Calcium Homeostasis Flashcards
What is the normal range for calcium in plasma?
8.5 - 10mg/dL
What is the average value of calcium in the plasma?
9.4mg/dL or 2.4mmol/L
Which type of bone has greater turnover of Ca2+?
Trabecular bone
What ions primarily make up hydroxyapatite?
Ca2+ and Phosphate
What is the mineral component of bone called?
Hydroxyapatite
Matured bone cells
Osteocytes
Bone forming cells
Osteoblasts
Type of bone responsible for bone resorption
Osteoclast
What cells are osteoclasts derived from?
Monocytes
During bone formation, collagen fibrils form arrays of an organic matrix called
Osteoid
What process facilitates the resorption of bone without a decrease in bone mass?
Osteocytic Osteolysis
Bone formation is inhibited by which hormone?
Cortisol
Why isn’t vitamin D a classic hormone?
It’s is not produced by an endocrine gland
These cells in the skin are the site for vitamin D3 synthesis
Keratinocytes
What is the precursor for cholecalciferol?
7-dehydrocholestrol
What is the precursor for cholecalciferol?
7-dehydrocholestrol
What enzyme found in the liver, takes part in vitamin D synthesis?
25-hydroxylase
What enzyme found in the kidneys, takes part in the synthesis ofvitamin D?
1 alpha hydroxylase
Which enzyme is the point of regulation of vitamin D synthesis?
I alpha hydroxylase
What is the main function of calcitriol?
It stimulates the absorption of Ca2+ from the intestine
What cells in the parathyroid gland is the site for PTH synthesis?
Chief cells
What hormone decreases plasma Ca2+ levels?
Calcitonin
