Hyperthyroidism Flashcards
Why is hyperthyroidism hard to detect in children?
They have a high BMR anyway
Very rare
Signs/symptoms of hyperthyroidism
Heat intolerance Sweaty Increased BMR Weight loss Tachycardia GI hyper mobility Osteoporosis Exopthalmus
Why may osteoporosis occur?
Increased bone turnover
Most common cause of hyperthyroidism?
Graves’ disease
Plasma Levels seen with hyperthyroidism (with thyroid fault)
Increased T3
Increased T4
very low TSH
What causes Grave’s disease?
Autoimmune
Antibodies (TSI) produced
Stimulate TSH receptors on follicle cells
What causes a rise in T3 and T4 and very low TSH?
Lots of T3 and T4
Negative feedback loop
Less TSH released
(Still high T3/T4 because TSI is still stimulating the production, not the TSH)
Treatment for hyperthyroidism
- Carbimazole
* Surgery
How does Carbimazole work?
Inhibits Thyroid Peroxidase enzyme
What does Thryoid Peroxidase do?
Where is it?
Incorporates iodine into Thyroglobulin to form T3/T4
Membrane bound
Effect of hyperthyroidism in childhood development…
Mature earlier BUT NOT MORE!!
What is the name of the antibody produced in Graves’ disease?
TSI- thyroid stimulating immunoglobulin
Other effects of high T3/T4?
Nervous system is especially sensitive–> increased myelination, speed of relflexes, mental activity. Increased cardiac output, and protein turnover in skin
What are the effects of carbimazole?
Inhibits thyroid Peroxidase, TF less activation of iodide ions, TF less T3/T4 made
Where is T3/T4 made and stored?
Made in follicular thyroid cells, stored in colloid lumen in thyroid.
