What percentage of compact bone is organic and what % is salt deposits?
30% organic and 70% is salt deposits.
What makes up 90-95% of the organic part of a bone?
5-10% of the organic bone is what and what will it do?
Ground substance and it controls salt deposition.
What makes the salt deposits in bone?
Ca and Ph which together make hydroxyapatite.
What part of the bone is for tensile force?
What part of the bone is for compressional strength?
Hydroxyapatite crystals will or will not precipitate in the ECF with supersaturation of Ca, and Ph?
What % of total body calcium is in the ECF?
What % of calcium is intracellular?
Where is 98% of body calcium stored at?
In the bones.
Besides the bone where else is ca stored at?
Liver and GI tract.
Calcium equilibrium in the blood is important for what?
Proper pH of blood to be maintained.
Osteoclast do what and are how active?
They mobilize bone and are active in less than 1% of bones in adults.
Physical stress on bones controls what?
The rate of deposition.
Fracutres of bones do what?
Maxinally activates osteoblasts.
What is a callus?
When fixing a fracture it is the depostition of ca salts between ends.
What is the normal amount of calcium in the ECF?
High levels of calcium in ECF will do what to the nervous system?
Ph or Phosphorus is found where in the body?
1% in ECF, 15% intracellular and 85% is in bones.
Phosphorus assists in what?
What is the main purpose of PTH and where is it made at?
Made in the parathyroid gland it controls the ECF concentration of Ca, and Ph.
What will an over and under active parathyroid gland lead to?
over- Hypercalcemia and osteoporosis. Under- leads to hypocalcemia and tetany.
Chief cells in the parathyroid gland secrete PTH and are called what when they are inactive?
What is Osteolysis?
The removal of bone salts caused by PTH activating osteoclasts.
With hypoparathyroidism what happens to Serum levels of Phosphorus?
They are increased.
How can hypoparathyroidism cause death?
Can lead to laryngeal tetany and respiratory obstruction.
How is Hypoparathyroidism treated?
supplements. Instead Vitamin D is given up to 100,000 IU/month, and Ca supplements 1-2 g./day.
Tetany occurs when Ca serum levels fall how low?
6mg/dl or falls by 35%.
Death from low levels of serum Ca occurs at what levels of calcium?