Thyroid Drugs Flashcards
Explain the effects of the thyroid gland.
- Thyroid hormones are essential for normal growth, development and metabolism.
- Production is tightly regulated through the Hypothalamus-Pituitary-Thyroid axis.
- Thyroid gland is the only gland capable of incorporating iodine into organic molecules
- Thyroid disease is VERY common, particularly in women, and the prevalence rises with age.
- Once diagnosed, many thyroid diseases can be treated, with an excellent long-term outcome for most patients.
What plays an important factor in thyroid function?
Dietary iodide.
What type of cells secrete thyroid hormones?
Follicular cells
Give examples of thyroid hormones.
- Thyroxin (T4)
- Tri-iodothyronine (T3)
Explain the biosynthesis of thyroid hormones.
- Trapping of iodide
- Synthesis of thyroglobulin (TG)
- Oxidation of iodide (TPO)
- Organification of iodine at tyrosine
site (TPO) - Coupling - T1>T2>T3>T4 (TPO)
- Pinocytosis of colloid
- Secretion of thyroid hormones
- Transport of thyroid hormones into
blood
(TPO: Thyroid Peroxidase)
Explain the structure-activity relationship of thyroid hormones.
- Derived from the amino acid tyrosine
– Two phenyl rings coupled through an X group.
– The phenyl rings must be appropriately substituted for hormone action.
What types of substituents are needed to maximise thyroid activity?
Explain the T4 decoupling process to make active T3.
Explain the actions of thyroid hormones.
Draw and label the diagram that represents the action of thyroid hormones.
What function does TSH levels test for?
What would be the TSH levels for a healthy individual?
What would be the TSH levels for a patient with hypothyroidism?
What would be the TSH levels for a patient with hyperthyroidism?
Explain the process of thyroid scanning.
