MSK Flashcards
name a short bone
Carpals and tarsals
what is a sesamoid bone
patella and hyoid
a bone embedded in a tendon with no proper articulations
What type of bone is the scapula
Flat
what is cortical bone
compact dense bone eg the outside of the bone
what is trabecular bone
spongy appearance network of struts with many gaps
high strength
light weight
what is woven bone
fast made disorganized fibers
what type of collagen would you find in bone
Type I and V
what is lamellar bone
organized bone that replaces woven bone, but takes longer to make
what is the diaphysis
the shaft of the bone
what is the epiphysis
the head of the bone
what is the layer of facia that surrounds bones
periosteum
what are the 2 types of ossification processes
endochondral
intramembranous
what is endochondral ossification
Hyaline cartilage occupies space initially but is ossified later on - such as fetal development and long bone fracture healing
what is intramembranous ossification
bone forms directly from mesenchyme
usually for flat and irregular bones what
what forms the primary ossification center in bone formation
osteoblasts
What is a medullary cavity and how is it formed
where bone marrow sits
formed through breaking down of
explain intramembranous ossification process
- Mesenchymal stem cells cluster to form nidus
- Cells in the nidus become osteoprogenitor cells
- Osteoprogenitor cells become osteoblasts
- Osteoblasts produce ECF type 1 collagen
- Some osteoblasts get trapped and become osteoclasts
- Spicules/Spurs grow to become trabeculae, and periosteum forms around it.
What is the epiphysial plate
A growth plate allowing bones to elongate in children as they age
what is the epiphyseal line
where the growth plate has ossified
what mediates mineralization of bone fibrous matrix
vitamin D and Parathyroid hormone
what differentiates into osteoclasts in remodeling
monocytes
what are reasons for remodeling of bone
changing shape replacing woven bone reorientation of fibrils and trabeculae structure response to load calcium release damage repair
What is RANK signaling pathway
RANK Ligand secreted by osteoblasts
binds to monocytes and causes osteoclast differentiation
oestrogen stimulates osteoblast secretion of RANK Ligand
What does OPG stand for
osteoprotegerin
What is the role of OPG
Antagonises RANK L
prevents bone reabsorption
what produces OPG
osteoblasts and stromatolites
what is Wolff’s Law
Bone will adapt to loads under which it is placed
what is Calcitriol
Active Vit D
what does calcitriol do?
promotes absorption of calcium in the duodenum and proximal jejunum
when and where is calcidiol converted to calcitriol
in the kidney in the presence of PTH
Where is calcidiol produced and what is it produced from?
Vit D3 to calcidiol is done in the liver
under cytochrome p450 system
What produces calcitonin and when
Thyroid C-Cells
Hypercalcemia
What regulates serum phosphates
FGF-23
What produces FGF-23 and what does it do?
Produced by osteocytes in response to PTH
decreases calcitriol
increases phosphate excretion in kidneys
- by decreasing Na+ PO4- cotransporters
what is a synarthroses joint
immobile fibrous joints e.g manubriosternal joint
A joint is diathroses. What does this describe
A freely moving synovial joint
Amphiarthroses joint describes what?
slightly mobile joints
intervertebral disks
