00:01
Okay, this question involves the production of thyroid hormones from epithalamus to the thyroid gland and also the definition of negative feedback loop.
00:16
So first let's see how thyroid hormones are produced.
00:21
First, here is your hypothalamus.
00:26
It is in the brain.
00:28
Then you have here the hypothesis or pituitary gland and finally you have here the thyroid gland okay now first the goal of this system is to produce thyroid hormones that are t3 and t4 okay in order to achieve this the hypothalamus first needs to produce a hormone called trh.
01:08
Okay, this trh is going to be produced by the hypothalamus and it is going to be sent to the blood and it is going to stimulate the pituitary gland to produce another hormone called thsh.
01:21
Okay.
01:22
Finally, thsh is going to travel through the blood and get to the thyroid gland where it is going to stimulate it and produce t3 and t4 that are thyroid hormones.
01:35
Now let's see what is the definition of a negative feedback loop.
01:42
This is a system.
01:44
This is our system.
01:46
So this is a negative feedback loop occurs when the reaction of this system causes a response...