thyroid function 2

  1. What two hormones play an important role during pregnancy?
    hCG & estrogen
  2. Reasons thyroid function tests during pregnancy could be difficult to interpret?
    hcg & estrogen can cause increased thyroid hormone levels in the blood.
  3. The function of the thyroid gland is to what?
    synthesize thyroxine (T4) and triiodothyronine (T3)
  4. Thyroid cells are the only cells in the body that can absorb this element?
  5. Where is iodine found?
    in many foods
  6. Thyroid cells combine iodine and the amino acid, tyrosine to produce?
    T3 and T4
  7. The T3 and T4 hormones are then released into the bloodstream and are transported thru the body where they play an important role in what?
    controlling metabolism
  8. The thyroid gland is controlled by the __________________ gland.
  9. When levels of T3 and T4 drop too low, what produces the thyrotropin releasing hormone (TRH)?
  10. hypothalamus stimulates the pituitary gland to produce?
  11. TSH in turn stimulates the thyroid gland to produce more?
    thyroid hormones.
  12. Under the influence of ____, the thyroid will manufacture and secrete ________, thereby raising their blood levels.
    TSH; T3 & T4
  13. The hypothalamus senses the rise in T3 and T4 and responds by what?
    decreasing its TRH production Thyroid Hormones
  14. Thyroid hormones are present in the circulation but are mainly bound to what?
  15. Approximately 75% to 80% are bound to ______________ (inactive), and about 20% are bound to _________ (less active).
    thyroxine binding globulin(TBG); albumin
  16. Why is measuring free thyroid hormones generally the most useful in determining thyroid function?
    Because only a small fraction of thyroid hormones is unbound and biologically active,
  17. The TBG protein is generally increased by ___________, and rises especially during _________.
    estrogens; pregnancy
  18. Growing levels of estrogen leads to an increase in ?
    thyroid hormone binding
  19. Less free hormones lead to the stimulation of ________ and further production of _________________.
    TSH ; thyroid hormones
  20. A normally functioning thyroid is able to adapt to changes of TSH and thyroid hormones, and the level of _________________ is not altered.
    Free thyroid hormone
  21. What is Thyroxine?
    hormone referred to as T4 because it contains four iodine atoms.
  22. The normal thyroid gland produces about 80 percent of ____ and is its primary secretory product.
  23. How is T4 converted to T3?
    by the removal of an iodine atom.
  24. What is predominantly bound by proteins?
    T4 and is prevented from entering tissues.
  25. What makes free T4 the most effective way to determine thyroid function?
    ability to enter tissues
Card Set
thyroid function 2
thyroid function #2