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Pathology II - Non-neoplastic bone pathology
Terms in this set (82)
when osteoblasts are surrounded by the matrix they produce?
multipotential stem cells of the bone
Located on surface of bone; initiate bone mineralization
what are the receptors located on osteoblasts that are specific for hormones
What do osteocytes use to communicate with each other
canaliculi and haversian systems
Responsible for bone resoprtion
Where are osteoclasts derived from?
granulocyte monocyte precursor in bone marrow
what is the backbone of bone matrix
type I collagen
The presence of woven bone in the adult patient is always
pathologic: fracture; site of infection, matrix of bone producing tumors
Produced quickly, resists forces equally from all directions, normally seen in the fetal skeleton and at growth plates
what re the 4 types of lamellar bone
Cortex: concentric, circumferential, interstitial
Bone trabeculae: trabecular type (cancellous)
how much of the skeleton is replaced each year
Resorption of bone begins to exceed formation in the
bone resorption is mediated by the; what does this stimulate?
osteoblast, which stimulates osteoclasts via paracrine chemical signaling
what will block RANK-L binding?
what system is important for activating NF-kB, which is essential for the generation and survival of osteoclasts
RANK/RANKL signaling pathway
Where is bone formed from when you have intramembranous formation
what type of formation will cause lengthening of long bones;
failure of closure of the spinal column or cranium
development of long, spider like digits; marfan syndrome
Most common disease of the growth plate; autosomal dominant, but 80% represent new mutation
In achondroplasia where is the mutation occuring
fibroblast growth factor receptor 4 on chromosome 4
what are some of the development abnormalities associated with heterozygous achondroplasia?
shortened proximal extremities
trunk of relatively normal length
bowing of legs
what is the pathogenesis of achondroplasia
disorganized growth plate
premature sealing of growth plate
length of bone is affected but cortices otherwise develop normalling
Characterized by bone fragility, multiple fractures
Manifests in childhood
what is the mutation associated with osteogenesis imperfecta
mutations in genes that code for alpha 1 and alpha 2 chains of the collagen molecule
what are some characteristics of osteogenesis imperfecta that could be a red flag for diagnosis
what is the most common type of osteogenesis imperfecta
osteopenia, or decreased bone mass, that is severe enough to significantly increase risk of fracture
what are the primary causes of oteoporosis?
senile: men and women affected; severity increases with age
what are some of the causes of secondary osteoporosis?
bed rest, paralysis
diet: deficiency in vitamins
Neoplasia: multiple myeloma, carcinomatosis, mast cell disease
Endocrine disorders: hyperparathyroidism, hyperthyroidism
drugs: heparin, steroids, lithium
age related decrease in bone mass is expected because of imbalance of bone formation and resorption beginning in third decade
when is peak bone mass reached?
young adult years
what is associated with accelerated bone loss?
in patients that are postmenopausal and show signs of bone loss what could you prescribe to help reduce the amount of bone loss which would result in fewer fractures?
bone loss due to osteoporosis is most conspicuous in parts of the skeleton containing abundant trabecular bone especially in the
femoral neck and vertebral bodies
what are three morphological changes that you would see due to osteoporosis
trabeculae thin and widely separated
widening of haversian canals
Crushing vertebral bodies
what is also known as marble bone disease?
In osteopetrosis what are you deficient in?
If a patient has osteopetrosis you can start to determine that the patient will most develop....
fractures due to the affected bones being brittle
anemia, thrombocytopenia and neutropenia due to decrease in marrow space available
cranial nerve palsy due to thickened bone compressing nerve roots
what is the gross morphology of osteopetrosis?
bones lack medullary canal
ends of long bones are misshapen
what is the microscopic morphology of osteopetrosis?
bone is not remodeled, often woven
no consistent change in number of osteoclasts
what is the treatment of osteopetrosis?
bone marrow transplant
osteoclasts are derived from
Localized episodes of increased osteoclastic activity and bone resorption
followed by exuberant bone formation
Paget's disease results in
accumulation of excessive amounts of architecturally abnormal, unstable bone
what is phase I of paget's disease
initial phase of osteoclastic activity and bone loss
what is phase II of paget's disease?
mixed osteoclastic and osteoblastic proliferation
what is phase III of paget's disease?
late osteosclerotic phase
dense, mineralized bone with minimal activity
Evidence suggests that paget's disease has an what as its underlying etiology?
what is the most common complaint of paget's disease?
what can paget's disease progress to?
osteosarcoma (osteogenic sarcoma)
what is the histologic view of phase I of paget's disease
bone taeculae lined by large osteoclasts associated with extensive bone resorptioon
what is the histologic view of phase II of paget's disease?
superimposed osteoblastic activity
what is the histologic view of phase III of paget's disease?
osteoblastic activity continues, bone becomes thickened
pathognomonic mosaic pattern of cement lines
what is pathognomonic of paget's disease
mosaic pattern of cement lines
Vitamin D deficiency or disturbance in its metabolism; defective mineralization of bone
Increased unmineralized osteoid
What is the primary cause of hyperparathyroidism?
hyperplasia or adenoma of the parathyroid causing increased PTH
what is the secondary cause of hyperparathyroidism?
prolonged states of hypocalcemia causing compensatory hypersecretion of PTH
Marrow space contains fibrovascular tissue and hemosiderin because of microfractures and hemorrhage
brown tumor (not a true neoplasm)
skeletal changes that occur in chronic renal disease, including those associated with dialysis
what is an incomplete fracture also referred to as?
bone is splintered is called
fracture site communicates with the skin surface
ends of bone at fracture site are not aligned
what are the fracture healing stages?
What phase of fracture healing is being described?
Rupture of blood vessels results in hematoma
fibrin mesh seals off fracture site and serves as framework for fibroblasts and capillary buds
soft tissue callus provides some adhesion for fractured bone, but no support for weight bearing
what phase of fracture healing is being described?
activated periosteal osteoblasts deposit trabeculae of woven bone
Activated mesenchymal cells around the fracture site differentiate into chondroblasts and deposit cartilage around fracture
what phase of fracture healing is being described?
newly formed cartilage undergoes enchondral ossification
bony callus is formed bridging ends of fractured bone
stiffness and strength of bony callus increase to allow weight bearing
what are some causes of osteonecrosis?
thrombosis or embolsim
increased intraosseous pressure
cause chronic pain; collapse of underlying bone causing secondary osteoarthritis
what is the morphology of osteonecrosis?
dead bone surrounded by necrotic adipocytes, necrotic marrow
what is it called when osteoblasts use remaining trabeculae as scaffolding for new bone formation?
what are the most common etiologic agents of osteommyelitis?
pyogenic bacteria and mycobacterium tuberculosis
what is the causative agent of osteomyelitis if the patient also has sickle cell disease
what are the routes of contamination of osteomyelitis?
direct extension from cellulitis/fasciitis
traumatic implantation - surgery or compound fracture
if osteomyelitis tracks under periosteum and spreads into the nearest joint space this is called
what are the classic signs of chronic osteomyelitis
residual necrotic bone of osteomyelitis
reactive bone formed around the infection of osteomyelitis
small intraosseous abscess that frequently involves the cortex and is walled off by reactive bone
mycobacterial osteomyelitis in which infection can destroy discs and vertebrae frequently resulting in permanent compression fractures leading to scoliosis/kyphosis/neurologic deficits
THIS SET IS OFTEN IN FOLDERS WITH...
Pathology II - Infectious disease
Path II - Neoplastic bone pathology
Pathology II - Endocrine disease
Pathology II - Derm 1
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