16 - MSK Body Wall & Back Flashcards
What are the two compartments of the body wall
dorsal (proterior) extensor
ventral (anterior) flexor
what defines the anterior and posterior compartments
transverse process
- back = dorsal
- front = ventral
what do the left and right dorsal extensors do
cause extension of the spine
What is the flexor compartment innervated by
ventral ramus
what is the extensor compartment innervated by
dorsal ramus
what do mixed spinal nerves consist of
motor and sensory axons
Describe the pathway of the ventral ramus
goes back –> front
gives off muscular branches (deep) –> superficial and give off sensory nerves(sensations to the skin)
Skin defined by dermatome
Describe the pathway of the dorsal ramus
front –> back
deep in muscles –> superficial to skin on posterior body wall
Which regions are capable of flexion and extension
cervical and lumbar regions
What is lateral deviation
using muscles on the same side of front and back
(joints in vertebral column)
What are the three muscles of the anterior body wall
superficial to deep
external obliques –> internal obliques –> transverse abdominus
Create broad tendon sheath
What is the tendon sheath
formed by the muscles of the anterior body wall
rescuts abdominus underneath the tendon sheath (enveloped in tendon sheath)
- have tendinous insertions between muscle group
What do the anterior body wall muscles do
flexing the lumbar vertebrae
increase intrabdominal pressure to aid in: micturition (urination), parturition (uterus growing –> l&b), defecation (sigmoid…)
What are the muscles in the extrinsic muscles of the back
superficial
- trapezius
- rhomboids (deep to trapezius)
- Latissimus dorsi (widest muscle of the back)
origin in the axial skeleton and insertion in the appendicular skeleton
- give aciton on the appendicular skeleton
What are the intrinsic back muscles
deep
attached to vertebral columns, transverse processes and their extensions and the ribs
have action on vertebral column (spine) - rotation, extnesion
innervated segmentally by dorsal ramus (b/c true back muscles)
What are the extrinsic muscles of the back innervated by
ventral raumus (latissimus and rhomboids) –> peripheral nerves that rise off of brachial plexus early on before it gets out to the limb
CN XI (trapezius)
What are the two major systems of intrinsic back muscles
spinotransverse system (big muscles for extension of spine = erector spinae group)
- long muscles
- stay up straight
- stabalize
transversospinal system
- short, dont go very far
- obliquely oriented
- twisting in the vertebrae
How are the intrinsic back muscles innervated
segmentally by the dorsal ramus
at different levels (cervical, thoracic, lumbar
What are the curvatures of the spine
4 major curvatures
- 2 kyphotic (hump) thoracic and sacrum
- 2 lordotic (backwards) cervical and lumbar
What are abnormalities of curvatures of the spine
exaggeration of a normal curve
scoliosis - most common, congenital, muscle paralysis, short leg, lateral deviation
kyphosis - humpback, osteoporosis (poor posture)
lordosis - pregnancy, obesity (natural adaptation)
what are the parts of a typical (thoracic) vertebrae
body (spongey bone, where most of body’s red bone marrow - where most of RBC are made)
pedicles
lamina (root - plate of spinal canal)
transverse processes
spinous process
superior articular process
inferior articular process
What are fibrous joints
What is the function in the vertebrae
joins adjacent bodies of vertebrae and contain interbetertebral discs
least amount of movement but most stable
What structure faciliatates shock absorption in the vertebrae
intervertebral disc
- thick collagen on outside (fibrous ring)
- inside very gelatinous (hydrated - gel cushions)
as you go through the day, water gets squished out of the vertebral column
What are synovial joints
What is the function in the vertebrae
joins adjacent pedicles of vertebrae
some range of mobility (flexion and extension
where do the mixed spinal nerves exit the vertebral column
intervertebral foramina
What is formed once mixed spinal nerves exit the intervertebral foramina
forms a ventral ramus (thicker than dorsal cause more muscles at the front) and dorsal ramus
What are the anterior longitudinal ligaments
help to keep the intervertebral discs in place
very thick
largely composed of collagen fibers (resist tearing and stretching)
What are posterior longitudinal ligaments
help to keep the intervertebral discs in place
very thin
runs entire length of vertebral column
What is the ligamentum flavum
composed of elastin
yellow (flavum = yellow)
- contains elastic tissue
- can stretch and will recoil back to original position
when flex vertebrae, opens spaces in back between the ligament
extension- goes back to original shape
wears out with age –> touch pressure proprioception when impacting spinal cord
exists between the laminu, does not voer the lamin
What are the ligaments in the vertebrae
anterior and posterior longitudinal ligament
ligamentum flavum
interspinous ligament
supraspinous
What is the interspinous ligament
attatchment site for back muscles (transversospinal)
between the spine
What is the supraspinous ligament
most superficial
above/upon the spinous
connects spinous processes of vertebrae
really thick in cervical region
What is the sacroiliac joint
sacrum articulates with the ilium of the pelvic bones = synovial joints
stabalize the joint, represent thickening
some rotation
cocyx wants to stick out the back
What ligaments stabalize the sacroiliac joints
sacrospinous and sacrotuberous ligaments
prevent the rotation of the sacrum
What are the causes of lower back pain
mechanical: ligament sprain or muscle strain
neurogenic: compression of spinal nerves
What is mechanical pain
ligament sprain or muscle strain
well localized
bilateral (usually on the midline, hard to determine which side)
What is neurogenic pain
compression of spinal nerves
pain radiates
often unilateral
What is neurogenic pain caused by
narrowing intervertebral foamina (spinal stenosis)
disc degeneration (usually when older)
- interverebral disc in compressed –> causes intervertebral space to become smaller –> compresses nerves –> generates pain signals and eventually stops
facet joint arthritis
disk herniation: common between vertebrae l4& l5 and vertebrae l5 and l1
- results in entrapment of l5 or s1 spinal nerve respectively
- s1 spinal nerve entrapment is most common
What is the straight leg test
for isolating spinal nerves involved
places traction on the roots of the lumbosacral plexus
ROM 30 = L4
ROM 90 = L5
no pain at 90 = mechanical back pain
ROM 0 = L2-L3`
Which regions have the greates ROM
cervical and lumbar region
Why are the 4 muscles arranged aroudn the joint axis
flexion
extension
lateral deviation (felxion)
circumduction
What does the sternocleidomastoid
flexion of cervical vertebrae
innervated by CN XI
What is the upper fibres of trapezius
extend cervicle vertebrae
innervated by CN XI
What are the muscles that move the lumbar spine
abdominal muscles (flexion)
Spinotransverssystem (no hold back)
intervatted segmentally by dorsal ramaus
transversospinal system (rotain)
