thyroid

Question 1

what two main classes of hormones does the thyroid release?

Answer 1

T3 and T4 thyroid hormones

calcitonin

Question 2

what kind of feedback do T3 and T4 hormones induce upon the hypothalamus and pituitary

Answer 2

negative

Question 3

what is TRH? where is it released from?

Answer 3

thryotropin releasing hormone, hypothalamus

Question 4

what is TSH? where is it released from?

Answer 4

thyroid stimulating hormone, anterior pituitary

Question 5

how do thyroid hormones affect the basal metabolic rate

Answer 5

increase

Question 6

what are thyroid hormones effect with relation to catecholamines?

Answer 6

makes body more sensitive to catecholamines

Question 7

how does catecholamine sensitivity affect cardiac output ?

Answer 7

increase

Question 8

what are the three powerful physiological effects of thyroid hormones?

Answer 8

1. increased basal metabolic rate
2. sensitivity to catecholamines
3. important roles in growth and development

Question 9

where in the follicle does iodination and coupling of thyroglobulin occur?

Answer 9

apical side/ follicle lumen

Question 10

where in the follicle does processing of thryoglobulin occur ?

Answer 10

intracellular

Question 11

where are T3 and T4 released from in the follicle?

Answer 11

basolateral side (bloodstream)

Question 12

how does iodide get into the follicular cell from the bloodstream?

Answer 12

Na/I cotransporter

Question 13

what kind of receptor is the thyroid hormone receptor?

Answer 13

intracellular

Question 14

How are T3 and T4 taken up into the cell?

why must they be taken up like this?

Answer 14

need to be taken up by transporter proteins because they are not very lipid soluble

Question 15

at rest, where can unbound thyroid hormones associate with?

what do they recruit?

Answer 15

response elements (TRE), recruit co-repressors

Question 16

what is the action of co-repressors?

Answer 16

weaken gene transcription

Question 17

how does t4 become t3

Answer 17

de-iodination

Question 18

T3 binding in the nucleus causes recruitment of _______ to form a _______ with the thyroid hormone receptor.

Answer 18

RXR retinoic acid receptor, heterodimer

Question 19

thyroid recruitment of what can lead to enhanced transcription of target genes?

Answer 19

co-activators

Question 20

define hypothyroidism

Answer 20

underactive thyroid/ not enough thyroid hormones

Question 21

what are the major causes of hypothyroidism? (list 4)

Answer 21

iodine deficiency
autoimmunity towards thyroid
congenital defect
inappropriate hormonal regulation

Question 22

hypersensitivity to cold is a symptom of _____? (hyper or hypo thyroidism)

Answer 22

hypo

Question 23

weight gain is a symptom of _______. (hypo or hyperthyroidism)

Answer 23

hypo

Question 24

bradycardia is a symptom of ________. (hypo or hyperthyroidism)

Answer 24

hypo

Question 25

what are the two types of hypothyroidism? measurement of _______ can help distinguish which one is afflicting a patient.

Answer 25

1. primary hypothyroidism 2. secondary hypothyroidism TSH (thyroid-stimulating hormone)

Question 26

what causes primary hypothyroidism?

Answer 26

DEFECT in thyroid function

Question 27

what causes secondary hypothyroidism?

Answer 27

central defect ie poor function of anterior pituitary or hypothalamus

Question 28

what are the features (ie hormone amounts) in someone with primary hypothyroidism?

Answer 28

low T3/ T4 | high TSH

Question 29

what are the features (ie hormone amounts) in someone with secondary hypothyroidism?

Answer 29

low T3/T4, low TSH

Question 30

what is the most common treatment of hypothyroidism

Answer 30

hormone replacement with synthetic thyroxine (T4)

Question 31

WHAT IS LEVOTHYROXINE? | what does it treat?

Answer 31

synthetic T4 hormone | treats hypothyroidism

Question 32

what are the 2 common causes of hyperthyroidism?

Answer 32

Grave's disease | hyperplasia of the thyroid

Question 33

what causes Grave's disease?

Answer 33

stimulatory auto-antibodies that activate the TSH receptor

Question 34

what is hyperplasia?

Answer 34

enlargement of an organ

Question 35

what are thyroid adenoma and goitre?

Answer 35

enlargementh of the thyroid gland causing hyperthyroidism

Question 36

heat intolerance is a symptom of _______ (hyper or hypo thyroidism)

Answer 36

hyper

Question 37

tachycardia is a symtpom of _________ (hyper or hypo thyroidism)

Answer 37

hyper

Question 38

tremor is a symptom of (hyper or hypothyroidism)

Answer 38

hyperthyroidism

Question 39

what is secondary hyperthyroidism ?

Answer 39

central defect in the anterior pituitary, too much TSH release

Question 40

what are the features (ie hormonal amounts) present in Grave's disease?

Answer 40

low TSH high T3, high T4 detection of anti-TSH receptor antibodies

Question 41

what feature (ie hormonal amounts) is present in thyroid hyperplasia

Answer 41

high T3 and T4 | low TSH

Question 42

what features (ie hormonal amounts) are found in someone with secondary hyperthyroidism?

Answer 42

high TSH | high T3 and T4

Question 43

what physiological signifier might suggest that someone has high levels of anti-TSH

Answer 43

bulging eyes or exophthalmos

Question 44

what does Hashimoto's thyroiditis cause? | hypo or hyper thyroidism

Answer 44

hypo

Question 45

what is goitre? | what two things may cause goiter?

Answer 45

swelling of the neck 1. overactivation of thyroid tissue 2. iodine deficiency / increased TSH levels

Question 46

what does methimazole do? to what class of drug does it belong? what is it used to treat? what are the drawbacks?

Answer 46

prevents steps of T4/T3 synthesis thioamides hyperthyroidism diverse side effects

Question 47

what is radioactive iodine treatment what does it treat what are its drawbacks?

Answer 47

destruction of the thyroid hyperthyroidism should not be used in pregnant women because infant can have permanent thyroid damage

Question 48

how can surgery cure hyperthyroidism? what are the drawbacks?

Answer 48

resection of part of all of the thyroid + hormone replacement potential to disrupt parathyroid gland, may cause hypothyroidism

Question 49

how does treatment with beta-blockers help those with hyperthyroidism?

Answer 49

may help with the tachycardia caused by hyperthyroidism

Question 50

what is a thioamide? what can it be used to treat

Answer 50

Prevents iodination and coupling steps, used to treat hyperthyroidism