Tissue Mineralization Flashcards
What is mineralization in the context of cell degeneration
Pathogenic, caused by a deposition of Ca
What are the two types of mineralization
Dystrophic
Metastatic
What causes dystrophic mineralization
Ca deposition due to dysregulation at the local level
What are the Ca blood levels in dystrophic mineralization
Normal
What causes metastatic mineralization
Ca deposition due to systemic dysregulation
What are the Ca blood levels in metastatic mineralization
High (hypercalcemia)
Is the morphology the same for metastatic and dystrophic mineralization?
Yes
Gross morphology
Tissue is white/tan and feels gritty/chalky
Histo morphology
H & E: granular, basophilic material
Von kossa: brown-black
How does dystrophic mineralization happen
Necrotic cells can’t regulate cytosolic Ca levels
Ca is deposited in the dead/dying tissue
How does the blood regulate Ca when levels are high
Parafollicular cells in thyroid increase calcitonin –> osteoblasts sequester Ca
Parathyroid decreases PTH secretion –> no Ca released from bones
How does the blood regulate Ca when levels are low
Parafollicular cells decrease calcitonin secretion
PTH secretion is increased –> Ca released from bones and kidneys secrete calcitriol –> more Ca absorption
How is vitamin D involved in Ca regulation
Produces calcidiol which stimulates kidneys to upregulate calcitriol which leads to increased Ca absorption
What are the mechanisms of hypercalcemia
Primary hyperthyroidism
Hypercalcemia of malignancy
Vit D toxicosis
Renal failure
Bone destruction
Primary hyperthyroidism -
Caused by neoplasms of the thyroid gland
Secretes increased PTH
