Thyroid Physiology Flashcards Preview

2MB Endocrinology > Thyroid Physiology > Flashcards

Flashcards in Thyroid Physiology Deck (13)
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1
Q

List the main thyroid hormones

A

Thyroxine (T4)
Triiodothyronine (T3)
Calcitonin

2
Q

What chemical is the main “fuel source” of the thyroid?

A

Iodine

3
Q

What happens to iodine once it is taken up by the follicle cells of the thyroid?

A

Combines with tyrosine residues on thyroglobulin to form MIT or DIT

4
Q

Outline the composition of T3

A

MIT + DIT

5
Q

Outline the composition of T4

A

DIT + DIT

6
Q

T3 is the more abundant thyroid hormone. True/False?

A

False

T4 makes up 90% of thyroid hormones

7
Q

Is T3 or T4 more biologically active?

A

T3

8
Q

T4 is converted to T3 by liver/kidney. True/False?

A

True

9
Q

The unbound form of thyroid hormone is biologically inactive. True/False?

A

False

Unbound is active!

10
Q

What are the 2 main types of cell found in the thyroid?

A

Follicular cells

Parafollicular C cells

11
Q

What is stored in the colloid of the thyroid?

A

Thyroglobulin

12
Q

What do follicular cells secrete?

A

Thyroglobulin

13
Q

T3 and T4 are hydrophobic. True/False?

A

True