Term
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Definition
Diaphysis - shaft of bone
Epiphysis - ends of bone
Metaphysis - connect shaft to end |
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Term
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Definition
Surrounds outside of bone
Entrance of BVs into bone |
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Term
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Definition
Inner portion, lines medullary cavity
Contains marrow
Site of hematopoiesis |
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Term
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Definition
Spongy/Trabecular/Cancellous Bone - inside
Compact/Cortical Bone - outside |
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Term
| Structures within Haversian System |
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Definition
Also called osteon
Lamellae - rings of matrix
Lacunae - lines separating lamellae, have osteocytes
Haversian canal - contains BVs and nerves |
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Term
| What two structures make up bone? |
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Definition
Matrix - made of collagen
Calcified portion - hydroxyapatite (made of Ca and PO4) |
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Term
| What enzyme can be measured to indicate osteoblast function? |
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Definition
| Alkaline phosphatase - levels increase with osteoblast function |
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Term
| What can very high alkaline phosphatase levels indicate? |
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Definition
| Excessive osteoblast function = bone tumor |
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Term
| What do osteoclasts use to breakdown bone? |
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Definition
H-ATPase - proton pump
Enzymes - acid phosphatase |
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Term
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Definition
| Monocytes (multinucleated) |
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Term
| What do osteoblasts use to trigger RANK receptors on osteoclast precursors? |
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Definition
RANK ligand - activates RANK receptors to stimulate osteoclastic function
OPG - inhibits osteoclast function; increased levels by estrogen |
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Term
| Why is bone breakdown seen in post-menopausal women? |
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Definition
| Due to lower OPG levels because of decreased estrogen |
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Term
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Definition
PTH functions to INCREASE Ca levels in blood
Stimulates osteoclast function via bone resorption |
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Term
|
Definition
Activated in kidney - calcitriol
Stimulates Ca and phosphate absorption in gut
Stimulates both osteoblasts & clasts - but net bone BUILDING (as long as Ca intake is matched) |
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Term
| What happens if Vit D is taken without adequate Ca intake? |
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Definition
| Net bone breakdown (osteoclast function predominates because osteoblasts have no Ca to deposit) |
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Term
|
Definition
Get matrix breakdown
Cortisol is CATABOLIC - breaks down proteins (collagen in matrix) |
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Term
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Definition
Bones need use to stimulate osteoblast function, need gravity as a stimulus
E.g. Astronauts return to earth with significant bone loss |
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Term
| Where does bone growth occur? |
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Definition
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Term
| What do chondrocytes produce? |
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Definition
Cartilage
Calcifies over time at epiphyseal plates and osteoblasts invade and mature into osteocytes |
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Term
| Bone Trauma - Complete vs. Incomplete |
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Definition
Complete - fractured all the way through
Incomplete - not all the way; Greenstick fracture - prominent in soft bones of children |
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Term
| # of fracture lines in bone trauma |
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Definition
Simple = 1 line
Segmented = mutiple lines
Communited = many small fragments/bits |
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Term
|
Definition
ACTIVE force applied to long bone
Occurs top to bottom (longitudinally); forced into another bone (e.g. head of femur into acetabulum) |
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Term
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Definition
DUE to INHERENT weakness in bone, often due to weight bearing over time (passive fracture)
NOTE: Different than impacted, b/c no active force present |
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Term
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Definition
| Incomplete fracture w/ multiple lines (segmented) |
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Term
| Colles' vs. Pott's Fractures |
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Definition
Colles' = distal radioulnar joint; lose tip of radius
Pott's = distal tibiofibuar joint; lose tip of fibula |
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Term
|
Definition
Pain, swelling, loss of function
Crepitus as bone fragments grind together
Early numbness - interruption of nerves in Haversian canal |
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Term
| Where does the hematoma occur after a fracture? |
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Definition
| Under the periosteum - damage to BVs under periosteum |
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Term
| Process of bone healing after a fracture? |
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Definition
Granulation tissue forms around site - fibroblasts, WBCs, chondrocytes, endothelial cells
Forms into a PROCALLUS - cartilage formed by chondrocytes, more secure than scar tissue
Then get BONY CALLUS formation - osteoblasts invade and produce matrix & calcify deposits; forms over large area
Remodelling - balance of osteoblast/clast function; remove some of extra bony callus to repair (takes 3-4 months) |
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Term
| Factors affecting healing of a fracture? |
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Definition
Degree of damage
Approximation of bones (reduce & immobilize)
Foreign material
Systemic factors |
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Term
| Systemic factors affecting healing from fracture? |
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Definition
DM II - insulin resistance leads to decreased protein anabolism, not enough matrix
Glucocorticoids - cause protein breakdown
Nutrition - need adequate protein intake |
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Term
|
Definition
Often seen after fracture; muscles, BVs, nerves around fracture are compartmentalized by fascia
Inflammation = EDEMA at site of damage, increases pressure in compartment to cut off nerves & BVs
Ischemia = slow healing + likely infection |
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Term
| Healing complications of a fracture? |
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Definition
Non-union if bones are not approximated closely enough
Fat emboli from yellow marrow of fracture
Compartment syndrome
Infection - more likely w/ ischemia & compound fracture
Muscle spasms - may mobilize bones = BAD |
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Term
|
Definition
IMMOVABLE joints - FIBROUS tissue
E.g. sutures in skull, gomphoses (teeth sockets) |
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Term
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Definition
| Freely movable joints - SYNOVIAL |
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Term
|
Definition
Slightly movable joints - HYALINE cartilage
E.g. IO joints of forearm/leg, pubis symphsis |
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Term
| What does the synovial membrane do? |
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Definition
| Secretes serous fluid to lubricate joints; fluid contains glycoproteins |
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Term
| Function of bursae at joints? |
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Definition
Act as small pillows surrounding the joints
Function to reduce friction and act as shock absorbers |
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Term
| Tear of tendon vs. tear of ligament |
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Definition
Tendon (muscle to bone) = STRAIN
Ligament (bone to bone) = SPRAIN |
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Term
| Why is healing slow in damaged tendons and ligaments? |
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Definition
| Because there is a poor vascular supply; nutrients can only reach them via diffusion |
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Term
| Difference between subluxation & avulsion |
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Definition
Subluxation = partial dislocation; example = Shopping Mother's Elbow
Avulsion = separation of ligament/tendon from bone (complete strain/sprain) |
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Term
| Example of repetitive strain injury... |
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Definition
Remember strain = tendon, CARPAL TUNNEL
Strain leads to tendonitis; compression of median nerve by swelling & inflammation of transverse carpal ligament (flexor ret) |
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Term
| Causes of KYPHOSIS (hunchback) |
|
Definition
Osteoporosis - compression injuries
Tuberculosis - can cause bone deterioration
Adolescence - vertebral column grows faster than postural muscles |
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Term
| In which populations of people is LORDOSIS commonly seen? |
|
Definition
Pregnant women & obese people
In both cases see an altered center of gravity, so lumbar curvature becomes more posteriorly concave to support |
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Term
|
Definition
Most is idiopathic
Congenital - fused ribs w/ vertebrae
Degenerative - from compression (osteoporosis) |
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Term
|
Definition
Cerebral Palsy - uneven muscular contraction on sides of column
Muscular Dystrophy - also unequal contraction
Trauma - damage to nerves and/or muscles |
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Term
| What type of bone are Haversian systems present in? |
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Definition
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Term
| What lines the medullary cavity of bone? |
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Definition
|
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Term
| Another name for functional scoliosis? |
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Definition
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Term
| What is used as a diagnostic marker for RA? |
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Definition
| Rheumatoid factor (RF) - antibody found in blood |
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Term
|
Definition
Small joints affected first - synovitis (inflammation of synovial membrane in joints)
Pannus build up in joints (granulation material)
Cartilage breakdown and collagen buildup (fibrosis) of joints
Ankylosing of joints (fusion) |
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Term
|
Definition
Small joints affected first (fingers & hand)
Contracture of muscles around joint; unevenly affected can lead to subluxation
Boutonniere deformity in thumb knuckle
Ulnar drift - medially flexed digits
Swan neck deformity - curved phalanges |
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Term
| What type of condition is rheumatoid arthritis considered to be? |
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Definition
| Autoimmune condition (inflammatory) |
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Term
| What signs of inflammation are seen in RA? |
|
Definition
SYSTEMIC
Increased WBC count
Increased ESR (b/c of RBC agglutination)
Presence of C-reactive protein |
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Term
|
Definition
Avoid disuse atrophy by continually moving
Corticosteroids - reduce inflammation
NSAIDs - reduce inflammation |
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Term
| Differences between juvenile RA and adult onset |
|
Definition
In juvenile see LARGE joints affected first
NO detectable RF present, however do see anti-nuclear antibodies (so is still autoimmune)
Still Disease - rash, fever, splenomegaly, uveitis |
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Term
|
Definition
| Increased age, obesity, EtOH abuse |
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Term
| What is the pathophysiology behind gout? |
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Definition
See deposition of uric acid crystals in joints - accumulate in synovial fluids
Commonly see big toe affected
TOPHI develop (nodules) |
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Term
| What can uric acid build-up be caused by? |
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Definition
Excess purine breakdown - chemo, xanthine oxidase overactivity
Poor elimination from body (ESRD) |
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Term
| How many joints does gout usually affect? |
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Definition
| Usually only a single joint |
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Term
|
Definition
Allopurinol - XO inhibitor
Diet - increase fluid intake, increase urine pH; reduce purine intake
Colchicine - inhibit DNA synthesis; inhibits neutrophil growth in joints
Uricosurics - excrete more uric acid in urine |
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Term
| What is Probenecid used to treat? |
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Definition
| Gout - causes additional uric acid excretion in urine |
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Term
| Main joints affected in ankylosing spondylitis? |
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Definition
| Fusion of vertebral joints - 1st in sacroiliac, then intervertebral and costovertebral joints |
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Term
| Genetic marker for ankylosing spondylitis? |
|
Definition
HLA B27 - test for presence in serum
Note: HLA = MHC |
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|
Term
| What occurs to the spine in ankylosing spondylitis? |
|
Definition
See fusion of vertebral joints
Get rigid "poker back"
Develop kyphosis which throws off center of gravity |
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Term
| Treatment of ankylosing spondylitis |
|
Definition
| Anti-inflammatories - NSAIDs, corticosteroids |
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Term
| What type of disease is osteoarthritis? |
|
Definition
BONE (osteo-) and JOINT (-arthritis)
Is DEGENERATIVE (more affected with age) |
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Term
|
Definition
See erosion of articular cartilage at synovial joints - bone on bone friction (exposure of subchondral bone)
Bone spurs form (osteophytes - formed by osteoblasts); narrow joint to reduce mobility
LOCAL INFLAMMATION only (NOT systemic) |
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|
Term
| What type of inflammation is seen in OA? |
|
Definition
Local inflammation, NOT systemic
(NO fever, no CRP, no elevated ESR) |
|
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Term
| Contrast inflammation seen in RA vs. OA |
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Definition
RA = systemic inflammation
OA = acute inflammation |
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Term
|
Definition
Pain in joints, limited mobility w/ bone spur formation
Heberden's nodes (DIPs), Bouchard's nodes (PIPs)
Crepitus due to exposure of subchrondral bone |
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Term
|
Definition
Rest joints to reduce inflammation, BUT be weary of atrophy
NSAIDs & analgesics |
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Term
| Difference between rickets & osteomalacia |
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Definition
Rickets = childhood onset
Osteomalacia = adult onset |
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Term
| Pathophysiology of rickets/osteomalacia? |
|
Definition
Inadequate bone MINERALIZATION - get no hydroxyapatite deposition; however, matrix is still laid down
Therefore get SOFT BONES (matrix w/o calcification) |
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Term
| What can cause rickets/osteomalacia? |
|
Definition
Inadequate Vit D intake (lack of sunlight, malabsorption)
Inadequate Ca & Vit D intake - e.g. Celiac disease
Could be renal pathology - ESRD = inadequate activation of Vit D |
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Term
| Bones seen in osteomalacia VS. osteoporosis? |
|
Definition
Osteomalacia = soft bones (matrix w/o hydroxyapatite)
Osteoporosis = brittle bones (no matrix or hydroxyapatite) |
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Term
|
Definition
Primary - postmenopausal, increased age in men
Secondary - Cushing's (hypercortisolemia), malabsorption of Vit D/Ca/protein |
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Term
| Drugs that are risk factors for osteoporosis |
|
Definition
Caffeine & nicotine
Excess glucocorticoids taken (e.g. for autoimmune condition)
Chemotherapy (interfere with osteoblast mitosis) |
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Term
|
Definition
CANCELLOUS (spongy) bone lost faster than cortical bone
Compression fractures in vertebrae - leading to kyphosis (Dowager's hump) |
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Term
|
Definition
Diet - 1500 mg Ca, 800 IU Vit D per day
Bisphosphonates - prevent osteoclast breakdown with phosphate isomer
Exercise - more stimulation = more osteoblast function
SERMs - activate estrogen receptors in bone to increase OPG levels, inhibit osteoclast function
Calcitonin - increase bone deposition
Strotium Ranelate - St behaves like calcium and increases OPG levels by binding to osteoblasts |
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|
Term
| Strontium Ranelate mechanism & what it is used to treat? |
|
Definition
Used to treat OSTEOPOROSIS
St behaves like Ca, binds to osteoblasts to increase OPG levels and inhibit osteoclast function |
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|
Term
| Difference between muscle spasm vs. cramp |
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Definition
Spasm - involuntary contraction
Cramp - pain resulting from the muscle spasm |
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Term
| What can muscle spasms lead to (vascular problems)? |
|
Definition
Contraction compresses BV's - get local ischemia & pain (causes cramp)
Also, ischemia multiplies breakdown products of lactic acid - additional cramping |
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Term
| What does excess lactic acid buildup cause |
|
Definition
| Muscle spasm causing cramping (pain) |
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|
Term
| What is the ionic basis for TETANY? |
|
Definition
HYPOCALCEMIA - lower extracellular Ca ion concentration leads to a stronger gradient for Na to enter the cell (both neurons and muscles)
Leads to sustained contraction |
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|
Term
| What may tetany be caused by |
|
Definition
Vit D deficiency (low Ca levels in blood)
Alkalosis - decreased H+ levels cause more Ca to be bound to serum proteins; lowers free Ca concentration = hypocalcemia
Hypocalcemia due to low levels of PTH or high levels of calcitonin |
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|
Term
| What is Trousseau's sign? |
|
Definition
Spasm of muscles in hand & forearm
Contraction/flexion of wrist & MCP joints, extension of IP joints |
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|
Term
| What is the defect in muscular dystrophy? |
|
Definition
See a defect in DYSTROPHIN or a dystrophin related protein
Normally dystrophin anchors actin to cell membrane in muscle - defect leads to improper cytoskeletal formation & ion issues |
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Term
|
Definition
X-linked recessive (more seen in males)
Early onset & rapid progression - ascension from hips and legs |
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|
Term
| Myotonic Muscular Dystrophy |
|
Definition
Autosomal dominant disorder (chr 19)
Deals with "dystrophin-linked" complex
Slow progression; 1st in face/hands
Makes it difficult to coordinate contraction b/c of delayed relaxation |
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|
Term
| General characterstics of muscular dystrophy? |
|
Definition
Increased CK levels - released from degenerating muscle; muscle replaced by fat & CT
Cardiomyopathy
Gower's Maneuver - need to climb up themselves to stand up
Vertebral deformities - differential contraction = scoliosis |
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|
Term
| Where is pain and stiffness seen in fibromyalgia? |
|
Definition
| In MUSCLES and TENDONS (NOT in joints) |
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Term
| Possible cause of fibromyalgia? |
|
Definition
| Increased sensitivity to substance P (NT in pain pathways) |
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|
Term
| Treatment of fibromyalgia? |
|
Definition
NSAIDs - inhibit PG synthesis; interfere w/ pain pathways
SSRIs - also alter pain pathways |
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Term
| Where is the site of hematopoiesis? |
|
Definition
| In the endosteum (medullary cavity) |
|
|
Term
| Where are osteocytes located in the osteon? |
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Definition
|
|
Term
| Where are RANK receptors located? |
|
Definition
|
|
Term
| Which two osteoclast processes do the RANK ligand and OPG regulate? |
|
Definition
| Osteoclast activity and osteoclast differentiation |
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|
Term
| How does PTH affect osteoclast function? |
|
Definition
Stimulates RANK ligand production from osteoblasts to act on RANK receptors on osteoclasts
NOTE: There are NO PTH receptors on osteoclasts! |
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|
Term
| Where are PTH receptors located in the bone? |
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Definition
| On OSTEOBLASTS - PTH binding causes RANK ligand production to activate osteoclast function |
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|
Term
| Who are Greenstick fractures more likely to occur in? |
|
Definition
| Children - have softer bones b/c of more cartilage present |
|
|
Term
| What direction does an impacted fracture occur in? |
|
Definition
| Force from TOP to BOTTOM in long bone (occurs longitudinally) |
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|
Term
| Impacted Fracture vs. Compression Fracture |
|
Definition
Impacted - by ACTIVE FORCE pushing down on bone
Compression - by PASSIVE FORCE due to inherent weakness in bone |
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|
Term
|
Definition
| Incomplete fracture w/ multiple fracture lines; often due to continuous weight on leg/ankle |
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|
Term
| Process of healing from a bone fracture (5 steps) |
|
Definition
| Hematoma -> Granulation Tissue -> Procallus -> Bony Callus -> Remodelling |
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|
Term
| 4 factors affecting healing |
|
Definition
Degree of damage
Approximation of bones (want to reduce/immobilize)
Systemic factors - DM II, glucocort., nutrition
Foreign material - weary of infection |
|
|
Term
| Osteoporosis is likely to lead to which kind of scoliosis? |
|
Definition
|
|
Term
| In which pathology is a buildup of PANNUS seen? |
|
Definition
| Rheumatoid arthritis - see build-up of granulation material in joints leading to synovitis |
|
|
Term
|
Definition
Synovitis in joints due to pannus (granulation tissue) build-up
Fibrosis of joints leads to reduced movement
Get ankylosis of affected joints (fusing)
See cartilage erosion at synovial joints (exposed subchondral bone) |
|
|
Term
| Boutonniere deformity, ulnar drift and swan neck deformity are all seen in? |
|
Definition
|
|
Term
| Onset of adult RA vs. juvenile onset? |
|
Definition
Adult - progressive onset, 1st affects small joints
Juvenile - acute onset, 1st affects large joints |
|
|
Term
|
Definition
Allopurinol - XO inhibitor
Colchicine - inhibit DNA synthesis by preventing microtubule formation
Probenecid (Uricosuric) - increase purine excretion |
|
|
Term
| In what condition are bone spurs usually formed? |
|
Definition
|
|
Term
| Inflammation in OA vs. RA |
|
Definition
OA = local inflammation
RA = systemic (ESR, CRP, leukocytosis) |
|
|
Term
| In which pathology are Heberden's and Bouchard's nodes commonly seen |
|
Definition
In osteoARTHRITIS
Heberden's = DIPs, Bouchard's = PIPs |
|
|
Term
| What can celiac disease lead to? |
|
Definition
| Osteomalacia/rickets due to Ca and Vit D absorption abnormalities |
|
|
Term
| In what pathology is Trousseau's sign often seen? |
|
Definition
| Tetany - flexion of wrist & MCP joints, extension of IP joints |
|
|
Term
| Progression of Duchenne's vs. Myotonic MD? |
|
Definition
Duchenne's = rapid progression ascending upwards from hips & legs
Myotonic = slow progression starting in face/hands |
|
|
Term
| What enzyme levels are elevated in muscular dystrophy? |
|
Definition
|
|
Term
| Why are NSAIDs taken in fibromyalgia? |
|
Definition
To inhibit PG synthesis, as PGs are often involved in pain pathways
NOT for inflammation (NO inflammation in fibromyalgia) |
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