Patho III Ortho Exam Questions
what is the composition of the extracellular matrix of bone? - ANS osteoid (35%)
-type I collagen
-glycosaminoglycans
-other proteins (ex: osteopontin)
minerals (65%)
-primarily hydroxyapatite: provides bone hardness and repository for 99% of Ca and 85% of
phosphorous
what is the function of osteopontin (osteocalcin) protein? what is it produced by? *in red* - ANS
produced by osteoblasts
regulates:
-bone formation
-mineralization
-Ca homeostasis
what is a marker for osteoblast activity? *in red* - ANS osteopontin (osteocalcin)
what are the two types of bone matrix? compare their strengths and when you would see one vs.
the other. - ANS Woven
-fetal development OR fracture repair
-haphazard arranged collagen w/ less structural integrity
Lamellar
-parallel collagen fibers w/ increased strength
-adult mature bone
Osteoblasts
-where are they located?
,-function
-how are they regulated? - ANS located on surface of osteoid matrix
functions: BUILD BONE!
-synthesize, transport, assemble matrix
-regulate mineralization
highly regulated hormonally and through local mediators
what are quiet osteoblasts? - ANS -decreased cytoplasmic volume
-on trabecular surface or embedded within matrix as osteocyte
Osteocytes
-location
-functions - ANS interconnected through intricate network of dendritic cytoplasmic processes via
tunnels in matrix (canaliculi)
functions MATURE BONE CELLS!
-assist with Ca and phos levels
-detect mechanical forces: important for fx repair & movement
-translate forces into biologic action
Osteoclasts
-what are they?
-function --> explain MOA - ANS specialized multi-nucleated macrophages from circulating
monocytes
function: RESORB BONE!
MOA:
,-surface integrin proteins promote attachment of osteoclasts to matrix
-sealed extracellular trench created
-osteoclasts secret acid & neutral proteases dissolving bone components
-Ca and Phos is released when bone is broken down
how is most bone formed during embryogenesis? - ANS endochondral ossification
ABS review: bone parenchyma unit - ANS parenchyma unit: osteon --> complex of concentric
lamellae surrounding a small central canal that contains blood vessels, nerves, loose connective
tissue, and endosteum
ABS review: periosteum vs endosteum - ANS periosteum: outer layer of bone and often remains
intact even if bone is fracture
-This is the reason we cast and splint so that bone fragments don't tear the periosteum
-Has its own nerve supply and blood supply so the bone will heal
endosteum: inner layer that lines the internal bone cavities
-Highly cellular and is composed of mesenchymal progenitor cells that can differentiate into
osteoblasts and fibroblasts
ABS review: muscle physiology
-what is a sarcomere?
-types - ANS sarcomere: functional unit of striated (skeletal) muscle
-chains of sarcomeres = myofibrils
types:
-skeletal: quick voluntary control, limited regeneration
-cardiac: no regeneration
-smooth: slow involuntary control, regenerate well
ABS Review: types of bone - ANS cancellous "spongy" -- usually on ends of bones
, compact "dense" -- usually the shaft
ABS review: anatomic areas of long bones - ANS epiphysis: ends
metaphysis: transition area b/t shaft and end
diaphysis: shaft
physis: growth plate (peds)
ABS review: fracture repair - ANS 1. Hematoma formation: bleeding
2. Fibrocartilaginous callus formation
3. Bony callus formation - bone growth outside initial bone area
4. Bone remodeling
ABS review: types of joints (5) - ANS diarthrosis: free movement (elbow, hip, shoulder, knee)
symphysis: immoveable, fibrocartilaginous
synostosis: bone to bone, no movement (cranial sutures)
synchondrosis: bone to cartilage (growth plates)
syndesmosis: ligamentous connective tissue articulation (tibia, fibula)
ABS review: types of cartilage & locations - ANS hyaline cartilage
location: fetal skeletons, articular & costal cartilages, laryngeal tracheal and bronchial cartilages
what is the composition of the extracellular matrix of bone? - ANS osteoid (35%)
-type I collagen
-glycosaminoglycans
-other proteins (ex: osteopontin)
minerals (65%)
-primarily hydroxyapatite: provides bone hardness and repository for 99% of Ca and 85% of
phosphorous
what is the function of osteopontin (osteocalcin) protein? what is it produced by? *in red* - ANS
produced by osteoblasts
regulates:
-bone formation
-mineralization
-Ca homeostasis
what is a marker for osteoblast activity? *in red* - ANS osteopontin (osteocalcin)
what are the two types of bone matrix? compare their strengths and when you would see one vs.
the other. - ANS Woven
-fetal development OR fracture repair
-haphazard arranged collagen w/ less structural integrity
Lamellar
-parallel collagen fibers w/ increased strength
-adult mature bone
Osteoblasts
-where are they located?
,-function
-how are they regulated? - ANS located on surface of osteoid matrix
functions: BUILD BONE!
-synthesize, transport, assemble matrix
-regulate mineralization
highly regulated hormonally and through local mediators
what are quiet osteoblasts? - ANS -decreased cytoplasmic volume
-on trabecular surface or embedded within matrix as osteocyte
Osteocytes
-location
-functions - ANS interconnected through intricate network of dendritic cytoplasmic processes via
tunnels in matrix (canaliculi)
functions MATURE BONE CELLS!
-assist with Ca and phos levels
-detect mechanical forces: important for fx repair & movement
-translate forces into biologic action
Osteoclasts
-what are they?
-function --> explain MOA - ANS specialized multi-nucleated macrophages from circulating
monocytes
function: RESORB BONE!
MOA:
,-surface integrin proteins promote attachment of osteoclasts to matrix
-sealed extracellular trench created
-osteoclasts secret acid & neutral proteases dissolving bone components
-Ca and Phos is released when bone is broken down
how is most bone formed during embryogenesis? - ANS endochondral ossification
ABS review: bone parenchyma unit - ANS parenchyma unit: osteon --> complex of concentric
lamellae surrounding a small central canal that contains blood vessels, nerves, loose connective
tissue, and endosteum
ABS review: periosteum vs endosteum - ANS periosteum: outer layer of bone and often remains
intact even if bone is fracture
-This is the reason we cast and splint so that bone fragments don't tear the periosteum
-Has its own nerve supply and blood supply so the bone will heal
endosteum: inner layer that lines the internal bone cavities
-Highly cellular and is composed of mesenchymal progenitor cells that can differentiate into
osteoblasts and fibroblasts
ABS review: muscle physiology
-what is a sarcomere?
-types - ANS sarcomere: functional unit of striated (skeletal) muscle
-chains of sarcomeres = myofibrils
types:
-skeletal: quick voluntary control, limited regeneration
-cardiac: no regeneration
-smooth: slow involuntary control, regenerate well
ABS Review: types of bone - ANS cancellous "spongy" -- usually on ends of bones
, compact "dense" -- usually the shaft
ABS review: anatomic areas of long bones - ANS epiphysis: ends
metaphysis: transition area b/t shaft and end
diaphysis: shaft
physis: growth plate (peds)
ABS review: fracture repair - ANS 1. Hematoma formation: bleeding
2. Fibrocartilaginous callus formation
3. Bony callus formation - bone growth outside initial bone area
4. Bone remodeling
ABS review: types of joints (5) - ANS diarthrosis: free movement (elbow, hip, shoulder, knee)
symphysis: immoveable, fibrocartilaginous
synostosis: bone to bone, no movement (cranial sutures)
synchondrosis: bone to cartilage (growth plates)
syndesmosis: ligamentous connective tissue articulation (tibia, fibula)
ABS review: types of cartilage & locations - ANS hyaline cartilage
location: fetal skeletons, articular & costal cartilages, laryngeal tracheal and bronchial cartilages
