Laboratory Investigation of Endocrine Disorders Flashcards Preview

π’žπ“π’Ύπ“ƒπ’Ύπ’Έπ’Άπ“ π“‘π’Ύπ‘œπ’Έπ’½π‘’π“‚π’Ύπ“ˆπ“‰π“‡π“Ž > Laboratory Investigation of Endocrine Disorders > Flashcards

Flashcards in Laboratory Investigation of Endocrine Disorders Deck (68)
Loading flashcards...
1

What is synthesis and release of TH controlled by?

➝ TSH

2

What is the main hormone secreted by the thyroid?

➝ T4

3

What is the biologically active form of the hormone secreted from the thyroid and how does this occur?

➝ T3
➝ peripheral conversion from T4

4

Describe the thyroid hormone axis?

➝ Hypothalamus produces TRH
➝ TRH acts on the pituitary gland which produces TSH
➝ TSH acts on the thyroid
➝ thyroid produces T3 and T4
➝ T4 and T3 act on tissues and feedback negatively to the pituitary
➝ in peripheral tissues T4 is converted to T3 which feedsback negatively to the hypothalamus

5

What are thyroid hormones needed for?

➝ Normal growth and development

6

What is the effect of thyroid hormone?

➝ increases basal metabolic rate (BMR) and affect many metabolic processes

7

What are T3 and T4's effects mediated by?

➝ activation of nuclear receptor

8

What is the normal total and free T4 concentration?

➝ total : 60-150 nmol/L
➝ free : 11-23 pmol/L

9

What is the normal total and free T3 concentration?

➝ total : 1-2.9 nmol/L
➝ free : 4-8 pmol/L

10

What is the half life of T4 compared to T3?

➝ T4 6-7 days
➝ T3 0.5-1 day

11

What is euthyroid?

➝ normal range

12

What is hypothyroid?

➝ below

13

What is hyperthyroid?

➝ above

14

What is primary hyper/hypo thyroidism?

➝ dysfunction is in the thyroid gland

15

What is secondary hyper/hypo thyroidism?

➝ dysfunction is in the pituitary

16

What is tertiary hyper/hypo thyroidism?

➝ hypothalamus dysfunction

17

What is hyperthyroidism?

➝ excessive production of thyroid hormones

18

What are the clinical features of hyperthyroidism?

➝ weight loss
➝ heat intolerance
➝ palpitations
➝ goitre
➝ eye changes

19

What happens in extreme hyperthyroidism?

➝ thyroid storm

20

What are the 4 causes of hyperthyroidism?

➝ Graves disease (most common)
➝ toxic multinodular goiter
➝ toxic adenoma
➝ secondary : excess TSH production

21

What is Graves disease due to?

➝ Due to stimulatory TSH-R antibodies which activate the receptor in the absence of TSH

22

What is hypothyroidism?

➝ Deficient production of thyroid hormones

23

What are the clinical features of hypothyroidism?

➝ weight gain
➝ cold intolerance
➝ lack of energy
➝ goitre
➝ congenital - developmental abnormalities

24

What are the biochemistry results for an investigation on hypothyroidism?

➝ Raised TSH
➝ reduced T4

25

What does reduction in TSH and T4 suggest?

➝ hypopituitarism

26

What are the 5 causes of hypothyroidism?

➝ Autoimmune thyroiditis (Hashimotos)
➝ thyroid peroxidase antibodies (anti-TBO)
➝ iodine deficiency
➝ Toxic adenoma
➝ secondary - lack of TSH

27

if TSH levels are high what does this indicate?

➝ lack of thyroid effectiveness

28

if TSH is very low and T4 and T3 are very high what does this mean?

➝ the disorder is primary

29

What does functional zonation of the cortex mean?

➝ different hormones made in each layer

30

Where does blood flow in the adrenal cortex?

➝ from outer cortex to inner medulla