Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
25 Cards in this Set
- Front
- Back
___ 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 |
|
Effects of PTH
|
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 |
|
Normal serum PTH conc.
|
10-65mg/dL
|
|
Primary hyperparathyroidism
|
Elevated serum PTH caused directly by increased production by one or more parathyroid gland.
|
|
Secondary hyperparathyroidism
|
Increased PTH in response to impaired renal calcium reabsorption, reduced vitamin D3 synthesis and malabsorption of dietary calcium.
|
|
Tertiary hyperparathyroidism
|
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. |
|
Symptoms of primary hyperparathyroidism
|
Symptoms of hypercalcemia: Bones, Stones, psychosis-based Moans, and abdominal Groans
arrhythmias, hypotonia, bone pain, cognitive changes, abdominal pain |
|
What % of primary hyperparathyroidism cases are symptomatic?
|
50%
|
|
Tx for primary hyperparathyroidism
|
1. Surgical excision - if severe
2. Medications - if mild or surgery not an option - calcitonin, - bisphosphonates, - diuretics, AND - rehydration |
|
Blood test results for primary hyperparathyroidism show
|
incr serum Ca2+
decr PO4 incr PTH incr ALP incr 24h urine Ca2+ |
|
Effect of bisphosphonates
|
Prevent loss of bone mass
|
|
Blood test results in secondary hyperparathyroidism
|
low/normal Ca2+
incr PO4 incr PTH incr ALP incr creatinine |
|
Tx for secondary hyperparathyroidism
|
- Treat underlying CRF
- Treat hypocalcaemia if present (with calcium supplementation) - Decrease phosphate (decrease dietary intake and use PO4 binders) - Give vitamin D analogues |
|
Blood test results in tertiary hyperparathyroidism
|
incr Ca2+
incr PO4 incr PTH incr ALP incr creatinine |
|
Tx for tertiary hyperparathyroidism
|
Surgically remove three and a half parathyroid glands
|
|
What are the 2 types of hypoparathyroidism?
|
Primary hypoparathyroidism
Pseudohypoparathyroidism |
|
Primary hypoparathyroidism
|
resulting from decreased secretion and gland failure
|
|
Pseudohypoparathyroidism
|
failure of the target cells to respond to PTH
|
|
Symptoms of hypoparathyroidism (5)
|
Symptoms of hypocalcemia
paraesthesias, hyperreflexia, tetany, confusion, psychosis. |
|
Blood test results in primary hypoparathyroidism
|
decr Ca2
incr/normal PO4 normal ALP decr PTH |
|
Blood test results in pseudohypoparathyroidism
|
decr Ca2
incr/normal PO4 normal ALP incr PTH |
|
Tx for hypoparathyroidism
|
Vitamin D analogue and calcium
|
|
Name a vitamin D analog
|
alfacalcidol
|
|
Where is vitamin D turned into 1,25-dihydroxycholecalciferol
|
kidneys
|
|
What produces calcitonin
|
the thyroid glands
NOT parathyroid glands |