Flashcards in Thyroid disease Deck (35)
Where is the thyroid gland situated?
In front of the trachea, just below Adam's apple
What are the functional units of the thyroid gland called?
What are thyroid follicles filled with?
Thyroglobulin - acts as a store for iodide
What is iodide needed for?
Production of thyroid hormone
Parafollicular C cells are also found in the thyroid gland. Where are they situated?
What is the role of parafollicular C cells?
Secrete calcitonin - involved in calcium homeostasis
Which enzyme converts T4 into T3?
Where is DIO1 predominantly found?
Liver, kidney, muscles and thyroid gland
Where is DIO2 predominantly found?
CNS and pituitary thyrotropes
Which DIO produces most of the circulating T3?
Which DIO controls intracellular T3 concentration?
Which DIO produces rT3?
How many genes do thyroid hormone receptors have?
2 - THRA and THRB found in the nucleus
Which receptor do thyroid hormone receptors form a heterdimer with?
Retinoid X receptor
What are the 5 biological elements of thyroid hormone?
Control of metabolic rate
What are the symptoms of hypothyroidism?
What are the 3 thyroid function tests that can be performed to diagnose hypothyroidism?
Thyroid peroxidase antibody
In primary hypothyroidism, what happens to unbound T4 and TSH?
Decreased unbound T4
What are carbimazole and propylthiouracil used to treat and how do they work?
Work by interfering with thyroid hormones synthesis by inhibiting thyroid peroxidase activity
What is used to treat hypothyroidism?
Why may B-blockers need to be given TDS/QDS in hyperthyroidism?
Because metabolism is increased
What is B-blockers place in therapy in hyperthyroidism?
Adjuvant therapy - rapid relief of symptoms (tachycardia, tremor etc.)
Which 3 drugs can cause thyroid disease?
Which thyroid disease can iodine deficiency cause?
How can amiodarone cause mild hyperthyroidism?
Blocks conversion of T4 to T3 therefore increases TSH and T4
How can amiodarone cause hypothyroidism?
Inhibition of the synthesis and release of T3 and T4
How does lithium cause hypothyroidism?
Inhibits iodine uptake and prevents T3 and T4 release
Which two hormones regulate calcium homeostasis?
What is the main function of calcitonin?
Reduce blood calcium concentration