Musculoskeletal Flashcards
What type of mutation causes Achondroplasia?
activating mutation
What gene is implicated during Achondroplasia?
FGFR3
What is the mode of inheritance for Achondroplasia?
Autosomal Dominant
How do most mutations resulting in Achondroplasia arise?
sporadically
What does Endochondral bone formation mean?
bone is laid down on pre-existing cartilage
Which type of bones use Endochondral Ossification to grow?
Long bones
What is Intramembranous bone formation?
formation of bone w/o pre-existing collagen
Which type of bones use Intramembranous Ossification?
flat bones
What is the mode of inheritance for Osteogenesis Imperfecta?
autosomal dominant
What type of collagen is affected during Osteogenesis Imperfecta?
Type One
What cause the eyes to be blue during Osteogenesis Imperfecta?
underlying choroidal veins
What are the three common presenting symptoms of Osteogenesis Imperfecta?
Bone fractures
blue sclera
hearing loss
What process is defective during osteopetrosis?
Bone resorption
What cell is defective during Osteopetrosis?
osteoclast
What enzyme is deficient during Osteopetrosis? Leading to loss of what?
Carbonic Anhydrase II
acidic environment for bone resorption
Are bones brittle or strong during Osteopetrosis?
brittle
What are the hematological abnormalities seen during osteopetrosis?
anemia
thrombocytopenia
leukopenia
Why would osteopetrosis result in vision and hearing loss?
impingement of cranial nerves
Why could osteopetrosis present with hydrocephalus?
closure of foramen magnum
What acid/base disorder would osteopetrosis present with? Why?
metabolic acidosis
cant reabsorb bicarb out of renal tubules due to defective carbonic anhydrase
What cells are osteoclasts derived from?
monocytes
What is the definition of Rickets/Osteomalacia?
defective mineralization of osteoid
What cells produce osteoid?
osteoblasts
What are the levels of calcium during osteoporosis?
normal
What are the levels of phosphate during osteoporosis?
normal
What are the levels of ALP during osteoporosis?
normal
What are the levels of PTH during osteoporosis?
normal
What is the MOA of bisphosphonates?
induce apoptosis of osteoclasts
Does the osteoblast or osteoclast have the PTH receptor?
osteoblast
Does Pagets disease effect the entire skeleton?
no
What is the end result of Pagets disease of the bone?
thick sclerotic bone that fractures easily
What is the only abnormal lab during Pagets disease of bone?
increased alkaline phosphatase
What two drugs are used to treat Pagets Disease of Bone?
calcitonin and bisphosphonates
Increasing hat size is indicative of what disease?
PDOB
What are the two complications of Pagets Disease of Bone?
High output heart failure
Osteosarcoma
Where does osteomyelitis usually occur in children?
metaphysis
Where does osteomyelitis usually occur in adults?
epiphysis
What bacteria is the most common cause of osteomyelitis?
S. aureus
What bacteria is the most common cause of osteomyelitis in sexually active young adults?
N. gonorrhoeae
What bacteria is the most common cause of sickle cell disease?
Salmonella
What bacteria is the most common cause of IV drug users?
Pseudomonas
What bacteria is the most common cause of osteomyelitis due to dog bites?
Pasteurella
What disease are Osteomas associated with?
Gardner
What does an osteoid osteoma respond to?
Aspirin
Where does an osteoblastoma arise from?
vertebrae
How does an osteochondroma arise?
lateral projection of growth plate (metaphysis)
What is an osteoblastoma?
malignant proliferation of osteoblasts
What are the three risk factors for an Osteoblastoma?
Rb
Pagets
Radiation
Where does an osteosarcoma most often arise?
metaphysis
What are the two most common locations for an osteosarcoma to arise?
distal femur or proximal tibia
“Lifting of periosteum” is indicative of what bone cancer?
Osteosarcoma
Which bone tumor produces osteoid?
osteosarcoma
‘Soap bubble’ refers to what kind of bone tumor?
Giant cell tumor
Where in a bone does a giant cell tumor most often occur?
epiphysis
What two bones does a giant cell tumor most often occur?
distal femur or proximal tibia
What bone cancer is derived from neuroectoderm?
Ewing
Where in the bone do Ewing Sarcoma arise?
Diaphysis
‘Onion skin’ is indicative of what bone tumor?
Ewing
Small round blue cells are indicative of what type of tumor?
Ewing
What is the translocation of Ewing Sarcoma?
t(11:22)
Where do both chondroma and chondrosarcomas arise?
medulla of bone
In what two locations do chondromas usually arise?
hands and feet
In what two locations do chondrosarcomas usually arise?
pelvis and central skeleton
What is the only cancer that produces osteoblastic metastasis?
Prostate
The fluid lubricating joints is rich in what acid?
Hyaluronic acid
Does osteoarthritis effect DIP joints?
yes
Does rheumatoid effect DIP joints?
no
Which type of arthritis gets worse during the day?
Osteoarthritis
Which nodes are in the DIP joint?
Heberden
Which nodes are in the PIP joint?
Bouchard
Which HLA haplotype is associated with Rheumatoid Arthritis?
DR4
What type of arthritis features Pannus?
Rheumatoid
What is Pannus?
inflammed Granulation tissue
What is ankylosis of a joint?
fusion of joint
What are Rheumatoid Nodules composed of?
central necrosis surrounded by activated histiocytes
Can rheumatoid or osteoarthritis cause vascultiis?
rheumatoid
What is a Baker Cyst?
swelling of bursa behind the knee
In what disease is a Baker Cyst found?
rheumatoid
What is rheumatoid factor?
IgM against the Fc of IgG
What are the two components of synovial fluid during Rheumatoid Arthritis?
neutrophils and high protein
What are the two systemic complications of Rheumatoid Arthritis?
anemia of chronic disease
secondary amyloidosis
What are the four conditions of PAIR?
psoriasis
Ankylosing spondylitis
IBS
Reiter
Does ankylosing spondyloarthritis more often arise in men or women?
men
What happens to the vertebrae during ankylosing spondyloarthritis?
fusion
What are the two extra-articular manifestations of ankylosing spondyloarthritis?
uveitis
aortitis
What bug causes Reactive Arthritis?
chlamydia trachomatis
Infection of which organ system can lead to reactive arthritis?
GI
Which joints does psoriatic arthritis effect?
DIP of hand and foot
Which joint is most often affected during Infectious Arthritis?
Knee
Which two bugs are known to cause infectious arthritis?
Neisseria Gonorrhoeae
S. aureus
What is the mode of inheritance of Lesch-Nyhan?
X-linked recessive
What are two common causes that may precipitate a gout flare?
alcohol or meat
What is the shape of gout needles in joints?
needle
Are gout crystals negative of positively birefringent under polarized light?
negatively
What composes the crystals seen during Pseudogout?
Calcium PyroPhosphate Dihydrate
What is the shape of Calcium PyroPhosphate Dihydrate?
rhomboid
Are CalciumPyroPhosphate Dihydrate Crystals birefringent?
yes
A carcinoma cancer can be associated with what skin and muscle disorder? Especially where?
Dermatomyositis
stomach
In what two locations could a patient develop a rash during Dermatomyositis?
upper eyelid and malar rash
What are the three locations of papules during dermatomyositis?
elbows
knees
knuckles
Which protein marker is present during dermatomyositis?
increased creatine kinase
Which two antibodies are present during dermatomyositis?
ANA and anti-Jo1
What is inflammed during dermatomyositis?
perimysium
What cell invades the perimysium during dermatomyositis?
CD4
What is the difference between polymyositis and dermatomyositis?
polymyositis doesnt involve skin
What is inflammed during polymyositis?
endomysium
Which cell invades the endomysium during Polymyositis?
CD8
What is the function of dystrophin?
Anchoring the muscle fiber to extracellular cytoskeleton
What happens to dystrophin during DMD?
deletion
Is creatine kinase elevated or decreased during DMD?
elevated
What are the two most common causes of death during DMD?
cardiac or respiratory failure
Are antibodies directed at the pre or post synaptic acetylcholine receptor durign Myasthenia Gravis?
post
When does myasthenia gravis get worse?
with use of muscles
When does myasthenia gravis get better?
with rest
What growth can lead to Myasthenia Gravis?
Thymoma
Are Lambert-Eaton antibodies against the pre or post synaptic calcium channel?
pre
Which groups of muscles are weakened during dermatomyositis?
bilateral proximal muscle weakness
What is the firing of the presynaptic calcium channel required for during Lambert-Eaton Syndrome?
acetylcholine release
Which muscle group is most often effected during MG? Manifests as?
eye
diplopia or ptosis
Are the eyes effected during Lambert-Eaton Syndrome?
no
Which muscles are usually effected during Lambert-Eaton Myasthenia Gravis?
proximal
What disease are rhabdomyomas associated with?
Tuberous Sclerosis
What organ is effected by Rhabdomyomas?
heart
Rhabdomyosarcoma stains positive for which protein marker?
Desmin
Why could osteopetrosis result in hydrocephalus?
thickening of foramen magnum
What is the treatment for osteopetrosis?
bone marrow transplant
What is rachitic rosary?
deposition of osteoid at costochondral junction
In what situations is rachitic rosary present?
Rickets
What are the levels of phosphate during osteomalacia?
decreased
What are the levels of calcium during osteomalacia?
decreased
What are the levels of PTH during osteomalacia?
increased
What are the levels of ALP during osteomalacia?
increased
Will osteoblast or osteoclast activity result in increased levels of ALP?
osteoblast
Which class of drugs promote osteoporosis?
glucocorticoids
Is the PTH receptor on the osteoblast or osteoclast?
osteoblast
What type of bone pattern is seen during Pagets Disease?
mosaic
What type of bone is laid down during Pagets?
lamellar
Why could Pagets DIsease of bone result in hearing loss?
impingement of cranial nerves
What are the two complications of Pagets Disease of Bone?
high output cardiac failure
Osteosarcoma
What is osteosarcoma?
malignant proliferation of osteoblasts
What is dactylitis?
vaso-occlusive crisis within the bones of the hands and feet
What class of drugs can cause Aseptic Necrosis of bones?
steroids
Where would Caisson Disease produce aseptic necrosis?
bones
Where does an osteoma most often arise?
surface of facial bones
What population does an osteoid osteoma arise in? Males or females?
young (under 25)
males
Where does an osteoid osteoma often arise?
diaphysis of long bone
What is the difference in size between an osteoid osteoma and an osteoblastoma?
osteoid osteoma = 2cm
Does an osteoblastoma respond to aspirin?
no
Is an osteochondroma continuous with the marrow space?
yes
What can the overlying cartilage of an osteochondroma transform into?
osteosarcoma
In what two populations does an osteosarcoma most often arise?
teenagers and elderly
Radiation exposure increases the liklihood of what bone cancer?
osteosarcoma
What is the risk factor for osteosarcoma in the elderly?
Pagets disease of bone
What is the histological appearance of osteosarcoma?
pleomorphic cells that produce osteoid
Which bone tumor can present with fever?
Ewing’s
What specific structure becomes inflammed during Rheumatoid arthritis?
synovium
What are two things rheumatoid factor is a marker for?
tissue damage and disease activity
What does seronegative spondyloarthritis mean?
seronegative = lacks rheumatoid factor
What two joints can be involved during Ankylosing Spondylitis?
SI joints and vertebrae
What is AMP broken down into?
hypoxanthine
What is GMP broken down into?
guanine
Deposition of uric acid crystals in a joint triggers which immune cells activity?
neutrophils
What color are uric acid crystals under nonpolarized light?
yellow
What atrophies during Dermatomyositis?
perifasicular atrophy
What is the treatment of dermatomyositis?
corticosteroids
What weakens first during DMD, proximal or distal muscles?
proximal
Does Eaton Lambert get better with use?
yes
Lipoblast belongs to what cancer?
Liposarcoma
What is the definition for an osteoid osteoma?
benign tumor of osteoblasts surrounded by rim of reactive bone
What can an osteochondroma sometimes transform into?
chondrosarcoma
What type of bone formation is impaired during Achondroplasia?
endochondral
What bug causes osteomyelitis in diabetics?
Pseudomonas
What is an Osteosarcoma?
malignant proliferation of osteoblasts
Does osteoarthritis affect the PIP?
yes
What type of necrosis during osteomyelitis?
liquefactive
What surrounds the tophi of chronic gout?
fibrosis
