal canal

disc extrusion

nucleus pulposis starts pushing through the annulus fibrosis