4 Thyroid

Question 1

what is T4?

Answer 1

thyroxine

Question 2

what is T3?

Answer 2

triiodothyronine

Question 3

what do T4 and T3 do?

Answer 3

stimulates metabolism of all cells

Question 4

what does calcitonin do?

Answer 4

decreased blood calcium concentration by inhibiting breakdown of bone

Question 5

how is T3 and T4 released?

Answer 5

TRH by hypothalamus which act on thyrotrophs in anterior which then produce TSH which then stimulates thyroid gland to produce T4 and T3

Question 6

what are the features of the TSH receptor?

Answer 6

it is a GPCR that activates a cAMP pathway to increase production of the T3/T4

Question 7

how is TSH production regulated?

Answer 7

via negative feedback at TRH neurones in hypothalamus and at thyrotrophs

Question 8

what are the signs of a thyroid disorder?

Answer 8

moon face, weight gain, fat accumulation of upper back, mood swings, impaired memory

Question 9

what is the mechanism of a thyroid function test?

Answer 9

the higher the TSH the lower the thyroid function as less T3 or T4 being produced

Question 10

what type of hypothyroidism is most common?

Answer 10

autoimmune

Question 11

what is Hashimoto’s?

Answer 11

autoimmune hypothyroidism

Question 12

what type of treatment may result in hypothyroidism?

Answer 12

end stage radioactive graves treatment

Question 13

what are the indicators of hypothyroidism?

Answer 13

iodine deficiency, decreased thyroid hormones, slower metabolism, susceptible to cold as less heat generated

Question 14

what are the symptoms of hypothyroidism?

Answer 14

weakness, fatigue, cold intolerance, decreased sweating, weight gain, impaired glucose tolerance

Question 15

what is primary hypothyroidism?

Answer 15

issue with the thyroid

Question 16

what is secondary hypothyroidism?

Answer 16

issue with the pituitary gland causing decreased stimulation of thyroid

Question 17

what is tertiary hypothyroidism?

Answer 17

hypothalamus no longer functioning preventing the flow of hormones

Question 18

what kind of hypothyroidism does a high TSH indicate?

Answer 18

primary as indicates that the thyroid is not working to produce hormones for negative feedback

Question 19

what is the treatment of hypothyroidism?

Answer 19

synthetic thyroxine to replace T4

Question 20

what makes type I diabetics more likely to suffer with hypothyroidism?

Answer 20

autoimmunity may damage the thyroid

Question 21

what is Grave’s disease?

Answer 21

hyperthyroidism

Question 22

what could hyperthyroidism be caused by?

Answer 22

toxic multi nodular goiter, TSH secreting pituitary tumour, molar pregnancy

Question 23

what are the common symptoms of graves disease?

Answer 23

hyperactivity, insomnia, excessive sweating, weight loss, increased defecation

Question 24

what are the less common symptoms of hyperthyroidism?

Answer 24

loose nails, impotence, nausea or vomiting

Question 25

what is a goiter?

Answer 25

swollen thyroid gland

Question 26

what does an assessment of the goiter include?

Answer 26

size, painfulness, smoothness, is it causing issues to breathing

Question 27

what things indicate diagnosis of hyperthyroidism?

Answer 27

TSH suppressed due to high T4, toxic multi nodular goiter, check T3 in case of thyrotoxicosis, check response to TSH

Question 28

what is the treatment of hyperthyroidism? how does it work?

Answer 28

radioactive iodine as this is transported to the thyroid and so will kill the tissue that is producing too much hormone

Question 29

what patients cannot have radioactive iodine treatment?

Answer 29

children or pregnant women

Question 30

what are the issues with radioactive iodine?

Answer 30

increases chances of hypothyroidism as cannot now produce enough hormone

Question 31

what drugs can be used to treat hyperthyroidism?

Answer 31

propylthiouracil and propranolol

Question 32

what does propylthiouracil do?

Answer 32

blocks thyroid hormone synthesis

Question 33

what does propranolol do?

Answer 33

blocks hormone effects by inhibiting conversion of T3 to T4

Question 34

how is thyroiditis caused?

Answer 34

by viral infections

Question 35

what are the symptoms of thyroiditis?

Answer 35

tender thyroid with fever and malaise

Question 36

how can thyroiditis be treated?

Answer 36

using beta blockers such as propranolol

Question 37

what is Hashimoto's thyroiditis?

Answer 37

inflammation of the thyroid causing hypothyroidism