Thyroid Pcol

Question 1

Thyroid secretes…

Answer 1

Triiodothyronine (T3)
Thyroxine (T4)
Calcitonin

Question 2

Functions of T3 (active thyroid hormone)

Answer 2

Metabolic
Development
Nervous system
Cardiovascular
Reproductive

Question 3

Thyroid Activity

Answer 3

T3 enters target cell and is transported to the cytoplasm where it binds to thyroid receptors
TRs then bind to thyroid response element areas of specific genes

TSH does not work the same-binds to cell membrane receptor

Question 4

Hypothalamic-Pituitary-Thyroid Axis

Answer 4

TRH-thyroid releasing hormone- released when thyroid hormone (T3,T4) is low- released from hypothalamus
TSH-thyroid stimulating hormone from anterior pituitary- travels to thyroid (where the TSH receptors are)
T3- active- binds to thyroid receptor (changes gene transcription)
T4-inactive- body secretes a lot of T4 (pool to recruit from when we need more T3) needs to be converted to T3

Question 5

C-cells make…

Answer 5

Calcitonin- responsible for making T3 and T4

Question 6

Thyroid follicular cell functions

Answer 6

uptake of iodine
formation of thyroglobulin
formation and secretion of T3 and T4

Question 7

Uptake of Iodine-Iodine transport

Answer 7

Na/I symporter
TSH stimulates production and insertion of the symporter into the membrane
very high iodine levels in the blood will shut down these transporters

Question 8

Follicular cells produce

Answer 8

T3 and T4

made in cell and sent out

Question 9

TSH stimulates

Answer 9

activity of transporter
increase in thyroglobulin
increases Na/I
TSH receptor is cell membrane
thyroid has a cytoplasmic receptor
thyroglobulin- backbone on which thyroid hormone is built on

Question 10

Iodide/Na Symporter

Answer 10

a