Thyroid

Question 1

Explain the products of the coupling of iodinated tyrosine residues

Answer 1

MIT (monoiodotyrosine) - one iodine per tyrosine

DIT (diiodotyrosine) - two iodine per tyrosine

Question 2

Describe the coupling of DIT and MIT

Answer 2

DIT + DIT = T4 (thyroxine)

DIT + MIT = T3 (triiodothyronine)

Question 3

Explain the role of TBG

Answer 3

Thyroxine bingding globulin binds T3 and T4 to enable transport in the blood as they have poor solubility in water

Question 4

Name THREE diseases associated with thyroid dysfunction

Answer 4

Goitre
Hypothyroidism
Hyperthyroidism

Question 5

What causes Goitre?

Answer 5

Hypertrophy of the thyroid gland (excess stimulation of TSH)

Question 6

What are the symptoms of hypothyroidism? (5)

Answer 6

Weight gain
Cold intolerance
Lethargy
Depression
Puffiness of skin

Question 7

What is the treatment for hypothyroidism?

Answer 7

Lifelong replacement of T4 - levothyroxine

Question 8

What are the symptoms of hyperthyroidism? (3)

Answer 8

Weight loss
Heat intolerance
Eyeball protrusion

Question 9

What treatment should be given for hyperthyroidism?

Answer 9

Carbimazole