Calcium, phosphate, and magnesium Flashcards
The majority of magnesium is lost/absorbed at what part of the nephron?
Thick ascending limb of the loop of Henle
The majority of calcium and phosphate is lost/absorbed at what part of the nephron?
Proximal convoluted tubule
How does pH effect calcium concentration?
Alkolosis –> Decreases calcium
Acidosis –> Increases calcium
What are common causes of hypocalcaemia?
Chronic and acute renal failure Vitamin D deficiency Hypoparathyroidism (Usually surgical) Acute pancreatitis Magnesium deficiency
What does deficiency of active vitamin D result in?
In children –> Rickets
In adults –> Osteomalacia
What is a carpopedal spasm?
When reduced ionized calcium and phosphate levels cause a involuntary contraction of the feet or (more commonly) the hands.
What is Trousseau’s sign?
Inward flexion of the hand when a blood pressure cuff occludes the brachial artery.
A more sensitive sign for low calcium.
What are the causes of hypercalcaemia?
Primary hyperparathyroidism (Increased PTH) Malignancy (low PTH)
What are the different types of hyperparathyroidism?
1) Primary (Increased secretion of PTH)
- -> Single or multiple adenoma (common)
- -> Parathyroid hyperplasia (less common)
- -> Parathyroid carcinoma (rare)
2) Secondary
- -> Renal failure (Failure of 1-hydroxylation)
- -> Vitamin D deficiency (Failure to absorb Ca2+)
3) Tertiary
- -> Prolonged secondary hyperparathyroidism
- -> Renal transplantation
What is Gitelman syndrome?
A kidney disorder that causes an imbalance of charged atoms (ions) in the body, including ions of potassium, magnesium, and calcium. MAINLY MAGNESIUM.
Caused by a mutation in the SLC12A3 gene that encodes the sodium-chloride cotransporter ( NCCl),
which is expressed in the DCT.
What are some causes of magnesium excess?
Acute renal failure (not diuretic phase)
Severe diabetic ketoacidosis
Addison’s disease
Supplements
