Lec 7 - Thyroid disorders

Question 1

iodine deficiency effect

Answer 1

= derbyshire neck
non-toxic GOITRE
- effect of thyroid gland trying to extract iodine from blood
- lack of iodide means less T3 produced = NO NEGATIVE FEEDBACK to stop TSH

Question 2

potential causes hypothyroidism

Answer 2

• inadequate iodide in diet
• impaired TSH receptor function
• goitrogens
• impaired conversion of T4 to T3
• iatrogenic
• autoimmune destrution of thyroid gland

Question 3

examples of goitrogens and why is bad

Answer 3

foods
- cassava
- cherries
- almonds
= all rich in thiocynate
inhibit TPO enzyme
AND competitively inhibits NIS

Question 4

features of hypothyroidism

Answer 4

(slow metabolism)
- overweight
- lethargy
- dry, cool skin
- myxedemia
- hair loss
- fatigue
(easily confused with menopause)

Question 5

3 ways of treatment of hypothyroidism

Answer 5

• restore iodide supply
  -thyroxine tablets
• triiodothyronine tablets

Question 6

potential causes of hyperthyroidism

Answer 6

• hyperstimulated thryoid gland (e.g. TSH secreting tumour in pituitary)
• autonomously functioning thyroid
• autoimmune stimulation of thyroid by TSH receptor antibodies (Graves Disease = most common)

Question 7

graves disease cause

Answer 7

thyroid stimulating immunoglobulin (TIS) that stimulates thyroid gland

Question 8

2 distinct symptoms of graves disease

Answer 8

clearly visibile goitre
but mainly
- Thyroid-associated ophthalmopathy

Question 9

thyroid associated ophtalmopathy cause

Answer 9

• due to antibodies attacking fatty tissue behind eye = inflammation
• epitope sharing between thyroid glant and orbit

Question 10

general symptoms of hyperthyroid

Answer 10

• weight loss
• goitre - sometimes
• large appetite
• warm, sweaty
• nervousness, tremor
• cardiac abnormalities
• osteoporosis

Question 11

treatment of hyperthyroidism

Answer 11

• surgical removal of thyroid gland
• radioactive iodine treatment

Question 12

hyperthyroidism drug treatment

Answer 12

• thionamide drugs:
  > have THIOCYANATE group (remember this inhibits TPO and decreases iodine uptake)
  and therefore reduces T4 and T3 output

Question 13

problems of thionamide drugs

Answer 13

• slow response
• relapse common
• if long term = goitre= because not much feedback on TSH
• skin rashes
• agranulocytosis (dangerous for infection
• liver damage (hepatic enzyme induction)