233.A 45-year-old woman, who works as a corporate executive, presents
with the primary complaint of “always being tired.” She comments that she
has been tired for 4 months even though she is sleeping more. She com-
plains of being unable to finish household chores and “dragging at work.”
She indicates that she is often constipated and is intolerant to cold. She is
continuously turning the thermostats in the house and work to higher tem-
peratures, to the dismay of family members and coworkers, respectively. She
also complains that her skin is very dry; use of lotions and creams have
not helped the dryness. A biopsy of the organ shown in question 227 indi-
catesdense lymphocytic infiltration with germinal centers throughout the
parenchyma. A battery of tests is carried out. You would expect which of
the following?
a. Elevated TSH levels in the serum
b. Elevated T3 and T4 levels in the serum
c. Autoantibodies to the thyroid hormone receptor
d. Elevated calcitonin levels
e. Elevated glucocorticoid levels
234.Measuring T3 levels does not necessarily accurately depict the thy-
roid’s ability to secrete T3 for which of the following reasons?
a. T3 is bound to thyroid-hormone binding proteins
b. The liver and kidney convert T4 to T3 peripherally
c. T3 and T4 are regulated by two different anterior pituitary hormones
d. Thyrotrophs produce T3
e. T4 and T3 immunoassays cross-react in immunoassays
Endocrine Glands 349