Bone profile, Calcium and Phosphate Flashcards
What is the role of the osteoclast
To break down old bone
What is the role of the osteoblast
to build new bone
What is the main substance that makes up bone
Hydroxyapatite
made up of calcium, magnesium, sodium and bicarbonate as well as phosphorous
How is phosphate metabolism maintained
Phosphate homeostasis is a balance between GI uptake, renal excretion/ absorption and movement in and out of bone.
What is the relationship between calcium and phosphate - in health
When Calcium increases, phosphate decreases - and vice versa
What symptoms does hyperphosphatemia present with
non - likely to show signs of hypocalcemia
What are the symptoms of hypophosphatemia
when levels fall below 0.3 muscle weakness may occur, rhabdomyolysis, confusion seizures and rarely coma. Haemolytic anaemia may also present
Which 2 hormones control the concentration of calcium
PTH - parathyroid hormone and calcitonin
What role does vit D play in calcium homeostasis
essential for the utilisation of calciu,
usually, UV light is required in order for the precursors to be made into Vit D. many people are deficient,
The main action is to stimulate the gut to absorb calcium from dietary food
When is calcium normally evaluated
Testing for bone disease, parathyroid issues and kidney impairment.
If a patient has a raised PTH level what will happen to the calcium and phosphate
Calcium will rise and phosphate will fall.
In renal disease what changes will be expected
phosphate levels will be high and calcium levels will be low
What causes a rise in both phosphate and calcium
Boney Mets and bone disease
Which protein transports 40% of all calcium within the blood
Albumin
What relationship will having a raised albumin have on calcium
As calcium is transported within the albumin, the serum calcium will be significantly higher than normal as a proportion
Abnormally low albumin will have what effect on serum calcium
proportionally the serum calcium will be lower due to having less available albumin
What effect does pH have on calcium
having a raised pH will lower the ionised calcium and acidosis will increase the ionised calcium
What is the mechanism of hypercalcemia
When calcium is transported into the ECF from the ICF.
What are the primary causes of hypercalcemia
Cancer and primary hyperparathyroidism
What are the signs and symptoms of hypercalcemia
weakness, depression, lethargy, nausea and vomiting, anorexia and renal stones.
What is the treatment options available for hypercalcemia
fluid resuscitation, diuretics, calcitonin, denosumab, bisphosphonates
What is a paraneoplastic syndrome
A paraneoplastic syndrome is a symptom that is the consequence of the presence of cancer in the body but is not due to the local presence of cancer cells.
It is mediated by hormones or cytokines excreted by cancer cells or by an immune response against cancer.
What is hypocalcemia and when does it occur
Occurs when there is a net efflux of calcium from the ECF and may be seen in malignant disease, rhabdomyolysis, acute pancreatitis, sepsis, shock and in chronic renal disease.
Signs and symptoms of hypocalcemia
paraesthesia, muscle cramps, laryngospasm, tetany and seizures. Cardiac manifestations may include a prolonged QT interval which may progress to VT or heart block
What are the treatment options available for hypocalcemia
Treatment is cause specific. Fluid, acid-base and other electrolytes are managed - supplements either oral or parenteral can be employed.
