thyroid and parathyroid Flashcards Preview

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Flashcards in thyroid and parathyroid Deck (39):
1

what stimulates the parathyroid glands to release PTH

low serum calcium

2

what form of calcium is sensed?

ionized calcium

3

where does the increase in calcium come from?

the bone, intestine, and kidney

4

how does the kidney respond to PTH?

it increases its secretion of phosphate, retains calcium, produces 1, 25 hydroxyvit D, which stimulates the intestinal absorption.

5

how does VIt D increase calcium?

stimulates intestinal absorption and stimulates osteoclasts.

6

how is vit D regulated?

tightly, through the action of calcium, PTH and phosphorus

7

what are the most common causes of hypercalcemia?

hyperparathyroidism and malignancy

8

what is the first step in diagnosing hyperthyroidism

PTH levels! always first

9

PTH levels in primary hyperparathyroid?

high or normal

10

primary hyperparathyroidism characteristics and statistics ?

3:1 women, more common when 60. typically caused by hyper secretion in one or more glands. solitary adenoma 80% of the time. less common that all glands are hypertrophied.

11

how is primary hyperPT diagnosed on labs?

elevated calcium, elevated or normal PTH, low phosphorus, elevated urine calcium.

12

secondary hyperPT characteristics

perceived low calcium concentration. can occur in renal disease due to phosphate retention and lack of 1-alpha hydroxylase activity in the kidney thus a deficiency of activated Vit D.

13

how does high phosphorus effect the PTH system?

it will stimulate PTH secretion

14

what do you have to prescribe sometimes in renal disease, due to phosphorus and why?

low phosphate diet, phosphate binders, replacement of activated Vit D and dialysis.

15

can vitamin D deficiency cause hyperPT

yes. very common actually. need to replace sometimes.

16

tertiary hyperPTism characteristics and causes

PT becomes autonomous after prolonged hyperPTism. this is similar to primary, in that the gland is hyper secreting. this is different from secondary in the sense that the calcium in high, not low.

17

hypocalcemia characteristics

the PTH levels will be high in effort to counteract. can be caused by destruction of the parathyroid, or failure to produce. characterized by the level of PTH

18

hypoPTism

PTH produced is insufficient to meet demands or is unable to function properly. usually there is a low serum calcium and low PTH.

19

pseudohypoPTism

similar to hypo but the PTH is elevated. there is a resistant state.

20

thyroid disease characteristics and demographics

most prevalent endocrine disorder. usually a slow and insidious process, often vague symptoms not understood by the patient. often misdiagnosed.

21

hypothyroid

failure to secrete adequate amounts of hormone.

22

primary hypothyroid

destruction of the thyroid or interference with hormone synthesis.

23

secondary hypothyroid

hypothalamic or pituitary disease.

24

labs for primary hypothyroidism

high TSH, low T4

25

labs for secondary hypothyroid

T4 low but TSH low or normal.

26

common causes of primary hypothyroidism

hashimotos. idiopathic (usually old hash), irradiation of the thyroid, surgical removal, fibrous thyroiditis, iodine deficiency, drug therapy, infiltrative diseases

27

causes of secondary hypothyroid

pituitary or hypothalamic tumor, congenital hypopituitarism, pituitary necrosis

28

hypothyroid face?

apathetic facies, lack of eyebrows, bilateral ptosis.

29

risk factors for hypothyroid

age (men > 60, women >35), sex (female), goiter, history of thyroid dysfunction, family history, head/neck/thyroid surgery, autoimmune disease, drug, hypercholesterolemia

30

treatment for hypothyroid

levothyroxine aiming to normalize TSH.

31

hyperthyroidism

hyper metabolic state caused by increased availability of hormone.

32

clinical features of hyperthyroid

nervousness, irritability, sweating, goiter, rapid HR, bulging eyes, warm moist palms, infertility, weight loss, first-trimester miscarriage. difficulty sleeping.

33

causes of hyperthyroidism

diffuse toxic goiter (graves), diffuse multinodular goiter, toxic adenoma.

34

Graves

autoimmune disorder, favors women 8:1, thyroid stimulating antibodies to the TSH receptor causes hypertrophy and hyper secretion.

35

ophthalmic disorder graves

true infiltrative eye disease, results in periorbital edema, conjunctival swelling and congestion, limited upward and lateral gaze, keratitis.

36

acute/subacute thyroiditis

viral or bacterial etiology

37

De Quervains subacute thyroiditis

lymphocytic (painless, subacute), post-partum thyroiditis,

38

labs for primary hyperthyroid

suppressed TSH levels, high T4 and T3. increased radioactive iodine uptake.

39

which forms of iodine are used to image the thyroid?

I123, I131.