Calcium Metabolism Flashcards
How is Ca homeostasis maintained
Through ion regulation in GIT, bone and kidney
Where is Ca absorbed
small intestine
Where is Ca excreted
kidney
Where is Ca stored
Bone
What is diffusible ca
Ionised calcium (free calcium) Bound to ions
What is non-diffusable ca
Bound to albumin
bound to globulin
What happens as pH decreases
H+ displaces Ca2+ from binding sites and the amount of iCa2+ increases
What are the 7 questions of physiological functions
Cell differentiation Bones and teeth Glycogen metabolism Protein secretion NT release Muscle contraction nerve excitibility
Causes of rickets and osteomalacia
Lack of dietary vit D and sunlight
malabsorption of fats
Failure to form calcitriol - chronic renal failure
What is calcitonin
Hormone secreted from c cells ( parafollicular cells)
Where is calcitonin secreted from
The thyroid gland
What does calcitonin do
Increase in ca
increase in Calcitonin secretion
inhibits osteoclastic activity so reduces blood calcium
impact of GH on Ca
Promotes +ve ca2+ balance
impact of thyroid hormone on Ca
optimum bone growth
XS - can lead to osteoporosis
impact of GC on Ca
Small amounts of essential for normal bone development
XS- osteoporosis
