parathyroid

Question 1

avg weight 1 parathyroid gland

Answer 1

25-50 mg

Question 2

color of normal parathyroid

Answer 2

yellow

Question 3

red brown parathryoid gland

Answer 3

adenoma

Question 4

2 cell types in parathyroid gland

Answer 4

chief cells and oxyphil cells

Question 5

why are oxyphil cells pink

Answer 5

lots of mitochondria

Question 6

function of parathyroid gland

Answer 6

regulate calcium homeostasis

Question 7

how do PTH glands regulate Ca

Answer 7

icnrease renal tubular resorption of Ca
increase conversion of Vit D to active form in kidneys
increase urinary PO4 lowering serum PO4
change GI Ca absorption

Question 8

what is primary hyperPTH

Answer 8

autonomous overproduction of PTH usually resulting from adenoma or hyperplasia of PTH tissue

Question 9

what is secondary hyper PTH

Answer 9

compensatory hypersecretion of OTH in response to prolonged hypoCa, usually from chronic renal failure

Question 10

what is tertiary hyper PTH

Answer 10

persistent hypersecretion of PTH even after the cause of prolonged hypoCa is corrected
(e.g after renal transplant)

Question 11

3 most common causes of primary hyper PTH

Answer 11

pituitary adenoma
primary hyperplasia (diffuse or nodular)
PTH carcinoma

Question 12

microscopic PTH adenoma

Answer 12

uniform polygonal chief cells with small central nuclei

Question 13

what type of PTH adenoma resemble hurthle cell changes

Answer 13

oxyphil adenomas

Question 14

what is endocrine atypia

Answer 14

pleomorphic nuclei in adenomas

Question 15

histo of PTH adenoma

Answer 15

no fat, thin rim of normal PTH (has fat globules)

Question 16

most common cause primary hyeprPTH

Answer 16

solitary PTH adenoma arising sporadically

Question 17

how is hyper PTH detected usually

Answer 17

first incidental finding of hyeprCa

Question 18

genetic syndromes assoc with familial PTH adenomas

Answer 18

MEN 1 and 2

germline mutations in MEN1 and RET

Question 19

bone Sx of hyperPTH

Answer 19

osteoporosis, brown tumors, osteitis fibrosa cystica

Question 20

osteoclasts in hyperPTH affect what bone type more than medullary bone

Answer 20

cortical (subperiosteal and endosteal surfaces)

Question 21

what is dissecting osteitis

Answer 21

when osteoclasts in medullary bone dissect centrally along the trabeculae creating appearance of railroad tracks

Question 22

What is osteitis fibrosa cystica

Answer 22

von Recklinghausen disease of bone

increased osteoclast activty, peritrabecular fibrosis and cystic brownt tumors

Question 23

what is a cystic brown tumor in bone from

Answer 23

loss of bone causes microfractures, hemorrhage and influx of macrophages that cause reparative fibrous tissue and reactive tissue i.e. brown tumor

Question 24

how does hyper PTH affect renal system

Answer 24

nephrolithiasis and nephrocalcinosis

met calcification can occur in stomach lungs myocardium and blood from hyperCa

Question 25

most common cause asymptomatic hyper Ca

Answer 25

primary hyperPTH

Question 26

cause of symptomatic hyperCa in adults

Answer 26

malignancy: solid tumors like lung, breast, head and neck and renal cancers multiple myeloma

Question 27

mech in which osteolytic tumors induce hyperCa

Answer 27

secretion of PTH related peptide PTHrP

Question 28

Causes of hyper Ca with decreased PTH levels too

Answer 28

``` hyperCa of malignancy Vit D toxicity immobilization thiazide diuretics granulomatous disease (sarcoidosis) ```

Question 29

painful bones, renal stones, abdominal groans and psychic moans

Answer 29

primary hyperPTH

Question 30

Abdominal Sx from primary hyper PTH

Answer 30

nausea, vomiting, constipation, indigestion

Question 31

effects of hyperPTH on nervous system

Answer 31

lethargy, fatigue, memory loss, psychosis, depression

Question 32

most common cause secondary hyper PTH

Answer 32

renal failure

Question 33

what occurs in secondary hyper PTH

Answer 33

chronic hypocalcemia that leads to compensatory overactivity of the PTH glands

Question 34

kimmelstein wilson glomeruli

Answer 34

DM and nodular glomerulosclerosis

Question 35

what other diseases can cause secondary hyper PTH

Answer 35

inadequate dietary intake of Ca, steatorrhea, vit D deficiency

Question 36

morphology of PTH glands d/t secondary hyperPTH

Answer 36

all 4 glands enlarged hyperplastic with increased chief cells and abundant clear cytoplasm fat cells are decreased in number

Question 37

secondary hyperPTH has met calcificaitons where

Answer 37

lungs, heart stomach and blood vessels

Question 38

what is calicphylaxis

Answer 38

vascular calcification assoc with secondary hyper PTH from ischemic damage to skin and other organs

Question 39

what do you Tx patients with secondary hyperPTH

Answer 39

dietary vit D supp | phosphate binders which dec the hyperphosphatemia

Question 40

what is tertiary hyperPTH

Answer 40

autonomous and excessive with resultant hyperCa

Question 41

Tx tertiary hyperPTH

Answer 41

parathyroidectomy

Question 42

acquire hypoPTH is usually a consequence of

Answer 42

surgery

Question 43

PTH glands are mistaken for what

Answer 43

lymph nodes

Question 44

what is autoimmune hypoPTH

Answer 44

chronic mucocutaneous candidiasis and primary adrenal insufficiency autoimmune polyendocrine syndrome type 1

Question 45

what mutations cause autoimmune polyendocrine syndrome type 1

Answer 45

autoimmune regulator gene

Question 46

how does autoimmune hypoPTH present

Answer 46

candidiasis in childhoos followed by hypoPTH and adrenal insufficiency in adolescence

Question 47

what is autosomal dominant hypoPTH caused by

Answer 47

gain of function mutations in Ca sensing R gene | results in hypocalcemia and hypercaliuria

Question 48

What is familial isolated hypoPTH

Answer 48

FIH rare condition with auto dom or auto recessive patterns

Question 49

What causes auto dom FIH (familial isolated hypoPTH)

Answer 49

mutation in gene encoding PTH precursor peptide which impairs its processing to the mature hormone

Question 50

What causes auto recessive FIH(familial isolated hypoPTH)

Answer 50

loss of function mutations in transcription factor gene glial-cells-missing-2 GCM2 which is needed for development of parathyroid

Question 51

what can cause congenital absence of PTH glands

Answer 51

thymic aplasia, CV defects | 22q11 deletion syndrome(digeorge)

Question 52

hallmark clinical features hypoPTH

Answer 52

tetany with neuromuscular irritability (Decreased serum Ca levels) circumoral numbness, parasthesias of distal extremities and carpopedal spasm to life threatening laryngospasm and generalized seizures

Question 53

What is a Chvostek sign

Answer 53

tap along facial nerve to induce contractions of the muscles of the eye mouth or nose

Question 54

What is a Trousseau sign

Answer 54

carpal spasms produced by occlusion of the circulation to the forearm and hand with a bp cuff for several minutes

Question 55

other clinical features to hypoPTH

Answer 55

mental status changes like emotional instability and anxiety intracranial manifestations like calcifications of basal ganglia ocular- calcification of lens and cataract CV manifestations- long QT dental- dental hypoplasia, failure eruption, defective enamel and root formation

Question 56

what causes the intracranial manifestations of hypoPTH

Answer 56

increased phosphate levels resulting in tissue deposits with Ca that exists in local extracellular milieu

Question 57

what causes pseudohypoPTH

Answer 57

end-organ Resistance to the actions of PTH

Question 58

how does pseudohypoPTH present

Answer 58

hypoCa, hyperphosphatemia, elevated circulating PTH

Question 59

signs of pseudohypoPTH

Answer 59

+chvosteks and trousseaus short stature and short fingers increased PTH mental retardation