Midterm 3: Buzzword Bingo Flashcards
(479 cards)
Types of bones that use endochondral bone formation
Long bones (humerus, femur, metacarpals, etc); short bones (carpals, tarsals, etc)
Cartilage model of bone forms -> starts to ossify from center outward
Endochondral bone formation
Types of bones that use intramembranous bone formation
Flat bones - clavicle, scapula, bones of the skull, bones of the pelvis
Embryonic mesenchymal cells cluster, differentiate into osteoblasts -> osteoblasts form spicules of bone that coalesce into bone plates
Intramembranous bone formation
Defect in this process leads to underdeveloped or absent clavicles, dental anomalies, larger fontanelles at birth, and osteoporosis
Intramembranous bone formation -> the disorder described is clavicocranial dysplasia
Autosomal dominant mutation in Cbfa1/Runx2
Claviocranial dysplasia - these are transcription factors in genes needed for osteoblast differentiation, so the mutation has the biggest effect on intramembranous bone formation
Impaired cartilage differentiation and growth may impact what kinds of bone development?
Endochondral bone formation, so long and short bones, but not so much flat bones
Zone of the epiphyseal plate that is the most common site of fracture
Hypertrophic zone
AD (heterozygous) mutation leading to constitutive activation of FGFR3 at the proliferative zone of bone
Slows proliferation of bone -> achondroplasia
Part of bone responsible for increasing in length
Epiphyseal plate
Dense bone in diaphysis that transmits force efficiently
Cortical bone
Type of bone found in metaphysis/epiphysis that provides cushioning
Cancellous/trabecular bone
“Butterfly fragment”
The triangular piece of bone that breaks off when a bone is broken under an axial load that is too strong. The side under tension cracks in a direction perpendicular to the axial load, but the side under compression shears, producing the triangular “butterfly fragment”
Cell that controls signaling for bone remodeling, mineralizes bone, and produces type 1 collagen
Osteoblast
Long-lived cell embedded in bone that maintains calcium homeostasis and plays a role in mechanotransduction within the bone
Osteocyte
Cell of hematopoietic origin that looks like a multinucleated giant cell and releases carbonic anhydrase to break down bone
Osteoclast
Bone cells of mesenchymal origin
Osteoblast -> osteocyte
Bone cells of hematopoietic origin
Osteoclast
Functional unit of cortical bone
Osteon/Haversian system
A receptor on osteoclasts that activates signaling pathways to result in bone resorption
RANK
A molecule secreted by osteoblasts that can activate osteoclasts
RANKL
Cellular target of action of activated vitamin D/PTH (what they act on)
Osteoblasts -> induce release of RANKL
Consequence of continuous over-secretion of PTH
“Brown tumors” - a vascular, fibrous lesion that occurs when hyperparathyroidism causes too much bone resorption in order to release more calcium
Net action of pulses of PTH or synthetic analogue (teriparatide)
Building bone