Follicular Cells & the Synthesis of Thyroid Hormones

The video explains the synthesis and function of thyroid hormones, focusing on the role of follicular cells in the thyroid gland. It details the process of iodination, formation of T3 and T4 hormones, and their release into the bloodstream. The video also covers the conversion of T4 to the more active T3 form, and the inactivation and elimination of thyroid hormones through deiodination and glucuronidation.

Where is the thyroid gland located in the body?

• In the abdomen

• In the chest

• In the brain

• In the throat

What is the role of thyroid peroxidase in thyroid hormone synthesis?

• It breaks down thyroglobulin

• It activates iodide and attaches it to thyroglobulin

• It transports iodide into the blood

• It converts T4 to T3

What is the significance of the lumen in thyroid hormone synthesis?

• It stores T3 and T4

• It is where iodide is activated and attached to thyroglobulin

• It converts T4 to T3

• It is the site of hormone excretion

What are MIT and DIT in the context of thyroid hormone synthesis?

• Iodinated tyrosine residues

• Enzymes involved in hormone synthesis

• Inactive forms of T3 and T4

• Types of thyroid hormones

What is the common name for Tetra Iodo thyronine?

• Thyroxine

• Thyroglobulin

• Thyroid peroxidase

• Triiodothyronine

What happens to the leftover MIT and DIT that are not fully iodinated?

• They are recycled for future iodination reactions

• They are converted to T3 and T4

• They are excreted as waste

• They are stored in the thyroid gland

What happens to T3 and T4 after they are released into the bloodstream?

• They are immediately excreted

• They travel to tissues to exert their functions

• They are converted into other hormones

• They are stored in the liver

Why is T4 considered a reservoir for T3?

• T4 is more active than T3

• T4 can be converted to T3 in tissues

• T4 is not related to T3

• T4 is stored in the thyroid gland

What is the role of deiodinase enzymes in thyroid hormone regulation?

• They store thyroid hormones in the blood

• They synthesize T3 and T4

• They convert T4 to T3 in tissues

• They activate T4 in the thyroid gland

How are inactive thyroid hormone metabolites eliminated from the body?

• Through the kidneys

• By conversion back to active hormones

• Via glucuronidation and excretion in feces

• By storage in the liver