Parathyroid Path- Krafts Flashcards
What cells are responsible for production of Parathyroid Hormone secretion?
Chief cells of the parathyroid Glands
Where do the parathyroid glands originate from?
The top pair from 4th pharyngeal pouch
Lower pair arises from 3rd pharyngeal pouch
What do oxyphil cells look like?
Scattered clusters of big cell with pink cytoplasm
Increase with age and have no function
Two cells found in the parathyroid glands
Chief cells - secrete PTH
Oxyphil
What are the 3 causes of primary hyperparathyroidism?
Parathyroid Adenoma
Parathyroid Hyperplasia
Parathyroid Carcinoma
What does the “stone, bone, moan, groan” disease refer to?
Hyperparathyroidism
Stone- kidney stones
Bone- bone pain, osteoclasts erode bone
Groan- constipation
Moan- mental changes
What is osteitis fibrosa cystica?
due to long standing high PTH
Cystic bone spaces filled with brown fibrous tissue
Can you tell parathyroid hyperplasia from parathyroid adenoma microscopically?
Nope!!!
Grossly - adenoma usually involves one gland,
Hyperplasia usually involves all 4 glands
Why do you see increased urinary cAMP?
PTH acts through a Gs receptor - activates adenylate cyclase - increased conversion of ATP to cAMP
When acting on renal tubules, increased cAMP can spill over into urine
Why do you see increased alkaline phosphatase (ALP)?
Sign of osteoblast activity - need alkaline environment to build bone
PTH originally stimulates the osteoblasts - which they then stimulate osteoclasts
What is secondary hyperparathyroidism?
Hyperparathyroidism due to chronic hypocalcemia
What usually causes secondary hyperparathryoidism?
Renal Failure causing hypocalcemia and hyperphosphatemia
Causes of hypoparathyroidism
Autoimmune syndrome
Surgical excision
DiGeorge Syndrome
What is DiGeorge Syndrome?
Failure of the 3rd and 4th pharyngeal pouches to form
Signs of hypoparathyroidism?
Low PTH
Low serum Ca
Numbness and tingling
Muscle Spasms/Tetany
