Parathyroid Flashcards
What is the function of the parathyroid gland?
controls calcium level in the body
What are the inferior parathyroid glands derived from?
3rd branchial
What is the blood supply & venous drainage of the parathyroid gland?
inferior thyroid artery
superior, middle, & posterior thyroid veins into internal jugular
What is the function of PTH?
- conversion of calcidiol to calcitriol in renal tubular cells
- increase calcium absorption from intestine
- increase calcium resorption from the bone
- calcitriol feeds back to inhibit PTH secretion
- calcitonin secreted by parafollicular thyroid cells opposes it
What are the causes of primary hyperparathyroidism?
- exposure to low-dose therapeutic ionizing radiation
- renal leak calcium
- decline in renal function by aging
- alteration in the sensitivity of gland for suppression by calcium
- lithium use
PRESENTS AS:
adenoma
hyperplasia
carcinoma
what are the causes of secondary hyperparathyroidism?
- renal failure
- inadequate calcium intake
- inadequate calcium absorption (vitamin D deficiency)
- GI diseases causing malabsorption
What are the causes of tertiary hyperparathyroidism?
further stage in the development of reactive hyperplasia where autonomy occurs as parathyroid gland doesnt respond to physiological stimuli
AFTER RENAL TRANSPLANT
what is the presentation of a patient with hyperparathyroidism?
- asymptomatic
- kidney stones
- painful bones
- abdominal groans
- psychic moans
- fatigue overtones
- muscular weakness
- proximal neuropathy
- gout & pseudogout
- calcification at ectopic site
- increase death from cardiovascular disease
how can hyperparathyroidism cause RENAL DISEASE?
- renal stone
- nephrocalcinosis
- chronic hypercalcemia leads to polyurea, polydipsiea, & nocturia
- hypertension
how can hyperparathyroidism cause BONE DISEASE?
- osteopenia, osteoporosis, & osteitis fibrosa cystica
- brown or osteoclastic tumors & bone cysts
- severe bone disease results in severe pain, tenderness, & pathological fractures
How can hyperparathyroidism cause GIT COMPLICATIONS?
- peptic ulcer disease
- pancreatitis if Ca > 12.5
- cholelithiasis
What NEUROPSYCHIATRIC COMPLICATIONS does hyperparathyroidism cause?
- psychosis
- obtundation
- coma
- depression, anxiety, fatigue
What could hyperparathyroidism be confused with?
- malignancy
- familial hypocalciuric hypercalcemia
- thiazide, lithium use
What investigations should be done for a suspected case of hyperparathyroidism?
- calcium level
- PTH
- vitamin D
- magnesium balance
- acid base balance
- 24-h urine for calcium level
What are the investigations used for diagnosis?
ULTRASOUND neck
CT scan of neck
MRI
99mTc-labeled sestamibi scan
