ASU BIO 201 BONE PRACTICE EXAM
QUESTIONS WITH CORRECT DETAILED
ANSWERS
appositional growth - Answer--bones increase in width throughout life, depending on
use
-the deposition of new bone at the surface
-osteoblasts on deep side of periosteum deposit osteoid tissue
-forms circumferential lamellae over the surface
Does bone remodeling happen often? - Answer-- bone remodeling occurs throughout
life, 10% per year
-repairs microfractures (girls wearing heels), releases minerals into blood, reshapes
bones in response to use and disuse
Wolff's law of bone - Answer--architecture of bone determined by mechanical stresses
placed on it and bones adapt to withstand those stresses
-remodeling is a collaborative and precise action of osteoblasts and osteoclasts
-bony processes grow larger in response to mechanical stress
-explains how bones change shape
What else does Wolf's law explain? - Answer--handedness (right or left handed) results
in thicker and stronger bone of the correct bone
-curved bones are thickest where most likely to buckle
-trabeculae form trusses along lines of stress
-large bony projections occur where heavy, active muscles attach (weight lifters have
thickenings at muscle attachment sites)
-bones of fetuses and bedridden people are feautureless bc of lack of stress on bone
interstitial growth in youth - Answer--cartilage grows and bone replaces the cartilage
that is grown
appositional growth in youth - Answer--bone that was previously there is resorbed into
the blood and appositional growth adds bone
-thicken bones that are being used to protect and create less likelihood of fractures
-can change shape, remodel bones, can shorten, thicken, etc.
growth hormone - Answer--most important hormone in stimulating epiphyseal plate
activity in infancy and childhood
-known as GH
-dictates how long we continue to add cartilage under bone
, thyroid hormone - Answer--modulates activity of growth hormone, ensuring proper
proportions (higher metabolism = faster growth)
What promotes adolescent growth spurts? - Answer-- testosterone for males, and
estrogens for females
-however, males can make estrogens and females can make androgens
-excesses or deficits of any hormones can cause abnormal skeletal growth
How does bone growth end? - Answer--bones end growth by inducing epiphyseal plate
closure
Mineral deposition (mineralization) - Answer--crystallization process in which calcium
phosphate and other ions are taken from the blood plasma and deposited in bone tissue
-osteoblasts produce collagen fibers that spiral the length of the osteon
-fibers become encrusted with minerals that harden the matrix
What do osteoblasts neutralize? - Answer-- osteoblasts neutralize normal tissue
inhibitors, present throughout the body and allow salts to precipitate in the bone matrix
-"switches" - turn on and off materials
ectopic ossification - Answer--abnormal calcification
-may occur in lungs, brain, eyes, muscles, tendons or arteries (arteriosclerosis)
calculus - Answer--calcified mass in an otherwise soft organ such as the lung
Lithopedion (stone baby) - Answer--Calcified fetus, usually in Fallopian tubes
calcium homeostasis - Answer--important for health of the body
-calcium needed in neuron communication, muscle contraction, blood clotting, and
exocytosis
-depends on a balance between diet, urinary and fecal losses, and exchanges between
osseous tissue
-regulated by calcitriol, calcitonin, parathyroid hormone
hypoalcemia - Answer--insufficient calcium in the blood
-overreaction of muscles, causes excess excitability (inability to relax)
hypercalcemia - Answer--blood calcium excess
-sodium channels less responsive and nerve and muscles less excitable (sluggish, slow
reflexes)
-rare b/c calcium will precipitate (pee) (kidneys if healthy will get rid of calcium)
carpopedal spasm - Answer-hypocalcemia demonstrated by muscle spasm of hands
and feet
Causes of hypocalcemia - Answer-vitamin D deficiency
QUESTIONS WITH CORRECT DETAILED
ANSWERS
appositional growth - Answer--bones increase in width throughout life, depending on
use
-the deposition of new bone at the surface
-osteoblasts on deep side of periosteum deposit osteoid tissue
-forms circumferential lamellae over the surface
Does bone remodeling happen often? - Answer-- bone remodeling occurs throughout
life, 10% per year
-repairs microfractures (girls wearing heels), releases minerals into blood, reshapes
bones in response to use and disuse
Wolff's law of bone - Answer--architecture of bone determined by mechanical stresses
placed on it and bones adapt to withstand those stresses
-remodeling is a collaborative and precise action of osteoblasts and osteoclasts
-bony processes grow larger in response to mechanical stress
-explains how bones change shape
What else does Wolf's law explain? - Answer--handedness (right or left handed) results
in thicker and stronger bone of the correct bone
-curved bones are thickest where most likely to buckle
-trabeculae form trusses along lines of stress
-large bony projections occur where heavy, active muscles attach (weight lifters have
thickenings at muscle attachment sites)
-bones of fetuses and bedridden people are feautureless bc of lack of stress on bone
interstitial growth in youth - Answer--cartilage grows and bone replaces the cartilage
that is grown
appositional growth in youth - Answer--bone that was previously there is resorbed into
the blood and appositional growth adds bone
-thicken bones that are being used to protect and create less likelihood of fractures
-can change shape, remodel bones, can shorten, thicken, etc.
growth hormone - Answer--most important hormone in stimulating epiphyseal plate
activity in infancy and childhood
-known as GH
-dictates how long we continue to add cartilage under bone
, thyroid hormone - Answer--modulates activity of growth hormone, ensuring proper
proportions (higher metabolism = faster growth)
What promotes adolescent growth spurts? - Answer-- testosterone for males, and
estrogens for females
-however, males can make estrogens and females can make androgens
-excesses or deficits of any hormones can cause abnormal skeletal growth
How does bone growth end? - Answer--bones end growth by inducing epiphyseal plate
closure
Mineral deposition (mineralization) - Answer--crystallization process in which calcium
phosphate and other ions are taken from the blood plasma and deposited in bone tissue
-osteoblasts produce collagen fibers that spiral the length of the osteon
-fibers become encrusted with minerals that harden the matrix
What do osteoblasts neutralize? - Answer-- osteoblasts neutralize normal tissue
inhibitors, present throughout the body and allow salts to precipitate in the bone matrix
-"switches" - turn on and off materials
ectopic ossification - Answer--abnormal calcification
-may occur in lungs, brain, eyes, muscles, tendons or arteries (arteriosclerosis)
calculus - Answer--calcified mass in an otherwise soft organ such as the lung
Lithopedion (stone baby) - Answer--Calcified fetus, usually in Fallopian tubes
calcium homeostasis - Answer--important for health of the body
-calcium needed in neuron communication, muscle contraction, blood clotting, and
exocytosis
-depends on a balance between diet, urinary and fecal losses, and exchanges between
osseous tissue
-regulated by calcitriol, calcitonin, parathyroid hormone
hypoalcemia - Answer--insufficient calcium in the blood
-overreaction of muscles, causes excess excitability (inability to relax)
hypercalcemia - Answer--blood calcium excess
-sodium channels less responsive and nerve and muscles less excitable (sluggish, slow
reflexes)
-rare b/c calcium will precipitate (pee) (kidneys if healthy will get rid of calcium)
carpopedal spasm - Answer-hypocalcemia demonstrated by muscle spasm of hands
and feet
Causes of hypocalcemia - Answer-vitamin D deficiency
