bones Flashcards
What is the function of osteoblasts, osteoclasts, and osteocytes?
Osteoblasts make bone, osteoclasts resorb bone, and osteocytes maintain bone.
Where does hematopoiesis occur?
Bone Marrow
What makes up the basic multicellular units of bone? What is its function?
Osteoblasts, osteoclasts, osteocytes, blood vessels, and bone marrow elements. Maintain and remodel the bone
What is the function of osteocytes in the bone?
Coordinate bone resorption and remodeling, they control the osteoblasts making bone and osteoclasts breaking down bone
What is the purpose of RANKL and sclerostin and which cell makes it?
RANKL and sclerostin are signaling molecules that recruit osteoclasts and osteoblasts, osteocytes make them
What components form the matrix or osteoid of the bone?
Type I collagen and proteoglycans and hydroxyapatite crystals
What is the purpose of hydroxyapatite crystals?
Maintain the mineral weight of the bone
How much of the skeleton is replaced annually?
10%
What vitamin determines peak bone mass?
Vitamin D
Draw a diagram of bone and label the bone regions:
growth plate, epiphysis, metaphysis diaphysis, periosteum, and medullary cavity
What type of bone is seen under normal conditions?
Lameliar
Define ossification
The process of bone formation
What disease of presents with decreased bone mass, no serologic changes, and normal mineralization of osteid?
Osteoporosis
What are the risk factors for osteoporosis?
Post menopausal age, pregnancy, immobilization, drugs, thyroid disease, hypogonadism, and cancer
hat are the treatments for osteoporosis?
Resistance exercise, calcium, estrogen, vitamin D, fluoride, and bisphosphonates
What is the difference between traumatic and pathologic causes of fracture?
Traumatic is bone break caused by accident, pathologic is when bone breaks due to an underlying disease like cancer
What are comminuted fractures and related complications?
High energy fracture that causes multiple bone fragments, blood supply to the bone is disrupted = poor healing
What is the function of fibroblasts at the fracture site?
They deposit collagen into the fracture site
What is the name of infection in the bone?
Osteomyelitis
Osteomyelitis of the finger bone due to a hang nail would be the result of what infectious process?
Direct inoculation
What are the characteristic and most common cause of hematogenous osteomyelitis,?
Spread through blood infection, primarily seen in children, bacteria
What is the most common site of hematogenous osteomyelitis in children?
Metaphyseal side of growth plate (location of most blood vessels)
What determines the treatment of bone cancer?
Cell of origin
hat is the most common form of bone cancer in adults?
Metastasis
What are examples of matrix-producing tumors?
Osteosarcoma, chondrosarcoma
What are examples of non-matrix producing tumors?
Ewing sarcoma, metastasis, and multiple myeloma
What is a malignant bone tumor that produces bone matrix? How is treated?
Osteosarcoma, chemotherapy followed by surgery
What is a malignant bone tumor that produce cartilage? How is it treated?
Chondrosarcoma, surgical, does not respond to chemotherapy or radiation
What is the most common primary (not metastasized) bone tumor in adults? What is this disease and how does it present? How is it treated?
Multiple myeloma, abnormal plasma cell production, presents with anemia, bone pain, decreased renal function, and hypercalcemia, treatment is chemo and radiation
T/F: Metastatic bone tumors are more common than primary bone tumors
True
How do metastatic bone tumors usually present?
Pain or fracture
T/F: Surgery of metastatic bone tumor is usually curative
False
What are the most common cancers that metastasize to bone (5)?
Lung, breast,prostate, kidney, and thyroid
What nourishes the articular cartilage?
Synovial fluid
Articular cartilage is vascular/avascular?
Avascular
What remodels the articular cartilage?
Load
What is the purpose of synovial tissue?
Provides nutrients to the joint
Synovial tissue is vascular/avascular and produces a variety of enzymes.
vascular
What three things do diarthrodal joints need to function properly?
Normal load distribution, ligamentous stability, normal synovium.
What is the most common form of arthritis?
Degenerative joint disease
T/F: Synovium is not involved in DJD?
True
What is sub-chondral bone exposure referred to?
Eburnation
What are the causes of DJD?
Abnormal weight bearing, loss of normal water and proteoglycan content in cartilage.
Subchondral cyst and eburnated subchondral bone would be indicative of what disease?
DJD
What happens to the synovial fluid in RA?
Deposition of immune complexes recruits inflammatory cells to the synovial membrane which damages it, it then no longer provides nutrients to the joint
