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