Chapter 7 - Physiology of Osseous Tissue

Phosphate

along with calcium this mineral's levels must also be kept in homestasis

osteoclast

Parathyroid hormone increases the ______________ population

raises

PTH raises or lowers? blood calcium by four mechanisms

collagen synthesis

Parathyroid hormone inhibits ______________ ____________ by osteoblasts, thus inhibiting bone deposition

kidneys

Parathyroid hormone promotes reabsorption of calcium by which organ?

calcitriol

Parathyroid hormone promotes the final step of this calcium regulating hormone synthesis in the kidneys

3.5 and 4.0

Phosphate concentration in plasma ranges between ____________ mg/dL

kidneys

calcitriol weakly promotes the reabsorption calcium ions by the ____________ so less is lost in urine

deficiency or excess

____________ or ________ of hormones can cause skeletal abnormalities ranging from stunted growth to extremely tall stature

calculus

a calcified mass in an other wise soft organ is called a __________

hypocalcemia

a calcium deficiency is called? and it can cause excessive excitability of the nervous system and muscle tremors, spasms, or tetany (prolonged contraction; cramps)

hypercalcemia

a calcium excess is called? and it can cause nerve and muscle cells to become less excitable than normal

girls, boys, males

adolescent _____ grow faster than _____ because estrogen has a stronger effect than testosterone; but ______ grow for a longer time

arterial walls

arteriosclerosis is one example of ectopic ossification and consists of calcification of the __________ ________

growth and sex

bone growth is rapid in puberty and adolescence due to surges of _______ hormones and the _____ hormones; these hormones stimulate cell division and activity

osteoclasts

calcitriol increase calcium resportion from the skeleton by stimulating ___________ production; these increase in number and release calcium and phosphate from bones

small intestine

calcitriol increases calcium absorption by which organ

vitamin D

calcitriol is a form of which vitamin?

calcitriol, calcitonin, parathyroid

calcium homeostasis is regulated by which three hormones?

20

how many factors, at least, affect bone; including hormones, growth factors, and vitamins

ectopic

osseous tissue sometimes forms in other organs, resulting in abnormal calcification called ______ ossification; inner thighs of old cowboys, pectoral muscles of football players, addition of another carpal in people who type for a living

calcitonin

is secreted when the blood calcium concentration rises too high; it lowers the concentration by two mechanisms

hydroxyapatite

mineral deposition is a crystallization process in which calcium, phosphate and other ions are taken from the blood plasma and deposited in bone tissue, mainly as needlelike crystals of what?

inhibitors

most tissues have _____________ that prevent the product of calcium and phosphate concentrations reaching the solubility product value, thus not harden their matrix

exchangable

one calcium reserve in the bones is ____________ that is easily released into the tissue fluid; this reserve is essential to muscle and nervous system function

stable pool

one calcium reserve in the bones is the _______ ______ that is incorporated into hydroxyapatite and is not readily exchangable

reducing

one mechanism by which calcitonin lowers calcium concentration is by ________ osteoclast activity

collagen fibers

osteoblasts lay down what type of fiber along the length of the osteon

collagen

osteoclasts also secrete acid phosphatase that digest the _________ of the bone matrix

1100, 99%

the adult body contains about how many grams? of calcium with how many percent in the bones; bone has two calcium reserves

500 to 800, 85 to 90

the average adult has how many grams of phosphorous? of which how many % is in the bones?

9.2 to 10.4

the calcium concentration in the blood plasma is normally how many mg/dL? and must be kept close to this narrow range

seed crystals

the first crystals to form act as what?, that attract more mineral ions, until the matrix is thoroughly calcified

raise

the function of calcitriol is to raise or lower? blood calcium concentration in three ways

mineral resorption

the process of dissolving bone, releasing minerals into the blood

increases

the second mechanism by which calcitonin lowers calcium concentration is by ___________ the number and activity of osteoblasts

hydrochloric acid

the space between the osteoclast and the bone becomes filled with what acid? with a pH of about 4; the acid dissolves the bone minerals

minerals

these collagen fibers become encrusted with __________ that harden the matrix. Hydroxyapatite crystals form only when the product of calcium and phosphate concentrations reaches the solubility product value

osteoclast

this cell can carry out resorption by secreting hydrogen ions into the extracellular fluid outside its ruffled border

calcitriol, parathyroid

this hormone is a calcium regulator and also raises the phosphate level by promoting its absorption from the small intestine?; this calcium regulator _________ lowers the phosphate level by promoting its excretion through urine

calcitriol

this hormone is also necessary for bone deposition; without it, bones become soft, as in rickets in children and osteomalacia in adults

calcitriol

this hormone is produced by the sequential action of the skin, liver, and kidneys

calcitonin

this hormone plays an important role in children where osteoclasts are highly active, but has only a weak effect in adults

calcitonin

this is one of the three hormones that regulate calcium homeostasis; is secreted by C cell, clear cells, of the thyroid gland

Parathyroid hormone/PTH

this is one of the three hormones that regulate calcium homestasis; it is secreted by the parathyroid glands, which adhere to the posterior surface of the thyroid gland

calcium

this mineral must be kept in a state of homeostasis between the bones and the blood

anabolic steroid

use of this lipid by adolescent athletes can cause premature closure of the epiphyseal plates and result in short adult stature.

calcitonin

which hormone lowers blood calcium concentration?

parathyroid

which hormone raises blood calcium concentration and lowers phosphate concentration?

calcitriol

which hormone raises blood phosphate concentration?

parathyroid, calcitriol

which two hormones raise blood calcium concentration?