Thyroid Hormone

Question 1

What are the two main thyroid hormones?

Answer 1

T3 (Triiodothyronine) and T4 (Thyroxine).

Question 2

Which thyroid hormone is more active?

Answer 2

T3 is more active than T4.

Question 3

Which thyroid hormone is produced in larger amounts?

Answer 3

T4 is made more than T3, but T4 is converted into T3 in the body.

Question 4

What is reverse T3 (rT3)?

Answer 4

An inactive form of T3 that doesn’t have an effect on the body

Question 5

What other hormone is made by the thyroid gland?

Answer 5

Calcitonin, which helps lower calcium levels in the blood

Question 6

What mineral is needed to make thyroid hormones?

Answer 6

Iodine

Question 7

What enzyme helps in thyroid hormone production?

Answer 7

Thyroid peroxidase (TPO)

Question 8

What happens if iodine is too high?

Answer 8

Too much iodine can block thyroid hormone production (Wolff-Chaikoff effect).

Question 9

What protein stores thyroid hormones inside the thyroid?

Answer 9

Thyroglobulin (Tg)

Question 10

How are thyroid hormones carried in the blood?

Answer 10

They bind to a protein called Thyroid-Binding Globulin (TBG)

Question 11

What happens if TBG levels increase (e.g., in pregnancy)?

Answer 11

More thyroid hormones are bound, but free T3/T4 remain normal

Question 12

Where do thyroid hormones act in the body?

Answer 12

They bind to nuclear receptors to control gene expression

Question 13

Do thyroid hormones act fast or slow?

Answer 13

They act slowly because they control gene activity

Question 14

How do thyroid hormones affect metabolism?

Answer 14

They increase metabolism, heat production, and oxygen use

Question 15

How do thyroid hormones affect the heart?

Answer 15

They increase heart rate and blood pressure by increasing B1 receptors.

Question 16

Why are thyroid hormones important for babies?

Answer 16

They help with brain development and bone growth

Question 17

What happens if a baby lacks thyroid hormones?

Answer 17

They can have mental delays and short stature (Cretinism)

Question 18

What two hormones control thyroid hormone levels?

Answer 18

TRH (from the hypothalamus) and TSH (from the pituitary gland)

Question 19

What happens if thyroid hormone levels are too high?

Answer 19

TSH goes down (negative feedback)

Question 20

What disease causes too much thyroid hormone?

Answer 20

Graves’ disease (hyperthyroidism)

Question 21

What disease causes too little thyroid hormone?

Answer 21

Hashimoto’s thyroiditis (hypothyroidism).

Question 22

What are symptoms of hyperthyroidism (too much thyroid hormone)?

Answer 22

Fast heart rate, weight loss, sweating, tremors, nervousness

Question 23

What is exophthalmos?

Answer 23

Bulging eyes in Graves’ disease

Question 24

What are symptoms of hypothyroidism (too little thyroid hormone)?

Answer 24

Slow metabolism, weight gain, cold intolerance, dry skin, fatigue

Question 25

What is myxedema?

Answer 25

Severe hypothyroidism causing swelling, slow speech, and tiredness

Question 26

What is endemic goiter?

Answer 26

Thyroid swelling due to iodine deficiency

Question 27

What is cretinism?

Answer 27

Severe hypothyroidism in babies, causing mental and physical delays

Question 28

What is the most active thyroid hormone?

Answer 28

T3 (Triiodothyronine)

Question 29

What protein carries thyroid hormones in the blood?

Answer 29

Thyroid-binding globulin (TBG)

Question 30

What mineral is needed to make thyroid hormones?

Answer 30

Iodine

Question 31

What enzyme helps add iodine to thyroid hormones?

Answer 31

Thyroid peroxidase (TPO)

Question 32

What disease causes too much thyroid hormone?

Answer 32

Graves’s disease

Question 33

What disease is caused by the immune system attacking the thyroid?

Answer 33

Hashimoto’s thyroiditis

Question 34

What is the effect of too much iodine on the thyroid?

Answer 34

It blocks thyroid hormone production (Wolff-Chaikoff effect)

Question 35

How do thyroid hormones affect heart rate?

Answer 35

They increase heart rate by increasing B1 receptors

Question 36

What happens to TSH levels in Graves’ disease?

Answer 36

TSH goes down due to too much thyroid hormone

Question 37

What hormone stimulates the thyroid gland?

Answer 37

TSH (Thyroid-Stimulating Hormone).

Question 38

What hormone is released from the hypothalamus to control the thyroid?

Answer 38

TRH (Thyrotropin-Releasing Hormone)

Question 39

What is a symptom of hyperthyroidism related to the eyes?

Answer 39

Exophthalmos (bulging eyes)

Question 40

What happens if a newborn has too little thyroid hormone?

Answer 40

Cretinism (mental and growth delays)