L27 Thyroid Flashcards
The thyroid is the largest of the…
True endocrine glands
The thyroid regulates…
Metabolism and body weight
The thyroid has wide ranging effects on a variety of tissues. It is often involved in…
Synergistic effects
The thyroid effects(4)…
- Cardiovascular
- Metabolic
- Neurological
- Growth and development
The thyroid is linked with foetal…
Neural development
The thyroid is linked with bone growth…
After birth
3 products of the thyroid…
- Tetraiodothyronine (thyroxine / T4)
- Triiodothyronine T3
- Calcitonin
Calcitonin regulates…
Calcium homeostasis
T4 thyroxine is the most produced, however T3 thyroxine is…
The most physiologically active
In the thyroid gland, in health, is (palpable / not palpable)…
Not palpable
The thyroid gland has a…
Rich blood supply
On the posterior surface of the thyroid, there are 2 to 4 pairs of a distinct tissue, known as the…
Parathyroid
The functional units of the thyroid are the…
Follicles
The structure of thyroid follicles is a ring of follicular cells interior…
Colloid
The colloid functions to…
Produce and store thyroid hormone
Follicles ( can b cannot ) change size…
Can
Among follicles are distributed C-cells which are…
Bigger and secrete calcitonin
In the colloid tyrosine in thyroglobulin is converted to thyroid hormone precursors by…
Iodination by thyroperoxidase
Thyroid hormone precursors are….
T1 and T2 (mono and diodotyrosine)
In coupling, thyroid hormone precursors…
Are joined together to form T3 and T4 (again by thyroperoxidase)
Iodine moves from the blood into thyroid follicular cells by…
Active transport
Which of the following is true:
a) T3 can be converted to T4
b) T4 can be converted to T3
c) T1 can be converted to T2
d) T2 can be converted to T1
e) All of the above
b) T4 can be converted to T3
Due to its convertibility and longer half life, T4…
Acts as a reservoir for T3
Thyroid hormones require…
Transport proteins
