Thyroid Hormones #2

Question 1

Thyroid Conditions that don’t develop Goiter?

Answer 1

2. Secondary and Tertiary Hypothyroidism (⬇️TSH and/or ⬇️TRH)

Question 2

Why can iodine deficiency have goiter, but be euthyroid?

Answer 2

1. ⬇️Iodine Deficiency
2. ⬇️T4 and ⬆️T3
3. ⬇️T4 —> ⬇️Negative Feedback —> ⬆️TSH —> ⬆️Hyperplasia and Hypertrophy —> GOITER

Question 3

Most common cause of Hypothyroidism?

Answer 3

Hashimoto’s Thyroiditis

Question 4

Main defect on Hashimoto’s Thyroiditis ?

Answer 4

1. Antibodies vs TPO

Question 5

Main clinical hormonal defects on Primary Hypothyroidism?

Answer 5

1. ⬆️TSH / ⬇️T4

Question 6

Another name for Postnatal Hypothyroidism?

Answer 6

1. Cretinism

Question 7

Main pathological features of Cretinism?

Answer 7

1. Dwarfism
2. Mental Retardation
3. Pot belly
4. Macroglossia

Question 8

Why does Hypothyroidism cause dwarfism or short stature in children?

Answer 8

1. Thyroid hormone is a permissive drug for growth

Question 9

Main radiological sign in Hypothyroidism in children?

Answer 9

1. Stippled Epiphysis (multiple ossification centers)

Question 10

What is the Wolff-Chaikoff effect?

Answer 10

1. ⬆️⬆️amounts of Iodine ⬇️thyroid function

Question 11

Drugs that induce Hypothyroidism through the Wolff-Chaikoff effect?

Answer 11

1. Amiodarone

2. Lithium

Question 12

In what condition is the Wolff-Chaikoff effect more effective ?

Answer 12

1. Graves’ Disease (Primary Hyperthyroidism)

Question 13

Pathophysiology of Graves’ Disease?

Answer 13

1. ⬆️IgG vs TSH receptor un thyroid —> ⬆️T4 production (thyroid stimulating antibodies )

Question 14

Drug that prevents conversion of T4 to T3?

Answer 14

Dexamethasone