hormonal regulation of bone tissue *test 2*
_____ hormones protect natural bone growth
thyroid
This disorder is a deficiency of blood calcium that causes an excitability of the nervous system.
hypocalcemia
What disorder?: with less calcium, sodium channels open more easily, so sodium enters cell and excites nervous system.
hypocalcemia
PTH causes a ____ in osteoclast activity.
increase
Parathyroid hormone causes a(n) _____ in blood clacium
increase
Secretion of calcitonin causes _____ osteoblast activity.
increased
PTH leads to _____ of calcium
conservation
At about _____ mg/ dL, hypercalcemia can cause muscle weakening, sluggishness, or cardiac arrest.
12
hypocalcemia can cause laryngoplasm and suffocation at ___ mg/ dL
4
Hypocalcemia can cause muscle spasms at ___ mg/ dL
6
Correction for hypocalcemia: Blood calcium is decreased. ______ is secreted. This leads to a(n) ______ in osteoclast activity, a(n) ______ in osteoblast activity, _____ urinary phosphate excretion, and ____ urinary calcium excretion. The _____ in osteoclast activity leads to ____ bone resorption. The ____ in osteoblast activity leads to ____ bone deposition. _____ urinary phosphate excretion leads to ______ of hydroxyapatite crystals. _____ urinary calcium excretion leads to ______ of calcium. All of this leads to an increase in blood calcium
PTH, increase, decrease, more, less, increase, more, decrease, less, more, prevention, less, conservation
PTH causes osteoblasts to release ______, an osteoclast stimulating factor that leads to an increase in the osteoclast population.
RANKL
sporadic injections of low levels of PTH causes ____ ___
bone deposition
PTH affects many organs involved in calcium regulation including ____, ____, and ____.
bone, kidneys, intestines
this hormone increases the number and activity of osteoblasts
calcitonin
this hormone is important in children, but not really adults because osteoclasts are more active in children. having a deficiency does not lead to a disease in adults
calcitonin
this hormone is secreted by the cells of the thyroid gland
calcitonin
this hormone reduces bone loss in osteoporosis
calcitonin
this hormone reduces osteoclast activity as much as 70%
calcitonin
Correction for hypercalcemia: Blood calcium is increased. Secrete ______. Leads to ______ osteoclast activity and _____ osteoblast activity. This ______ in osteoclast activity leads to _____ bone resorption, which leads to a decrease in blood calcium. This ____ in osteoblast activity leads to ____ bone deposition, which leads to a decrease in blood calcium.
calcitonin, decreased, increased, decrease, less, increase, more
____ increases intestinal absorption and absorption from the skeleton.
calcitrol
____ increases stem cell differentiation into osteoclasts, promotes urinary reabsorption of calcium ions.
calcitrol
______ behaves as a hormone that increases calcium concentration (not PTH).
calcitrol
Calcium phosphate homeostasis depends on _____, _____, and _____ hormone regulation.
calcitrol, calcitonin, parathyroid
______ is created when UV radiation and epidermal keratinocytes convert steroid derivative to cholecaliferol-d3. The liver then converts it to calcidiol. The kidney then converts that to _____.
calcitrol, calcitrol
Bone is a major resource for ______ in the body.
calcium (ca2+)
Changes in _____ can be serious.
calcium (hypocalcemia, hypercalcemia)
______ is needed for neurons, muscle contraction, blood clotting, and exocytosis. There is ~ ____ g in an adult skeleton, and it has a plasma concentration of ~ ___ mg/ dL.
calcium, 1100, 10
Teen anabolic steroid use causes premature _____ of epiphyseal plates
closing
PTH causes a ____ in osteoblast activity.
decrease
Growth stops when ____ _____ closes.
epiphyseal plate
Growth hormone increases thickness of ____ ____
epiphyseal plates
______ prevent loss of osteoblasts, but mostly halt osteoclastic activity. A loss of estrogen causes an up-regulation of osteoclasts, increasing bone turnover.
estrogen
___, ____, ____ ____ all affect bone.
hormones, vitamins, growth factors
disorder that causes blood calcium to bind to cell surface, making sodium channels less likely to open and depressing the nervous system
hypercalcemia
excess of blood calcium
hypercalcemia
____-like growth factors, along with ____, stimulate protein synthesis and growth.
insulin, GH
PTH promotes calcium resorption by ____, calcitrol synthesis by _____, and inhibits ____.
kidneys, kidneys, collagen
PTH causes _____ urinary calcium excretion
less
PTH leads to ____ bone deposition.
less
Reduced osteoclast activity leads to _____ bone resorption.
less
Increased osteoblast activity leads to ____ bone deposition.
more
PTH causes ____ urinary phosphate excretion
more
PTH leads to ____ bone resorption.
more
_____ hormone allows synthesis and bone deposition by osteoblasts.
parathyroid
______ hormone is secreted to combat hypocalcemia
parathyroid
Changes in ____ have little effect.
phosphate
_____ is a component of DNA, RNA, ATP, phospholipids, and pH bufferes. There is ~ ____ g in an adult skeleton, and its plasma concentration is about ~___ mg/ dL. Two plasma forms are _____ and _____.
phosphate, 750, 4, HPO42-, H2PO4-
PTH leads to _____ of hydroxyapatite formation
prevention
Growth is rapid at _____ because hormones stimulate _____ cells, chondrocytes, and matrix in bone plate. Girls- faster and end sooner. Bone- longer and taller.
puberty, osteogenic
Parathyroid hormone _____ blood calcium level
raises
Secretion of calcitonin causes ______ osteoclast activity.
reduced
Calcitrol deficiency- abnormal deficiency is ____ in children and ____ in adults without vitamin d
rickets, osteomalacia