Thyroid Gland Physiology Lecture 1

Play an AI-generated podcast conversation about this lesson

What is the enzyme responsible for catalyzing the binding of iodine with thyroglobulin?

Thyroid deiodinase
Thyroid hormone receptor
Thyroid peroxidase (correct)
Iodinase

What is the approximate percentage of T4 bound to thyroxin binding globulin (TBG) in the circulation?

40%
70%
80% (correct)
90%

What is the half-life of T4 in the blood?

3 days
1 day
12 days
6 days (correct)

What is the main function of thyroid hormone receptor in the nucleus?

To influence transcription of genes (C) Signup and view all the answers

What is the fate of most of T4 in the targeted tissues?

It is deiodinated to T3 by iodinase enzyme (D) Signup and view all the answers

What is the approximate percentage of free T4 in the circulation?

0.03% (B) Signup and view all the answers

Where is the thyroid gland located?

Below the larynx on either sides and anterior to the trachea (A) Signup and view all the answers

What percentage of thyroid hormones is T4?

90% (D) Signup and view all the answers

What is the function of the iodide pump?

To actively transport iodide into the thyroid gland (D) Signup and view all the answers

What is the result of the coupling of MIT and DIT?

T3 and T4 (A) Signup and view all the answers

What is the name of the enzyme responsible for the oxidation of iodide to iodine?

Thyroid peroxidase (C) Signup and view all the answers

What is the effect of administering a large amount of iodine on thyroid hormone levels?

A decrease in thyroid hormone levels (A) Signup and view all the answers

What percentage of T4 is converted to T3 before binding to the nuclear receptors?

90% (B) Signup and view all the answers

What is the effect of thyroid hormones on carbohydrate metabolism?

Increase glucose uptake by the cells (A) Signup and view all the answers

What is the overall effect of thyroid hormones on protein metabolism?

Catabolic leading to a decrease in muscle mass (C) Signup and view all the answers

What is the effect of thyroid hormones on peripheral resistance?

Decrease peripheral resistance (A) Signup and view all the answers

What is the effect of thyroid hormones on the heart rate?

Increase heart rate (C) Signup and view all the answers

What is the role of thyroid hormones in the prenatal period?

Essential for the maturation of the CNS (C) Signup and view all the answers

What is the effect of a decrease in thyroid hormone secretion on the central nervous system?

Slow movement and impaired memory (D) Signup and view all the answers

What is the role of tripeptide in the regulation of hormone secretion?

Releasing hormone that acts on the thyrotrophs (C) Signup and view all the answers

What is the effect of an increase in thyroid hormone secretion on the respiratory system?

Increased dissociation of oxygen from Hb (A) Signup and view all the answers

What is the role of thyrotropin-releasing hormone (TRH) in the regulation of hormone secretion?

Stimulates the release of TSH from the anterior pituitary (A) Signup and view all the answers

What is the effect of thyroid hormone on bone?

Promotes bone formation (B) Signup and view all the answers

What is the effect of a lack of thyroid hormone secretion on the gastrointestinal system?

Decreased digestive juice secretion (A) Signup and view all the answers