Calcium and Parathyroid Flashcards Preview

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Flashcards in Calcium and Parathyroid Deck (25)

What do calcium sensing receptors do?

Sense low calcium and then stimulate production of PTH


On which organs does PTH act?

Bone: Stimulates Ca resorption
Kidney: Stimulates Ca reabsorption
Gut: Via raising 1,25 (OH)VitD, stimulates Ca absorption


What is main result of hyperparathyroidism?



What are leading causes of primary hypercalcemia?

Solitary adenoma: 85%
Diffuse hyperplasia: 15%
Parathyroid carcinoma:


What is net result of PTH on phosphate?

Lowers phosphate-- although it raises phosphate resorption from bone, this is "trumped" by increased phosphate excretion in kidney


What are signs of hyperparathyroidism in following areas:

GI (3)
CVS (1)
Bone (2)
Brain (2)

GI: pancreatitis, stomach ulcers, kidney stones
CVS: High BP
Bone: osteitis fibrosa cystica, low BMD in cortical bone
Brain: Depression/psychosis


What criteria constitute a "symptomatic patient" for hyperparathyroidism? (2) What is treatment mainstay?

Symptomatic patient displays kidney stones or a fracture

Treatment would be surgical


What are criteria for asymptomatic hyperparathyroid patient that requires surgery? (4)

Age 1 above upper limit of lab value
Low creatinine levels


Describe histologic appearance of parathyroid adenoma

Lots of normal-looking parathyroid cells in well-encapsulated adenoma


Describe secondary hyperparathyroidism. What are underlying causes? (3)

In secondary hyper functioning parathyroid glands compensate for hypoglycemia

Treatment is to address underlying cause:
Renal insufficiency (no 1,25(OH)VitD)
Calcium malabsorption
Vitamin D Deficiency


What is tertiary hyperparathyroidism? What is the treatment?

Hyperfunctioning parathyroid gland and hyper secretion due to prolonged secondary hyperparathyroidism.

Treat with surgery if severe.


What is familial hypocalciuric hypercalcemia?

What are the lab findings?

Autosomal dominant mutation in Calcium-Sensing receptor leading to shift in parathyroid set point for calcium.

Lab findings: Elevated serum Ca with low urine calcium and normal PTH


What is treatment for familial hypocalciuric hypercalcemia?

Nah it's benign


What are three categories of hypoparathyroidism causes?

Name an example of each.

Post-surgical (thyroidectomy)
Infiltrative disease: hemochromatosis, wilson's disease
Congenital: DiGeorge syndrome, autosomal polyglandular syndrome type 1


What are symptoms of hypoparathyroidism?

What are big signs?

Cardiac arrhythmia
Neuromuscular irritability: perioral, tingling of fingers/toes, tetany
Signs: Chvostek's sign (ipsilateral lip twitch on tapping), Trousseau's sign (carpal spasm)


What is treatment for hypoparathyroidism? What do you monitor?

Rx: Oral calcium and 1,25 (OH)VitD
Monitor: Serum/urine calcium levels


What is goal serum calcium level for hypoparathyroidism? Why?

Low normal-- if too much calcium most will be excreted by kidneys, but this runs risk of kidney stone


Vitamin D intoxication: What are symptoms (4)and lab sign?

VitaminD intoxification requires large doses-- it results in nausea, vomiting, weakness and altered mental status.

It results in prolonged hypercalcemia


What is the treatment for Vitamin D intoxication? (2)

Hydration, no dietary calcium


What is the etiology of vitamin D deficiency? (3)

What does it lead to?

Lack of solar irradiation
Decreased intake or impaired absorption
Metabolic defects in VitD hormone system-- inadequate activation in liver/kidney, abnormalities of VitD-receptor

Leads to secondary hyperparathyroidism


How is vitamin D deficiency treated?

Vitamin D intake

Vitamin D enriched foods-- milk, cheese, fish, eggs


What are metabolic bone diseases associated with vitamin D deficiency? (2) In which populations are they most common

Rickets in children
Osteomalacia in adults


What is the main result of rickets in relation to bone? What are some signs? (2)

Lack of mineralization of bones.

Bowing of legs and metaphyseal cupping/fraying


What is the clinical presentation of osteomalacia?

Usually asymptomatic
Symptoms: diffuse pain and tenderness, proximal muscle weakness


What is treatment for vitamin D deficiency?

Treat underlying disorder
Correct hypoglycemia and vitamin D deficiency