Lecture23: Thyroid Gland

Question 1

What 3 hormones does the Thyroid Gland secrete?

Answer 1

T4, T3, Calcitonin

Question 2

What is the main form secreted by the Thyroid Gland?

Answer 2

T4

Question 3

A large amount of T4 is converted to T3 in the peripheral tissues via enzyme…?

Answer 3

Deiodinase

Question 4

Where does the conversion of T4 to T3 take place? 3 places

Answer 4

Gut, liver and kidneys

Question 5

What are the TH effects on metabolic rate?

Answer 5

They increase the metabolic rate and thermogenesis

Question 6

How does TH increase protein synthesis?

Answer 6

Via enhancing the actions of other hormones

Question 7

The conversion of Glucose to glycogen requires how much TH?

Answer 7

Little

Question 8

The breakdown of Glycogen into Glucose requires how much TH?

Answer 8

A lot

Question 9

Does TH increase Fat metabolism?

Answer 9

Yes

Question 10

Up to which point of fetal life does the fetus depend on the thyroxine passinf from the placenta?

Answer 10

11 weeks

Question 11

During which trimester of pregnancy does the Fetal Thyroid become active?

Answer 11

Second Trimester

Question 12

The THs are essential for the nervous system why?

Answer 12

Mylelination, growth of brain during first two years

Question 13

The THs increase which very important receptors the heart?

Answer 13

The Beta-1 adrenergic receptors

Question 14

How does TSH act to regulate the thyroid gland?

Answer 14

It increased cAMP in the thyroxine

Question 15

TH has a direct negative feedback effect on which pituitary?

Answer 15

Anterior

Question 16

What form of TH is responsible for most of the negative feed back?

Answer 16

T4

Question 17

Dietary iodine, when decreased, how does it affect the thyroid function?

Answer 17

Decreases it

Question 18

What is GOITER?

Answer 18

Thyroid enlargement when TSH increases

Question 19

What is the Hyperthyroidism disease called?

Answer 19

Graves Disease

Question 20

What is Hypothyroidism in adults called?

Answer 20

Myxedema

Question 21

What is Hypothyroidism in children called?

Answer 21

Cretinism

Question 22

What is Thyrotoxicosis?

Answer 22

An increase in the circulating thyroid hormones

Question 23

An example of Primary Thyrotoxicosis?

Answer 23

Graves’ disease

Question 24

What is Secondary Thyrotoxicosis?

Answer 24

Pituitary adenoma or pharma caused

Question 25

Explain Graves’ disease?

Answer 25

Antibodies stimulate the TSH receptor, thus no negative feedback mechanism

Question 26

Name manifestations of graves?

Answer 26

Huge gland and increased synthesis rate

Question 27

What are cardiac symptoms of graves?

Answer 27

Tachycardia and a wide pulse pressure

Question 28

Does graves manifest in huge bulging eyes?

Answer 28

Yes

Question 29

What are causes of Cretinism?

Answer 29

No thyroid, or no synthesis of hormones

Question 30

Signs of cretinism?

Answer 30

Short, dull and constipated

Question 31

Manifestations of hypothyroidism?

Answer 31

Decreased BMR, no cold tolerance