Overview – Gastrointestinal System

00:01 To be able to talk through where these occur, there are two different kinds of approaches we could take.

00:06 The first approach is the anatomical approach.

00:10 So for this, you take in food through the mouth, you’ll swallow it into the esophagus.

00:15 It will go into the stomach and then small intestine, large intestine, then out through the rectum if you didn’t utilize it or absorb it.

00:24 And I like this anatomical viewpoint because it gives a very nice link through the anatomy.

00:29 But in terms of function, I think it’s better to start thinking about this in terms of an engineering point of view.

00:36 So let’s take a look at what that might look like.

00:39 So this engineering tube viewpoint sets up this type of system in kind of a linear format.

00:45 We’ll start off with some thing like the teeth, which will chop up food.

00:52 We will end up adding liquid and adding mucus to lubricate the system and to get the food stuff along the passageways.

01:01 You will have a portion of it that helps blend or grind up the food as well as provide the acid for undergoing certain types of protein denaturation.

01:12 We’ll have a certain portion of this engineering tube that will supply detergent.

01:18 A place in which all those reactions can take place.

01:23 And then we’ll have a specific component that will add then enzymes to go undergo a lot of the different macronutrient digestion.

01:32 But of course, we need to have a spot in which we can absorb all of these particular macro and micronutrients.

01:42 Finally, to be able to save water, we need to have a place where we can remove water and we can form pellets so that of course, we can get rid of certain things that aren’t necessary.

01:54 So this is this engineering tube viewpoint that we’re going to revisit a number of times as we introduce the various components of the gastrointestinal system.

02:04 And I think this functional approach will really help land what kind of things happen at what spot.

02:10 Okay, let’s start linking the two and that is the engineering and the anatomical viewpoints.

02:17 Let’s start off with where this detergent is added from.

02:20 And that is done from the liver and from the gallbladder.

02:23 So the liver is going to produce various types of substances that are stored in the gallbladder and then released into the small intestine.

02:31 So that’s where the detergent is coming from.

02:36 The mouth and teeth provide this kind of initial chopping and grinding of food.

02:40 And why that’s so important is you’re taking large particles, making them into smaller particles so there’s more surface area available to undergo digestion.

02:50 But remember to be able to get food down the GI system, we need to make sure that it has water added to it and it also is lubricated and that’s done with the salivary glands.

03:03 Finally, the stomach is the place in which we’re going to help blend and grind food a little bit more.

03:07 And this is where acid is added to the system.

03:11 Finally, it’s your pancreas that supplies the enzymes to the small intestine and these enzymes include everything from those involved with carbohydrates, fats, and proteins.

03:24 The small intestine involves the area in which most all of the action is taking place for digestion and absorption.

03:33 So these are where the enzymes are acting on and where you break these large molecules down into small molecules, so that you can absorb them.

03:42 Finally, the large intestine is where we remove some water.

03:46 And then finally, the rectum is of course where we control what is released from the gastrointestinal system.