Endocrinology | Thyroid Overview

our engineer so we talked about the thyroid gland in super great detail we covered things in so much detail that what I wanted to do in this video was just give us a nice little overview of that entire video so let's go ahead and dive right in so if you look here we're going to start the hypothalamus so if you remember in the hypothalamus there were specific neurons right that we're actually releasing the specific chemical and what was that chemical that they were seek reading that chemical was called thyrotropin-releasing hormone and if you want the nucleus was called the paraventricular nucleus right what would that tre is doing it was flowing through the hypophyseal portal system which was just a vascular connection right here right here's a little vascular connection it was flowing through that we're down into the anterior pituitary and in the anterior pituitary there was some specific cells right there what were these cells here called these were called thyrotropin right and these thyroid ropes were responding to the trh and what were they see creating they were see creating what's called thyroid stimulating hormone right so the first step was trh second step was TSH what's the next thing well now we have the thyroid gland what has to happen if the thyroid stimulating hormone is going to circulate down through the blood to the thyroid gland and then it's going to act on the thyroid gland when it acts on the thyroid gland if you remember we said that the overall results of this was the production of t3 and t4 which stands for our thyroid hormone right and then we said that it's transported in the blood stream through the thyroxine binding globulin s'right and exerts its effects on various different target organs which we're going to talk about number reef second here what I want to do is so now that we understand this was called hypothalamic pituitary thyroid axis let's say something real quick about what happens whenever you have too much or too low how does this affect it so if you think about it for a second let's say that your T H levels are high your thyroid hormone levels are high what does that do so let's do all here in red it can actually circulate back up to the hypothalamus and exert what's called a negative feedback mechanism what does that mean it inhibits the paraventricular nucleus from you're making trh if you don't make a lot of trh what do you not make a lot of TSH if the th let TSH levels drop do you make as much t3 and t4 no okay so high t3 and t4 negative feedback low T RH low TSH and then as a result low t3 and t4 what about the opposite if you have low t3 and t4 what is it going to do it's going to exert a negative feedback mechanism on the paraventricular nucleus cause excessive amounts of trh produce excessive amounts of TSH and then the high amounts of TSH will stimulate the increase in t3 and t4 so simple as that alright now that we've done that let's look at the effects of t3 and t4 on these various target organs and like I said we've already gone into all of them in great detail so we're just going to get the overall look what was its effects on bone it just promotes normal bone growth so promotes normal bone growth and maturing so it helps with being able to promote normal bone growth and maturation guess what else it does it promotes normal muscular system development and function so it promotes normal muscular function and development okay what about on just normal body cells do you remember it increase the basal metabolic rate by increasing the sodium potassium ATPase oh so it increases your basal metabolic rate it increases the oxygen usage and then it actually can cause more metabolism right what are some of those metabolic pathways that it does so it can actually do what's called lipolysis it can actually do what's called glycolysis and it can even do another process which is called gluco neo Genesis so it's actually a hyperglycemic hormone right because it has the ability to increase blood glucose levels via gluconeogenesis and it can break down substance because your basal metabolic rate is increasing you want to break down lot of glucose there's a lot of glycolysis and helps to break down fat oh one more that I want to mention here which is really really important it it helps with what's called LDL uptake so LDL is the cholesterol is called lipo density low-density lipoprotein and it actually is bad cholesterol so if we what it helps to do is get a lot of that bad cholesterol out of the blood and into our liver cells right so it helps to increase the LDL uptake which helps to lower the actual cholesterol is within the plasma okay so that's its effects there what does it do on the heart it promotes normal cardiac output so it promotes normal cardiac output right so cardiac output and different types of other functions right all right what about on the brain it promotes normal nerve development so it promotes the actual increase in the synapses so what does it do it increases the synapses it increases the myelination it increases the dendrites so all of these things are helping to do what increase the actual nervous system development of function so it helps to be able to promote these activities what does it do on the GI tract it promotes normal GI motility and function so it promotes motility so contractions so it promotes motility and secretions of the GI tract and then again what does it do to the skin it promotes the normal hydration of the skin so it promotes normal hydration of the skin okay so if we understand this this is the basic overall function of thyroid hormone so what happens trh is regulating the production of TSH by the anterior pituitary TSH is acting on our thyroid gland to produce thyroid hormone and thyroid hormone can produce bone growth maturation normal muscular function and development increase our basal metabolic rate and oxygen usage and it can undergo lipolysis mechanisms glycolysis mechanisms gluconeogenic mechanisms and it can increase the uptake of LDLs low density lipoprotein for most normal cardiac output and pumping functions increasing the synapses and the myelination and the dendrites within our central nervous system and it helps to promote normal motility and secretions of the gastrointestinal tract and promotes normal hydration of the skin tissue so in that and in a nutshell that gives us the functions of thyroid hormone and also again knowing what happens when there's elevated levels of thyroid hormone what does it do it works through a negative feedback mechanism to inhibit the paraventricular nucleus to stop making th but if the thyroid hormone levels are low it'll work through the negative feedback mechanism to stimulate the paraventricular nucleus to make T RH and then more TSH and then more thyroid hormone are an engineer so this was an overview on the thyroid hormone I hope this made sense till next time engineers

Channel: Ninja Nerd

Views: 146,383

Rating: 4.9697938 out of 5

Keywords: thyroid overview, thyroid

Id: 5aq_rxTbtws

Length: 7min 33sec (453 seconds)

Published: Sun Apr 30 2017