Pathology Part II Flashcards
These cells regulate free ionized calcium via PTH
Chief cells (of the parathyroid)
How to do chief cells regulate ionized calcium?
- increase bone osteoclast activity - releasing Ca and Phosphate
- Increase small bowel absorption of calcium and phosphate (indirect vit D activation)
- Increase renal calcium reabsorption (distal tubule) and decrease phosphate reabsorption (proximal tubule)
Increased serum calcium provides this type of feedback to the parathyroid
Negative.
Increased serum Ca leads to a decrease in PTH secretion.
Define primary hyperparathyroidism
Excess PTH due to a disorder of the parathyroid gland itself
Most common cause of hyperparathyroidism?
Parathyroid adenoma (80%)
Sporadic parathyroid hyperplasia
parathyroid carcinoma
How do parathyroid adenomas most often present?
benign hypercalcemia
Laboratory findings of hyperparathyroidism?
increased PTH increased Ca decreased Phos. Increased urinary cAMP increase serum alk phos
Most common cause of secondary hyperparathyroidism?
Chronic renal failure
Pathophysiology of CRF and secondary hyperparathyroidism?
Renal insufficiency - decreased phosphate excretion
Increased serum phosphate - binds free Ca
Decreased free Ca stimulates parathyroid glands
Increased parathyroid gland activity stimulates bone resorption
Lab findings of secondary hyperparathyroidism?
Increased PTH
decreased Ca
increased serum phos
increased alk phos
What differences in lab findings will you see between primary and secondary hyperparathyroidism?
Primary: Increased Ca, decreased phosphate
secondary: decreased Ca, increased phosphate
List some causes of hypoparathyroidism
Autoimmune damage
surgical excision
Di George syndrome
How do symptoms of low serum calcium often present?
Numbness and tingling
Muscle spasm
Lab results of hypoparathyroidism
Low PTH
Low serum calcium
End organ resistance to PTH (high PTH levels)
Pseudohypoparathyroidism
The endocrine pancreas is composed of these types of cells
Islet cell cluster
B cells - insulin
A cells - glucagon
Insulin MOA
upregulates insulin dependent glucose transporter protein (GLUT4) on skeletal muscle and adipose tissue
Type I diabetes HLA
DR3 and DR4
Etiology of CV disease among diabetics
Nonenzymatic glycosylation (NEG) of vascular membranes
What number measures the NEG of Hgb (glycated Hgb)
HbA1C
Pancreatic endocrine neoplasms often are a component of this endocrine syndrome
MEN 1
along with Parathyroid hyperplasia and pituitary adenoma
Lab values in pt with insulinoma
Decreased serum glucose
Increased insulin
increased C peptide
Three layers of adrenal cortex and the hormones they produce
Glomerulosa - mineralocorticoids
Fasciculata - glucocorticoids
Reticularis - androgens
What are all steroid hormones derived from
Cholesterol
Primary hyperaldosteronism is most commonly due to this condition
Bilateral adrenal hyperplasia
Tx for primary hyperaldosteronism
mineralocorticoid receptor antagonist such as spironolactone or eplerenone
if adenoma – surgically resect
Classical presentation for hyperaldosteronism?
HTN
Hypokalemia
metabolic alkalosis
How will Liddle syndrome vary from hyperaldosteronism when running tests
Will have LOW aldosterone
