Calcium and Parathyroid Flashcards Preview

Endocrine > Calcium and Parathyroid > Flashcards

Flashcards in Calcium and Parathyroid Deck (30)
Loading flashcards...
1
Q

When Ca receptors on PTgland sense low calcium, what happens

A

increase in parathyroid hormone release –> will increase renal calcium absorption and increased bone resorption/release of calcium, increase formation of active form of VitD

2
Q

Vitamin D hydroxylation

A

2 hydroxylations: 1st in liver, 2nd in kidney (second hydroxylation stimulated by PTH)

3
Q

Calcitriol/Vitamin D

A

increases calcium absorption in gut –> increase serum calcium

4
Q

Hyperparathyroidism

A

“bones, groans, stones, and psychic moans” –> abnormal PTH hypersecretion –> hypercalcemia

5
Q

Most primary hyperthyroidism is caused by

A

solitary (single PT) adenoma (85%), diffuse hyperplasia (15%), parathyroid carcinoma <1%

6
Q

T/F in pt adenoma, may have hypertrophy of other pt glands

A

F –> atrophy b/c of negative feedback from high calcium due to hyperactive pt

7
Q

hypercalcemia can lead to increase/decrease in ECF phosphate

A

decrease –> increased urinary phosphate is an effect of pth and overrides the phosphate released from bone with calcium

8
Q

Groans

A

increased PTH can increase bp, constipation, GI tone

9
Q

Classical presentation of primary hyperparthyroidism

A

osteitis fibrosa cystica –> bone demineralization with subperiosteal bone resorption and bone cysts

10
Q

Realistic presentation of primary hyperparathyroidism

A

elevated serum calcium, kidney stones, renal dysfunction, reduced bone mineral density (cortical bone)

11
Q

Tx of hyperparathyroidism

A

asymptomatic: medical monitoring // surgery for kidney stones, fracture in symptomatic patients or asymptomatic patients<50 years with severe hypercalcemia or reduced creatinine clearance or low bone mass

12
Q

Secondary hyperparathyroidism

A

hyperfunctioning Pt glands are compensating for hypocalcemia: renal insufficiency, calcium malabsorption, vitamin D deficiency

13
Q

Tertiary hyperparathyroidism

A

gland hyperfunction and hypersecretion due to prolonged secondary hyperparathyroidism –> gland autonomy –> elevated calcium, requires surgery

14
Q

Familial hypocalciuric hypercalcemia

A

autosomal dominant –> looks like primary hyperparathyroidism –> abnormal calcium sensor –> increase in calcium setpoint –> increased pth secretion –> elevated calcium –> low urine calcium

15
Q

Difference between FHH and Primary hyperparathyroidism

A

low urine calcium in FHH –> calcium sensor in kidney also broken –> cannot flush out calcium

16
Q

Hypoparathyroidism

A

following total thyroidectomy or radical neck dissection, infiltrative (hemochromatosis or wilson’s), congenital (digeorge, familial type 1 polyendocrine)

17
Q

Hypocalcemia effects

A

cardiac arrhythmia, neuromuscular irritability/tetany

18
Q

Chvostek sign

A

irritable facial nerve due to hypocalcemia

19
Q

Trousessau’s sign

A

carpal spasm due to hypocalcemia

20
Q

Trousseau or Chvostek is more specific

A

Trousseau –> but takes a whole 3 minutes in the clinic

21
Q

Tx of hypoparathyroidism

A

oral calcium, vitamin D,monitoring urinary/serum calcium,

22
Q

Goal is serum calcium level in patient with hypoparahtyroidism

A

low normal –> will lose a lot of calcium in the urine b/c of absence of pth –> want to avoid kidney stones so go low normal

23
Q

Vitamin D intoxication

A

uncommon cause of hypercalcemia –> nausea, vomiting, weakness, AMS

24
Q

sequelae of Vitamin D intoxication

A

stored in fat –> cannot chelate it –> prolonged hypercalcemia

25
Q

Tx of D intoxication

A

hydration, no dietary calcium

26
Q

Vitamin D deficiency

A

lack of sun, decreased intake/absorption of vitamin D, metabolic defects in vitamin D hormone system –> leads to secondary hyperparathyroidism

27
Q

Sequelae of vitamin d deficiency

A

rickets in children, osteomalacia in adults –> widened osteoid (demineralized bone) seams and impaired mineralization, risk of osteoporosis

28
Q

_______ is important in mineralization of devoid bone matrix to lay down calcium.

A

Vitamin D

29
Q

Characteristic signs of osteomalaci

A

diffuse bone pain and tenderness, proximal muscle weakness, Looser-Milkman pseudofractures perpendicular to bone surface

30
Q

Tx of Vitamin D deficiency

A

treat underlying disorder, calcium, vitamin D