VTPP 435 EXAM QUESTIONS AND ANSWERS LATEST UPDATE 100%
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Bone grows in length because
cartilage grows, and then gets replaced by bone, and then more cartilage grows, etc
growing shaft is remodeled by
bone resorbed, bone added by appositional growth, then more bone resorbed
bone is composed largely of
calcified extracellular matrix
compact bone is
dense and used for support
spongy bone or trabecular bone
forms a calcified lattice
osteoblastic and other mesenchymal lineages start out as
mesenchymal stem cells
osteoclastic lineages start out as
pluripotent stem cells
where are osteoblasts located
line the surface of bone and follow osteoclasts in cutting cones
bone differentiation stimulated by
wnts, bone morphogenetic proteins, growth factors, and cytokines, interleuins, insulin-
derived growth factor, and platelet-derived growth factor
osteoblast lineage
mesenchymal stem cells
__________ make type 1 collagen
osteoblasts
________ express parathyroid hormone receptor (PTHR)
osteoblasts
________ produce osteocalcin and bone sialoprotein (extracellular matrix
proteins specific to bone)
osteoblasts
development of the osteocyte
pre-osteoblast -> osteoblast -> osteoid osteocyte -> mineralizing osteocyte -> mature
osteocyte
Osteocyte origin
mesenchymal cells
osteocyte structure
cells with nucleus and thin ring of cytoplasm
primary mediator of mechanical processes
osteocyte
lining cells
inactive osteoblasts on bone
what are present between osteocytes
interconnecting canaliculi
,space occupied by interconnecting canaliculi is called
lacuna
bone formation is regulated by
WNT signaling
osteosclerosis
a disorder that is characterized by abnormal hardening of bone and an elevation in bone
density
WNT are important during ...
development and port-natal life
osteoclast lineage
monocyte/macrophage
monocytes induced to become
osteoclasts
Osteoclast differentiation
-mononuclear cell fusion and multi-nucleation
- driven by receptor activated of nf kappa b ligand (RANKL)
once differentiated, osteoclasts can ...
adhere to bone surface
polarization of osteoclasts facilitate
clear zone, ruffled border formation, and bone resorption
RANKL regulates:
osteoclast formation, function, and survival
importance of calcium
-most abundant positively charged ion
- bones and teeth
- regulates muscle contraction
- excitation and contraction of cardiac muscle
- blood clotting
- allows nerve conduction
- intracellular second messenger
- maintains tight junctions between cells
function of calcium in extracellular matrix
calcified matrix of bone and teeth
function of calcium in extracellular fluid
- neurotransmitter release at synapse
- role in myocardial and smooth muscle contraction
- cofactor in coagulation cascade
- "cement" for tight junctions
- influences excitability of neurons
function of extracellular caclium
- muscle contraction
- signals in second messenger pathways
3 hormones that control calcium balance in the skeleton
PTH, Vitamin D3, Calcitonin
Function of PTH
increases calcium and decreases phosphate
, Function of Vitamin D3
Increases calcium and phosphate
PTH controls what in the kidney
1a-hydroxylase
_______ calcium levels stimulate PTH release which acts at ____, _____, and
_____
decreased calcium levels stimulate PTH release which acts at intestines, kidneys and
bone
PTH activates osteoblastic cells/ osteocytes to release
RANKL
function of calcitonin
inhibits bone resorption and decreases calcium levels
what is calcitonin made by?
clear parafollicular cells in the thyroid gland
calcitonin works by suppressing which bone cells?
osteoclasts
what type of feedback loops control PTH and calcitonin secretion?
negative feedback loops
How does the body know what the serum calcium level is?
The calcium "sensing" receptor
Activating mutations in the calcium sensing receptor lead to...
hypothyroidism
inactivating mutations in calcium sensing receptor lead to ...
hyperthyroidism
Moment
force acting on a bone causing rotation
Moment Arm
Lever that force acts on (some distance away from center of rotation)
basic forces causing fracture
- compression
- tension
- traverse loading
- torsion
bones are weakest in _______ and strongest in _________
weakest- tension, strongest-compression
pure bending -> _________ fracture
transverse
torsion -> _________ fracture
spiral
shear -> _____ fracture
oblique
butterfly due to _____ + ______
bend + shear
Mechanisms of direct (primary) bone healing
- contact healing
- no motion at the fracture site (i.e. rigid internal fixation; absolute stability)
CORRECT A+ GRADED. Buy Quality Materials!
Bone grows in length because
cartilage grows, and then gets replaced by bone, and then more cartilage grows, etc
growing shaft is remodeled by
bone resorbed, bone added by appositional growth, then more bone resorbed
bone is composed largely of
calcified extracellular matrix
compact bone is
dense and used for support
spongy bone or trabecular bone
forms a calcified lattice
osteoblastic and other mesenchymal lineages start out as
mesenchymal stem cells
osteoclastic lineages start out as
pluripotent stem cells
where are osteoblasts located
line the surface of bone and follow osteoclasts in cutting cones
bone differentiation stimulated by
wnts, bone morphogenetic proteins, growth factors, and cytokines, interleuins, insulin-
derived growth factor, and platelet-derived growth factor
osteoblast lineage
mesenchymal stem cells
__________ make type 1 collagen
osteoblasts
________ express parathyroid hormone receptor (PTHR)
osteoblasts
________ produce osteocalcin and bone sialoprotein (extracellular matrix
proteins specific to bone)
osteoblasts
development of the osteocyte
pre-osteoblast -> osteoblast -> osteoid osteocyte -> mineralizing osteocyte -> mature
osteocyte
Osteocyte origin
mesenchymal cells
osteocyte structure
cells with nucleus and thin ring of cytoplasm
primary mediator of mechanical processes
osteocyte
lining cells
inactive osteoblasts on bone
what are present between osteocytes
interconnecting canaliculi
,space occupied by interconnecting canaliculi is called
lacuna
bone formation is regulated by
WNT signaling
osteosclerosis
a disorder that is characterized by abnormal hardening of bone and an elevation in bone
density
WNT are important during ...
development and port-natal life
osteoclast lineage
monocyte/macrophage
monocytes induced to become
osteoclasts
Osteoclast differentiation
-mononuclear cell fusion and multi-nucleation
- driven by receptor activated of nf kappa b ligand (RANKL)
once differentiated, osteoclasts can ...
adhere to bone surface
polarization of osteoclasts facilitate
clear zone, ruffled border formation, and bone resorption
RANKL regulates:
osteoclast formation, function, and survival
importance of calcium
-most abundant positively charged ion
- bones and teeth
- regulates muscle contraction
- excitation and contraction of cardiac muscle
- blood clotting
- allows nerve conduction
- intracellular second messenger
- maintains tight junctions between cells
function of calcium in extracellular matrix
calcified matrix of bone and teeth
function of calcium in extracellular fluid
- neurotransmitter release at synapse
- role in myocardial and smooth muscle contraction
- cofactor in coagulation cascade
- "cement" for tight junctions
- influences excitability of neurons
function of extracellular caclium
- muscle contraction
- signals in second messenger pathways
3 hormones that control calcium balance in the skeleton
PTH, Vitamin D3, Calcitonin
Function of PTH
increases calcium and decreases phosphate
, Function of Vitamin D3
Increases calcium and phosphate
PTH controls what in the kidney
1a-hydroxylase
_______ calcium levels stimulate PTH release which acts at ____, _____, and
_____
decreased calcium levels stimulate PTH release which acts at intestines, kidneys and
bone
PTH activates osteoblastic cells/ osteocytes to release
RANKL
function of calcitonin
inhibits bone resorption and decreases calcium levels
what is calcitonin made by?
clear parafollicular cells in the thyroid gland
calcitonin works by suppressing which bone cells?
osteoclasts
what type of feedback loops control PTH and calcitonin secretion?
negative feedback loops
How does the body know what the serum calcium level is?
The calcium "sensing" receptor
Activating mutations in the calcium sensing receptor lead to...
hypothyroidism
inactivating mutations in calcium sensing receptor lead to ...
hyperthyroidism
Moment
force acting on a bone causing rotation
Moment Arm
Lever that force acts on (some distance away from center of rotation)
basic forces causing fracture
- compression
- tension
- traverse loading
- torsion
bones are weakest in _______ and strongest in _________
weakest- tension, strongest-compression
pure bending -> _________ fracture
transverse
torsion -> _________ fracture
spiral
shear -> _____ fracture
oblique
butterfly due to _____ + ______
bend + shear
Mechanisms of direct (primary) bone healing
- contact healing
- no motion at the fracture site (i.e. rigid internal fixation; absolute stability)
