MSK ILS Practical 1

hyaline cartilage location

epiphyseal plates, synovial joints, costal cartilage, nasal cavity, trachea

hyaline cartilage function

• resist compression

• cushion, smooth, low friction for joints

• structural support in pulm system

hyaline cartilage main cell types + cartilage?

• chondroblast + chondrocytes

• T2 collagen

isogenous groups

clusters of chondrocytes from mitosis, in the IM

elastic cartilage location

external ear, eustachian tube, epiglottis

elastic cartilage function

flexible support for soft tissue

elastic cartilage cell types + cartilage?

• chondroblast + chondrocytes

• T2 collagen

fibrous cartilage location

IV disc, pubic symphysis, sternoclavicular joint, TMJ, menisci

fibrous cartilage function

resist deformation under stress

fibrous cartilage major cell type + cartilage?

• fibroblasts (produce T1) + chondrocytes

• T1 + T2 collagen

which types of cartilage have perichondrium?

hyaline + elastic

which types of cartilage have calcification?

• hyaline: endochondral bone formation + aging

• fibrous: bone repair

chondrocytes function?

• mature cells in lacunae

• maintain matrix

chondroblasts function?

• in perichondrium

• produce matrix

interstitial growth of tissue

• growth from within

• via chondrocyte

• articular cartilage + epiphyseal plate

appositional tissue growth

• growth from ends

• via chondroblast in perichondrium

what does intramembranous ossification form and how?

• flat bones (cranial vault, maxilla/mandible, clavicle)

• uses mesenchymal cells —> osteoblasts

what does endochondral ossification form and how?

• skull base, vertebrae, long bones , pelvis

• begins at hyaline —> 1 ossification center (diaphysis) —> 2 ossification center (epiphysis)

zones of ossification

• resting chondrocyte

• proliferating chondrocyte

• hypertrophic chondrocyte

• calcified chondrocyte

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achondroplasia

• overactive FGR3 —> excessive proliferation

• short stature

appositional bone growth

thickening via adding to periosteal

interstitial bone growth

lengthening from epiphyseal plate

periosteum bone layer

• fibrous outer layer

• sharpey fibers (T1)

• from mesenchymal cells

endosteal bone layer

• connective tissue w/o fibers

• from mesenchymal cells —> cytes —> blasts

osteoprogenitor cells

• like fibroblasts

• from mesenchymal cells

• diff into osteoblasts

osteoblasts

• come from osteoprogenitor cells

• provide osteoid (bone matrix)

  • contain T1, proteoglycans, glycoprotein

osteocytes

• from osteoblasts —> mature in bone cell (lacunae)

• formation + maintenance of bone

• heterochromatin, RER, golgi

osteoclasts

• multinucleated phagocytic cells —> mononucleated progenitor

• resorb + remodel

• howship lacunae: resorption bay

what does the Ca2+ and phosphate in bone stored in?

hydroxyapatite crystals

what composes the osteon?

lamellae + haversian canal

what does haversian canals hold?

contain BV, nerves, loose CT

canaliculi

• projections from osteocytes

• comm. via gap junction

• share nutrients

volkmann’s canal

• connect haversian canals

• perpendicular to diaphysis

nutrient arteries

supply spongy bone + marrow

periosteal arteries

supply compact bone

periosteal nerve

carry pain fibers (i.e fracture)

bone repair mechanism

hematoma —> fibrocartilaginous callus —> bone callus —> bone remodel

osteoporosis

• dec bone density

• unbalanced osteoclast > osteoblast

osteomyelitis

• inflammation of bone + marrow via pathogens

• S. aureus MRSA

osteophytes

• bone spurs via mechanical damage or aging

• Heberden or Bouchard nodes

paget’s

• older male, loss of hearing

• inc osteoclast + osteoblast

• bones large but weak

osteomalacia

vit D deficiency —> adult rickets (bow leg, stiffness, weakness)

osteopetrosis

• hereditary

• dec osteoclastic —> inc bone mass

fibrous joint characteristics + types

• fibrous tissues

• coronal suture

• syndesmosis: dentoalveolar + interosseous

primary cartilaginous joint

• synchondroses: hyaline, limited movement

• e.g epiphyseal plate

secondary cartilaginous joint

• fibrocartilage

• slight movement

• symphyses: IV disc

synovial joint characteristics

• joint capsule —> outer fibrous + inner synovial

• reinforced by extrinsic + intrinsic ligaments

synovial: plane joint

• uniaxial gliding

• metacarpals + cuneiforms

• AC joint

synovial: hinge joint

• uniaxial flexion + extension only

• joint capsule

• elbow, interphalangeal, ankle

synovial: saddle joint

• biaxial abduction/adduction + flexion/extension

• sternoclavicular

• carpometacarpal —> thumb joint

synovial: condyloid joint

• biaxial abduction/adduction, flexion/extension, circumduction

• metacarpophalangeal joint —> knuckle

synovial: ball and socket joint

• multiaxial, 3 planes

• round head in concavity

• hip joint

synovial: pivot joint

• uniaxial rotation

• rounded process in bony socket

• atlanto axial joint —> C1 to C2

superficial facia

• directly beneath skin

• contains fat, BV, lymphatics, cutaneous nerves

deep fascia

• covers most of body beneath skin + superficial fascia

• invests fascia that covers muscle + nerve bundle

• compartment formation

compartment syndrome

• inc pressure

• cause: fracture, trauma, exertion

• symptoms: out of proportion pain, worsens in passive stretch, warm/shiny skin

• foot drop

intermuscular septa in arm

• separates anterior flexor + posterior extensor

• forearm also uses interosseous membrane

compartments of thigh

• anterior —> quads, knee extension

• medial —> adductors

• posterior —> hamstrings, hip extension, knee flexion

compartments of leg

• anterior —> dorsiflex foot, extend digits

• lateral —> everts foot

• posterior —> plantarflex foot, flex digits

bursae

fluid-filled sacs lined by synovial membrane

bursitis

• inflammation of bursae —> swelling, dec ROM, septic burst fever

• cause: overuse, trauma, infection, arthritis

synovial/ganglionic cyst

• benign cyst from joint or tendon sheath

• in dorsum of wrist, ankle, foot

• popliteal fossa —> baker’s cyst

synovial cyst

• comm w/ joint

• true synovial lining

ganglionic cyst

• NO comm w/ joint

• NO synovial lining

what is skin ligament?

• fibrous bands extend into subcut tissues

• attach deep dermis to deep fascia

• suspensory ligaments —> breasts

aponeurosis

• flattened tendon sheath created by muscle that anchors muscle to skeleton

• areas that need smoothening

tendinitis

• acute irritation from microtears

• triggered via overactivity, inflammation

tendinosis

• chronic degeneration

• due to overuse, minimal inflammation

sprain

• ligament

• joint stretched beyond limit

• joint stability dec+ inflammation increases by grade

strain

• muscle

• tear of muscle tendon

• disability inc + contraction dec by grade

x ray

• first line

• broken bones, dislocations

• dense —> white

CT scan

• detailed bone anatomy

• complex/occult fracture

MRI

• soft tissue, ligament/tendon

• marrow edema, tumor

• stress fracture

comminuted fracture

• shattered into multiple pieces

• older/brittle bones

what is the atlanto- occipital joint?

• yes nod

• lateral mass + occipital bone

• ALL

jefferson’s fracture

• vertical compression of atlas

• displaces lateral masses

what is the atlanto-axial joint?

• no nod

• Dens + facet for dens

• transverse ligament —> rupture dangerous

• alar ligament keeps dens in place

hangman’s fracture

• pars interarticularis fracture via hyperextension

• displaced anteriorly

cervical vertebrae

• largest vertebral foramen

• bifid process (C3-C6)

• transverse foramina —> arteries + veins (NOT C7)

• uncus process

thoracic vertebrae

• articular facets on transverse process (NOT T11 + T12)

• costal facets/demifacets (NOT T10-T11)

ankylosing spondylitis

• costovertebral

• whiplash

• degeneration (bamboo spine)

• worsens with deep breathing

which vertebra is most prone to fracture?

T12 —> flexion compression (hard landing)

lumbar vertebrae

• triangular vertebral foramen

• L1-L2: spinal cord terminates

spondylolysis

• L4-L5 pars interarticularis fracture

• LBP, central pain, improves with rest

spondylolisthesis

L5 anterior dislocation

spina bifida

L5 and/or S1 neural arches fuse

flexion-distraction (seatbelt)

• L2 + L3 post. lig. complex

• intense flexion —> in kids

• unstable spine, kyphosis

what is orange?

pedicle

what is teal?

superior articular process

what is yellow?

lamina

ligamentum flavum —> elastin

what is the annulus fibrosus?

• surrounds nucleus pulposus

• made of fibrocartilage

• type 1 collagen

what is the nucleus pulposus?

• water + type 2 collagen

• herniation

anterior longitudinal ligament (ALL)

• connects bodies to IV disc

• ONLY ligament that limits extension

posterior longitudinal ligament

• mostly IV disc, more internal

• prevents post. herniation

• pain nerves

zygapophyseal joint

• sup + inf articular processes

• cervical —> lat flex

• L5-S1 —> sit erect

accessory ligament/ligamentum flavum

• from lamina above to below

• prevent flexion

• hypertophied —> push against spinal cord —> stenosis

  • lower limb weakness/pain

what forms the intervertebral foramen?

• sup + inf notches

• pedicle —> roof

• holds root of spinal nerve

• herniated press against L5 or S1 —> sciatica

  • LBP, radiates down back of thigh

what is in the sacral canal?

cauda equina

superficial (extrinsic) 1st layer

trapezius + latissimus dorsi

action of trapezius?

• upper: elevate scapula (shrug)

• middle: retract scapula

• lower: sup. rotate scapula (parallel bars)