what is going on this is mitochosis perfect snatus where medicine makes perfect sense let's continue our biology playlist in the last video we talked about the endocrine glands today it's time to talk about the thyroid gland and the hormones secreted by the fire gland we call them thyroid hormone and they include t3 and t4 which one is more abundant t4 which one is more active t3 the thyroid hormone is like the stove or the oven of your body it lets your body on fire what do you mean by that it boosts your metabolic rate this is my biology playlist where we talk about the basics but if you are a pro check out my endocrinology playlist the ceo gives commands to the general managers which gives commands to the employees which have to listen to the manager others don't listen to the manager and these are the independent contractors who is the ceo the hypothalamus general manager is the pituitary the employees are the thyroid adrenal cortex gonads they listen to the pituitary the independent contractors are parathyroid adrenal medulla not cortex and pancreas today we're talking about one of those employees that has to listen to the boss so here's the ceo the ceo want to talk to the thyroid so the hypothalamus will secrete trh thyrotropin releasing hormone which will go to the pituitary specifically the anterior pituitary this anterior pituitary is going to secrete tsh tsh is going to go and talk to the thyroid gland and the thyroid gland is going to respond by secreting t3 and t4 which one is more abundant t4 that's why t4 can be known as the thyroid hormone hypothalamus increased trh goes to the anterior pituitary to secrete tsh which goes to the thyroid gland to secrete thyroid hormone what if we secreted too much thyroid hormone don't worry about it negative feedback this excessive thyroid hormone is going to inhibit the tr8 from the hypothalamus and it's going to inhibit the tsh from the anterior pituitary let's say that we have a patient who has low levels of thyroid hormone what do you call this i call this hypothyroidism okay now what's the cause of this hypothyroidism it could be a problem in the thyroid gland it could be a problem in the anterior pituitary or it could be a problem in the hypothalamus if the problem is in the thyroid gland we call this primary hypothyroidism if the problem is one step ahead in the anterior pituitary we'll call the secondary hypothyroidism if the problem is two steps ahead we call this tertiary hypothyroidism the end result of all of these is a patient with low levels of thyroid hormone and therefore a low metabolic rate i'm tired i'm lazy i'm depressed i'm obese i'm constipated everything is slow here's your hypothalamus secreting thyrotropin releasing hormone to release what the thyrotropin who's the thyrotropin tsh thyroid stimulating hormone is also known as thyrotropin thyroid stimulating hormone is gonna go and stimulate um the thyroid no duh now the thyroid is gonna secrete thyroid hormone t3 and t4 don't forget that the thyroxine or the thyloid hormone is part of the lipid soluble family as we have discussed before what's the raw material when it comes to the amino acids it's an amino acid known as tyrosine that's the raw material needed to make thyroid hormone there is also another raw material and that's called iodine so in order for you to cook some doozy delicious thyroid hormone you need two components tyrosine and iodine where do i get tyrosine well it's one of the amino acids in your body your body makes tyrosine from another amino acid which is called phenylalanine where do i get phenylalanine from food you eat proteins proteins become amino acids including phenylalanine phenylalanine is going gonna give you tyrosine okay where do i get my iodine from from nature if you live near a sea coast you will get iodine from the sea it's just nature what if i live in the inwards in the desert well you need to eat some iodized salt or anything iodized where's the thyroid gland it's this beauty in your neck what's the name of that that's the arch of the iota what are the three branches that come out of the arch this is brachiocephalic artery formerly known as the arterium inominatum then you have the left common carotid artery and the left subclavian artery let's go to your head let's go to your left arm let's go to your head let's go to your right arm thyroid secretes four hormones t4 that's the main one t3 that's the most active one reverse t3 not active and calcitonin because it will weaken and decrease your calcium level in the blood we'll talk about that in the next video let's dig deeper into the thyroid okay the thyroid has beautiful follicles cool and these follicles are surrounding the lumen of the thyroid think what does it have colloid which is basically a protein thank you so much okay around those follicles you have what para follicular cells cells that are parallel to the follicle wow this is so hard shut up now to the function what's the function of those thyroid follicles they make thyroid hormone that's why we call them a cells the most important cells okay thank you how about the pair of follicular cells they are clear they make calcitonin and we call them the c cells what are the raw materials needed to make thyroid hormone well you need iodine and you need tyrosine where do i find them in my body well there is a carrier carrying them for you and this carrier is called thyroglobin which is a globulin which means it's a protein let's say that i live near the sea so i get some iodide in my body now this iodide is in the blood okay this iodide will go into my thyroid gland thank you and then let's bring one iodide and another iodide let's combine them together to make iodine now the iodine is in my thyroid follicle what do i do with it three things oxidation organification and coupling who's the hero of these three processes a beautiful enzyme known as thyroperoxidase why ace because it's an enzyme why thyroid because it's in the thyroid gland why peroxide because this is a peroxidation reaction let's do this people i had some iodide in my bloodstream because i live near the sea or because i eat iodized salt this iodide is gonna enter into my thyroid gland okay thank you let's trap it and keep it inside the gland otherwise it's gonna go back to the blood all right think and then get one iodide another iodide lump them together now you have iodine or iodine and this is called oxidation that's why you need peroxidase now you see this iodine yeah let's bring some thyroglobulin why because it's the carrier what do you have i have some tyrosine for you get some of that tyrosine plus some iodine and now you have mono iodo tyrosine okay or if you do this twice and bring two of these now we'll have diodo tyrosine and then let's start coupling let's couple one of these with one of these so you have one mono and one dye one plus two equals three thank you so much or you can couple one of these and one of these so two die two plus two is four this is the story of the t3 and t4 try iodo thyronine tetra iodo thyronine and you take those lovely people and put them in the bloodstream so that they can boost your metabolic rate oxidation organification coupling the hero is my thyroperoxidase who secretes tsh the anterior pituitary under an order from home from the hypothalamus what does tsh do stimulates the thyroid gland all right and when i stimulate the thyroid gland i increase the synthesis of t4 and t3 thyroid hormone i also increase the size of the thyroid gland and when the gland in your neck gets larger your neck will swell and we call this goiter okay thyroid hormone do you belong in the insulin world or do you belong to the glucagon world remember the vast majority of hormones are here in the glucagon world which means they are catabolic they break down stuff they destroy stuff to give me some energy i need them in my fasting state insulin alone is here all the other hormones are here growth hormone is dancing in the middle since thyroid hormone is here thyroid is protein catabolic glycogen catabolic triglycerides catabolic your thyroid hormone is catabolic protein catabolic breakdown the protein into amino acids glycogen catabolic break down the glycogen into glucose and lipid catabolic breakdown those triglycerides into small free fatty acids what's the function of thyroid hormone it's the stove of your body it's the oven it increases your basal metabolic rate it boosts your metabolism raising your body temperature increasing your oxygen consumption it's very important for brain development especially during embryology and during childhood that's why patients who suffer from congenital hypothyroidism have low iq thyroid hormone belongs to the glucagon world who else belongs to the glucagon world catecholamines epinephrine nor epinephrine dopamine etc therefore thyroid hormone is gonna help his family i'm gonna help catecholamines help them do what i'm gonna increase the number and the sensitivity of the beta receptor so that when the catecholamine comes and binds to the beta receptor you get more catabolic activity thyroid hormone will boost the ovarian cycle and females it's going to boost spermatogenesis in males and that's why if you have very low thyroid the hormone you can get what infertility menstrual irregularities etc also thyroid hormone is going to increase your gastrointestinal motility and therefore if you have too much thyroid hormone called hyperthyroidism you get diarrhea too much motility but if you have hypo thyroidism too little thyroid hormone you get constipation no motility now if you're just getting started focus on the symptoms don't try to focus a lot on this because you'll lose your mind so let's compare between hypothyroidism and hyperthyroidism symptoms hypothyroidism everything is slow hyperthyroidism everything is super fast hypo let's go heart is slow called bradycardia how about i i'm like can i tolerate cold no you can't because you have no metabolism cold intolerance you're always cold constipated your gut is not moving coarse hair your hair is not silky depression dry yellow skin mexidima menoraja lethargy loss of the outer one-third of the eyebrow no one knows why it could be because you get coarse hair and the hair on the outer third of the eyebrow is like more vulnerable or something so you lose it hoarseness of voice weight gain you're sad you're lazy you're obese you're slow you're depressed you're constipated you're cold you're so lethargic but on the other hand if you're hyperthyroid look at this tachycardia increase heart rate nervousness am anxious i'm sweating i'm staring at you i have tremors in my hand i'm heat intolerant i have diarrhea right now i can ruin your life i have warm moist that's the only thing that's good my skin is lovely and my hair is silky but my neck is super large goiter and i'm staring at you with my eyes bulging outwards exothelms but on the bright side i lost weight because my metabolism is super duper fast what's the cheapest way to diagnose hyperthyroidism oh mri of the brain oh shut up the cheapest ways to ask for an old driver's license or an id here is sam in the past here is sam now what happened to sam hyperthyroidism what if sam was like this in the past but is like this right now it could be hypothyroidism but however causes wouldn't the patient notice the change no because it's very gradual the patient will not notice but when you put the two pictures next to each other everyone will notice poor sam also poor um kel'thum um kel'thum was a famous egyptian singer she developed hyperthyroidism and she was really sad about this because if you're a singer and you're sweating if you're having tremors palpitations weight loss diarrhea inc that's not good the only thing that was good for her uh silky hair of course who else is gonna tell you these stories your woke professor with his theories oh give me a break if you like this video check out my renal physiology course on my website medicosisperfectnetis.com i also have an endocrine pharmacology course and we have extended this discount you can get 40 discount off anything on my website just use discount code kidney me all your juxtaglomerular nephrons be intact thank you for watching please subscribe hit the bell and click on the join button you can support me here or here go to my website download my courses be safe stay happy study hard this is medicos's perfectionist where medicine makes perfect sense