Thyroid Disease

Question 1

what’s the major secretory cell of the thyroid gland?

Answer 1

follicular cells

Question 2

C cells also called ___ secrets ____

Answer 2

parathyroid cells
calcitonin

Question 3

What are the four steps of thyroid hormone synthesis?

Answer 3

1. iodide uptake
2. activation through oxidation into iodine
3. iodination
4. coupling of iodinated tyrosine

Question 4

which thyroid hormone effects the gene expression?

Answer 4

T3

Question 5

which causes increased calcitonin level?

Answer 5

increased serum calcium level

Question 6

what stimulates the release of T3 and T4

Answer 6

extreme cold
catecholamines
gonadal and adrenocortical increased steroids

Question 7

what decreases the release of T3 and T4

Answer 7

growth hormone inhibiting hormone
dopamine

Question 8

most common causes of primary hyperthyroidism

Answer 8

Grave’s disease
toxic mutinodular goitre
follicular adenomas

Question 9

common causes of secondary hyperthyroidism

Answer 9

pituitary adenomas (TSH-secreting)

Question 10

other causes of thyrotoxicosis

Answer 10

excess thyroid medicaiton
ectopic thyroid tissue
chorionic gonadotropic secreting tumors
gestational thyrotoxicosis (often associated with hyperemesis gravidarum)

Question 11

symptoms of hyperthyroidism are due to

Answer 11

increase metabolic rate
increase CNS stimulation

Question 12

thyroid hormone antagonist to

Answer 12

insulin

Question 13

Grave’s disease is a ______

Answer 13

autoimmune
hypersensitivity type II (cytotoxic)

Question 14

autoantibodies___ bind to the TSH receptors

Answer 14

TSH receptor antibodies or
TSI (thyroid stimulating immunoglobulins)

Question 15

clinical distinguishing factor of Grave’s disease are

Answer 15

Ophthalmopathy: functional and infiltrated (exophthalmos)
Dermopathy: Pretibial myxedema

Question 16

Graves ophthalmopathy is a result of

Answer 16

Production of glycosaminoglycans, which lead to edema and fibrosis

Question 17

nodular thyroid disease diagnosis

Answer 17

Palpable thyroid nodules
Ultrasonography
FNA

Question 18

nodular thyroid disease treatment

Answer 18

medication (Methimazole and propylthiouracil)
radiation
surgery

Question 19

first line treatment for hyperthyroidism

Answer 19

Methimazole (Tapazole)

Question 20

side effects of thionamides

Answer 20

Hepatotoxicity
Hypothyroidism
Rare agranulocytosis is the most dangerous toxicity

Question 21

Methimazole (Tapazole) dosing

Answer 21

Initial:
Mild disease: 5 - 15 mg once daily
Moderate to severe disease: 30 - 40 mg once daily
Severe disease or large goiters: 60 mg once daily
Maintenance: 5-15 mg once Daily

Question 22

Methimazole (Tapazole) contraindication

Answer 22

Crosses placenta; avoid in first trimester
Found in breastmilk, but compatible with breastfeeding at lower doses
Safe for use in infants and children (preferred agent)

Question 23

Propylthiouracil (PTU)

Answer 23

Preferred treatment in pregnancy (compared to methimazole) as crosses the placenta LESS readily

Minimal transfer into breastmilk, but concern for potential neonatal hepatotoxicity → avoid in breastfeeding (methimazole is preferred choice)

Avoid in children if possible due to high risk of hepatotoxicity

Question 24

adjunctive therapy for hyperthyroidism

Answer 24

β-Blockers and nonradioactive iodine may be used as adjunctive therapy

Question 25

thyroid storm symptoms

Answer 25

Profound hyperthermia Restlessness, agitation, tremor, or delirium Severe tachycardia (especially atrial tachycardia) High-output heart failure Nausea, vomiting, diarrhea which contribute to fluid volume depletion

Question 26

thyroid storm treatment

Answer 26

PTU (preferred) or methimazole Beta-blockers for CV symptoms Glucocorticoids Iodine (nonradioactive for acute care) ICU and supportive care

Question 27

Lab Tests for hyperthyroidism

Answer 27

TSH (Biotin can cause false abnormalities) T3 T4 TSH-R-Ab

Question 28

hyperparathyroidism (increased PTH) causes

Answer 28

hypercalcemia and hypophosphatemia

Question 29

3 types of hyperparathyroidism

Answer 29

1. primary: adenomas, hyperplasia, carcinomas 2. secondary: conpensation to chronic hypocalcemia 3. tertiary: autonomous secretion of PTH and hypercalcemia (from severe CKD or kidney transplant)

Question 30

PTH in bones

Answer 30

stimulates osteoblasts to make RANK-L- stimulates osteoclasts to increase bone resorption --> release of calcium and phosphate into the blood

Question 31

PTH in kidney

Answer 31

Calcium reabsorption Phosphate excretion Vitamin D activation

Question 32

Parathyroid hormone increase ___, decrease _____

Answer 32

Parathyroid hormone = ↑ serum calcium, ↓ serum phosphate

Question 33

Primary Hyperparathyroidism symptoms (excessive calcium)

Answer 33

bones stones groans thrones: nephrogenic diabetes insipidus psychiatric overtones

Question 34

Primary & Tertiary: Hyperparathyroidism symptoms

Answer 34

Hypophosphatemia (primary); variable phosphate levels in tertiary Increased active vitamin D (1,25-di-hydroxy-vitamin D3)

Question 35

Secondary hyperparathyroidism symptoms

Answer 35

Hypocalcemia Hyperphosphatemia Decreased active vitamin D (1,25-di-hydroxy-vitamin D3)

Question 36

____ (thyroid condition) is more common in older adults

Answer 36

hyperthyroidism

Question 37

TSH___ in the 1st trimester due to

Answer 37

TSH decrease in 1st trimester due to hCG--> thyroid hormone secretion is stimulated-->. increased serum T4 --> negative feedback reduce TSH secretion

Question 38

Untreated maternal hypothyroidism

Answer 38

associated with ↑ risk of low birth weight and impaired neurocognitive development

Question 39

postpartum thyroiditis

Answer 39

Autoimmune mediated Biphasic presentation: Transient thyrotoxicosis due to release of stored TH from the thyroid gland (↓ TSH, ↑ T4/T3, possible +TPO Ab) Hypothyroid phase (↑ TSH, ↓ T4/T3), followed by return to euthyroid state by end of the first postpartum year

Question 40

congenital hypothyroidism symptoms

Answer 40

hoarse cry, large posterior fontanelle, large tongue, difficulty eating, umbilical hernia, prolonged jaunidice, constipation, lethargy, hypothermia, delayed growth, long-term cognitive disability

Question 41

The period at greatest risk to the newborn for a pregnant person with hypothyroidism is

Answer 41

1st trimester