Digestive System | Ultimate Review | From A to Z | Gastroenterology Medicosis Perfectionalis (GI)
What is going on everybody what is cracking racking this is medicosis perfectionist where medicine makes perfect sense let’s resume my biology playlist for the last several videos we have been talking about your digestive system what if we can put it all together in one humongous video if you have watched my previous video this will make perfect sense to you if
This is new to you back up calm down and watch my previous videos first because we’ll go very quickly again this is part of my biology series what is digestion digestion is the conversion of big macromolecules into tiny micro molecules after you digest it’s time for you to absorb no digestion no absorption who is the absolute hero of digestion the answer is the
Pancreas especially the exocrine pancreas the pancreas alone can complete the entire process of digestion from a to z i’m talking about the exocrine pancreas of course particularly the aciness of those glands what is food carbohydrate protein and fat the purpose of digestion is to convert them to from big molecules into small molecules from this big carb molecule
Into tiny monosaccharides same thing for proteins and fats after you break them down into teeny tiny molecules now it’s time for you to go to work eventually they become silk a boom tca cycle boom energy that’s why we eat digestion is to break down the big macromolecules into smaller micro molecules that can pass through membranes and be absorbed so the starch
And glycogen are broken down into monosaccharides glucose fructose galactose the big protein macromolecules are broken down eventually into amino acids and the big triglyceride fats are broken down into free fatty acid and two monoglycerol whenever we mention fat we should also mention the fat soluble vitamins let’s go from head to toe or from mouth to anal canal
Let’s talk about your mouth mechanical digestion and chemicals what do you mean by mechanical mastication all right these are skeletal muscles voluntary action chemical this is salivation don’t forget your salivary amylase and salivary lipase amylase is for carb digestion lipases for lipid digestion this lovely amylase is gonna digest carbohydrates such as starch
From plants or glycogen from animals into maltose and dextrin who’s gonna break down maltose then this is the role of your small intestine because it has an enzyme known as maltase but that will be way downstairs who makes the saliva your salivary glands and you have three pairs of major salivary glands the mouth will send that bolus of food into the esophagus via
The pharynx in a process known as swallowing your esophagus has three thirds upper third voluntary lower third involuntary and the middle is kind of ah in between how does the food move downwards via peristalsis after your esophagus there is the stomach mechanical and chemical motility and secretion myenteric versus submucosal plexus who stimulates mechanical and
Chemical digestion the parasympathetic nervous system ie vagus nerve and who inhibits motility and secretion sympathetic nervous system i.e greater splenic nerve stomach contains parietal cells to secrete the acid and the intrinsic factor the asset is to clean stuff and to convert pepsinogen which comes from the chief cell into pepsin pepsin will help you digest
Proteins the intrinsic factor will help you absorb vitamin b12 next g cells secrete gastrin which is pro gastric motility and secretion this is the only gi hormone that is pro-stomach all the other doofuses are anti-stomach the stomach contains mucous glands containing goblet cells to secrete mucus to protect the stomach wall from the acidity of the cavity of
The stomach next we have delta cells for somatostatin the doofus who is a universal inhibitor and enterochromafin-like cells which secrete histamine which stimulates the lovely parietal cells to make more acid if a family member of yours had heartburn before and went to the store to pick up some pills odds are these spells work by inhibiting the receptor of that
Histamine and therefore the parietal cell will make less acid ergo less heartburn hopefully after the stomach we have the small intestine mechanical chemical and absorption mechanical motility same thing chemical secretions what do we secrete please gi enzymes and gi hormones these gi enzymes will help us digest carbohydrates and proteins but not necessarily fat
The gi hormones are pro motility and secretion first we’ll talk about the gi enzymes from the intestine and they’ll talk about the hormones gi enzymes from the small intestine to digest carbohydrates and to digest proteins so i just carbohydrates i have the maltase isomaltase lactase and sucrase maltase digests maltose into two molecules of glucose isomaltase is
Very similar lactase will convert lactose into glucose and get lactose so craze will digest sucrose into glucose and fructose now let’s digest proteins there is the peptidase to break down big peptides into smaller amino acids there is a dye peptidase to break down dipeptides into amino acids and there is my hero entero peptidase not only it breaks down peptides
It also converts trypsinogen into trypsin and pro-carboxy peptidases and b into carboxy peptidases where did trypsinogen come from from the pancreas how about pro-carboxy peptidase also from the pancreas these are inactive but the intrapeptidase will convert them to their active counterparts next let’s talk about gi hormones most of them come from the upper part
Of small intestine gastrin comes from the stomach and upper part of small intestine gastrin is secreted by g cells in the stomach and its probe motility and secretion of the stomach secretin is from the s cells in the upper part of small intestine it goes to the pancreas endocrine or exocrine exocrine pancreas asanas or duct duct cells and tell them to secrete
Humongous amount of secretions rich in water and bicarbonate to neutralize the acidity that’s being dumped upon us from the acidic stomach because all of the enzymes in your body need to work in a slightly alkaline environment with the exception of mr pepsin next cck cholecystokine and pancreas i mean why do you call it cholecystokinin because they will cause movement
Of the choli cyst i will squeeze that gallbladder dish the bile out into the dewater why do you call the eubank creozymon because i’ll secrete enzymes from the pancreas oh that makes sense which part of the pancreas endocrine exocrine exocrine are you talking about the essence or the duct i’m talking about the essence what are you secreting water and bicarbonate shut
Up that was secretin i will release those digestive enzymes also into the duodenum this will help you digest proteins carbohydrates and fat the bile will help you emulsify the fat hey minericosas this is so much information it’s making my stomach turn no pun intended then somatostatin is for you it’s a universal inhibitor it inhibits everything it inhibits motility
It inhibits secretion it even inhibits its own secretion this doofus comes from the delta cells or the d cells don’t forget to review your anatomy which we have discussed before pause and review the pancreas alone can complete the process of digestion from a to z we’re talking about protein carbohydrate and fat digestion which part of the pancreas are referring
To when it comes to digestion endocrine or exocrine exocrine duct or asanas as of course who is boosting this secret inner cck cck the pancreas can help you digest proteins fats and carbohydrates protein digestion pancreas decreased trypsinogen and pro-carboxy peptidases a and b chymotrypsinogen is very similar to trypsinogen is going to convert the inactive into
The active enteropeptidase why did we secrete them as in act why not just secrete the active form from the beginning because if the pancreas secrete the active form the pancreas will digest itself oh that will be horrible so we will wait until we reach that duodenum lumen so that we get activated by the duodenal enteropeptidase intermeans coming from the intestine
Now we have the active forms the active forms will help you digest proteins next fat digestion the pancreas secretes lipase and coli paste and phospholipase and cholesterol estrace break down those big fats into smaller molecules such as free fatty acids and two monoglycerols pancreas will help you digest carbohydrates as well break down the starch or the glycogen
Into maltose here is the role of the pancreas we have non-fat digestion what do you mean by non-fat carbs and proteins for carbs i have mlas for you for proteins there is trypsin chymotrypsin carboxy peptidase a carboxy peptidase b and other proteases how about for lipid well now we’re talking we have lipase coli paste cholesterol strains and phospholipase pause
And review just don’t forget that the pancreas has chemical digestive functions but the liver slash gallbladder ie bile has mechanical digestive function what do you mean by mechanical i mean emulsification of fat bile is not an enzyme and that’s why i love cck very much choli cystokine and pancreazimon before you know it you will digest emulsify and absorb fat and
Fat soluble vitamins now let’s review each macromolecule alone carbohydrates alone and then proteins and then lipids carbs alone start with the big ones starch or glycogen and then thanks to the amylase from the saliva and from your pancreas we have maltose and isomaltos thanks to the maltase from the small intestine will have two molecules of glucose alright how
About if the carb was milk then it contains lactose thanks to lactase from the small intestine you end up with glucose and get lactose sugarcane contains sucrose sugar thanks to sucrase also from the small intestine you have glucose and fructose fibers are carbohydrates they are non-digestible carbohydrates why because they contain cell wall of those plants cell
Wall contains cellulose and your body does not contain cellulase enzyme you cannot digest them they will make a bulk they will remain in your intestine until they end up in the stool what’s good about that is that they will attract water by osmosis and therefore they can help you mitigate and alleviate and ameliorate the symptoms of constipation we’re done with
Carbs let’s talk about protein digestion you can say thank you to your stomach especially the sheaf cells which made the pepsinogen but pepsinogen is inactive who’s going to activate it hydrochloric acid which came from parietal cells pepsin will help you digest proteins now we have polypeptides polypeptides are going to go to the duodenum in the duodenum we have
Chymotrypsin elastase carboxy peptidase don’t forget to say thank you to your pancreas especially to trypsin but you cannot say thank you to trypsin without saying thank you to the small intestine enteropeptides formerly known as enterokinase so let’s take a deep breath and do this again the pancreas secretes strep centers right inactive who’s going to activate
Tryptophan interception in turo peptidase where the flip that has come from from the entero from the intestine i get it now trypsin is active true yep trepsin will activate his brothers which also came from the pancreas now you have activated chymotrypsin elastase carboxy peptidase break down those polypeptides the small intestine will chime in not only with the
Enteropeptidase but also with aminopeptidase and dipeptidases break them down baby and now we absorb those teeny tiny amino acids pause and review we’re done with carbs we’re done with proteins let’s talk about fat this is the fat that’s contained in the diet in order for you to absorb fat or fat soluble vitamins you need three organs to be normal and intact and
Healthy one liver and biliary system two pancreas three the gut which will do the actual absorption if you’re absorbing anything but fat i mean carbs i mean proteins you will go through the blood vessel route because these are water soluble and your blood is made of plasma which is basically water but if you’re talking about absorption of fat you’re not going to
Blood vessels you’re going to lymph vessels known as lactails and this is the story of the micelles thank you so much bile this is the story of the packages known as chylomicrons the lipid is in the interior protein is on the exterior lipid soluble in water soluble out before you know it we are in the lymph capillaries and then lymph vessels take me back to big veins
After i clean all of this from toxins this is the story of bile salts they are amphibatic hydrophilic and hydrophobic hydrophilic on the outside the water near the water near the protein but the inner is hydrophobic i.e lipophilic it loves fat put the fat next to the fat this is the story of the mycel then chylomicrons then lymph capillaries bigger lymph vessels
Afferent lymphatics lymph nodes efferent lymphatics big veins right atrium to digest and absorb fat you need pancreas and gall bladder and an intact gut wall don’t forget this is necessary to absorb the fat and the fat soluble vitamins vitamin k e d and a now here is everything you need to know about digestion in one beautiful slide let’s talk about carbohydrate you
Need your salivary amylase pancreatic amylase and intestinal maltase isomaltis lactase and socrates before you know it the big carbs are now micro molecules glucose galactose and fructose you can absorb these proteins require gastric pepsin which is dependent on the hcl pancreatic trypsin chymotrypsin carboxy peptidase elastase other proteases etc why do we call it
Carboxy peptidase because it removes the carboxyl group the carboxyl terminus of the protein or peptide contrast that with the amino peptidase which is going to remove the amino or the n terminus of the peptide oh i get it that’s why carboxy peptidase versus amino peptidase the c and versus the n terminus the intestine will give you amino peptidase entero peptidase
And dye peptidase before we know it the protein macromolecules became amino acid micro molecules you will absorb these when it comes to fat we start with big fats such as triglycerides you will need salivary lipase pancreatic clipase coli paste phospholipase cholesterol esterase you will need bile acids bile salts which make the mycells the amphibathic structures
And then we broke them down into fatty acids and two mono cholesterols you will absorb these pause and review bring a piece of paper and write everything here down repetition is the mother of pedagogy this was gi biology if you want gi pharmacology i have an utercoids pharmacology course on my website i also have a renal physiology course at miracosisperfixnet.com
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Transcribed from video
Digestion | Ultimate Review | From A to Z By Medicosis PerfectionalisliveBroadcastDetails{isLiveNowfalsestartTimestamp2022-07-21T214302+0000endTimestamp2022-07-21T220301+0000}
