Thyroid

What is the primary cellular composition of the thyroid gland responsible for the synthesis and secretion of thyroid hormones?

Thyroglobulin is synthesized in ____ cells

Adequate ____ intake (diet) is required for normal thyroid hormone production

What effect do thyroid hormones have on the activity of D1, D2, and D3 deiodinases?

What is the primary function of deiodinases in the metabolism of thyroid hormones?

Which clinical condition is associated with D2 deficiency?

What clinical conditions are associated with D3 deficiency?

What is the function of deiodinases in the metabolism of thyroid hormones?

Which type of deiodinase is the most abundant in the body?

Where is Type 3 deiodinase (D3) primarily located?

What is the principle regulator of T3/T4 synthesis and release?

What is the primary feedback mechanism that regulates the synthesis and release of thyroid hormones (T3 and T4) in the thyroid gland?

Increased _____ of almost all tissues occurs with secretion of T3/T4

How do thyroid hormones affect cardiac function?

What is the major hormone produced by the thyroid gland?

How do thyroid hormones influence metabolism?

Which gland produces thyroid-stimulating hormone (TSH)?

How do T3 and T4 impact heart rate?

What is the role of thyroid hormones T3 and T4 in regulating cardiac function?

Thyroid follicles are composed of closed rings of cells (100-300 µm diameter) lined by ____ epithelium filled with colloid

The colloid in thyroid follicles is mostly composed of what?

Which of the following is true in regards to calcitonin?

For follicular cells of the thyroid, the apical surface faces ____ and the basal surfaces faces ____.

93% of total secretion (~80 µg/day) from the thyroid is ____

7% of total secretion (~5 µg/day) is ____

T3 is ____ potent than T4

Which of the following plays an important role in the synthesis and storage of thyroid hormone?

The Sodium/Iodide Symporter (NIS) uses Na+ driving force to move iodine, while ____ is Na+ independent iodide/chloride transporter

In the circulation, what percent of thyroid hormone is found in each of the following states?

With increased levels of estrogen during pregnancy, which of the following occurs, leading to decreased levels of free T3/T4?

Where is Type III deiodinase (D3) primarily found?

What is the role of Type I (D1) and Type II (D2) deiodinases in thyroid hormone metabolism?

How is the activity of deiodinases regulated in the body?

What is the clinical significance of Type III deiodinase (D3)?

What is the primary function of Type I and Type II deiodinases in thyroid hormone metabolism?

How do post-translational modifications like phosphorylation and ubiquitination affect deiodinase activity?

Which clinical condition results from a deficiency of T3 due to reduced deiodinase activity?

What role do deiodinases play in fine-tuning thyroid hormone levels?

In which tissues do deiodinases help concentrate T3 and T4?

What clinical condition can result from mutations impairing the function of deiodinases?

How does TSH affect enzymes involved in T3/T4 synthesis such as TPO?

Where are thyroid receptors located within a cell?

Basal metabolic rate (BMR) can increase _____% above normal when large quantities of T3/T4 are secreted