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25 Cards in this Set
- Front
- Back
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___ acts to increase serum Ca++ levels,
___ acts to decrease serum Ca++ levels. |
Parathyroid hormone (PTH) acts to increase Ca++ levels
Calcitonin acts to decrease Ca++ levels |
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Effects of PTH
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o incr. Ca2+ and $PO43- reabsorption in the kidney,
o incr. osteoclast activity and o incr. 1,25 dihydroxy vitamin D3 (calcitrol, the hormonally active form of vitamin D) production in the kidney, thereby stimulating intestinal calcium absorption. Overall it leads to plasma incr. Ca2+ and decr. PO43 |
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Normal serum PTH conc.
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10-65mg/dL
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Primary hyperparathyroidism
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Elevated serum PTH caused directly by increased production by one or more parathyroid gland.
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Secondary hyperparathyroidism
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Increased PTH in response to impaired renal calcium reabsorption, reduced vitamin D3 synthesis and malabsorption of dietary calcium.
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Tertiary hyperparathyroidism
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Occurs when long standing secondary hyperparathyroidism is corrected
Prolonged stimulation of the parathyroid glands causes desensitisation and loss of negative feedback response to high calcium levels. |
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Symptoms of primary hyperparathyroidism
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Symptoms of hypercalcemia: Bones, Stones, psychosis-based Moans, and abdominal Groans
arrhythmias, hypotonia, bone pain, cognitive changes, abdominal pain |
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What % of primary hyperparathyroidism cases are symptomatic?
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50%
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Tx for primary hyperparathyroidism
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1. Surgical excision - if severe
2. Medications - if mild or surgery not an option - calcitonin, - bisphosphonates, - diuretics, AND - rehydration |
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Blood test results for primary hyperparathyroidism show
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incr serum Ca2+
decr PO4 incr PTH incr ALP incr 24h urine Ca2+ |
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Effect of bisphosphonates
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Prevent loss of bone mass
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Blood test results in secondary hyperparathyroidism
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low/normal Ca2+
incr PO4 incr PTH incr ALP incr creatinine |
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Tx for secondary hyperparathyroidism
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- Treat underlying CRF
- Treat hypocalcaemia if present (with calcium supplementation) - Decrease phosphate (decrease dietary intake and use PO4 binders) - Give vitamin D analogues |
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Blood test results in tertiary hyperparathyroidism
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incr Ca2+
incr PO4 incr PTH incr ALP incr creatinine |
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Tx for tertiary hyperparathyroidism
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Surgically remove three and a half parathyroid glands
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What are the 2 types of hypoparathyroidism?
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Primary hypoparathyroidism
Pseudohypoparathyroidism |
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Primary hypoparathyroidism
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resulting from decreased secretion and gland failure
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Pseudohypoparathyroidism
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failure of the target cells to respond to PTH
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Symptoms of hypoparathyroidism (5)
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Symptoms of hypocalcemia
paraesthesias, hyperreflexia, tetany, confusion, psychosis. |
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Blood test results in primary hypoparathyroidism
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decr Ca2
incr/normal PO4 normal ALP decr PTH |
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Blood test results in pseudohypoparathyroidism
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decr Ca2
incr/normal PO4 normal ALP incr PTH |
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Tx for hypoparathyroidism
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Vitamin D analogue and calcium
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Name a vitamin D analog
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alfacalcidol
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Where is vitamin D turned into 1,25-dihydroxycholecalciferol
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kidneys
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What produces calcitonin
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the thyroid glands
NOT parathyroid glands |
