Review of GI Anatomy and Physiology (Nursing)

00:00 Hi, I'm Dr.

00:02 Lawes and I want to welcome you to our video on gastrointestinal nursing pharmacology.

00:06 Now we're going to focus on gastritis, peptic ulcer disease and gastroesophageal reflux disease, which you may know as GERD. Now remember, consider having a notebook handy to jot down notes as you watch.

00:18 This is going to really help you reinforce your understanding and make it easier to review the material later. Additionally, you might find it helpful to watch the video twice.

00:27 I know, but listen as repetition greatly aids in your retention.

00:32 If you watch this twice, it's just going to help you that much more.

00:35 Now, these tips are meant to be helpful, and we offer them with the best intentions to support your learning journey.

00:41 So happy studying! Now, to better understand the pharmacology behind these conditions, we need to start with a recap of the anatomy and physiology of the GI system.

00:51 So with a particular focus on the stomach is where I'm going to start first.

00:55 Our gastrointestinal or GI tract is a continuous tube and it runs from the mouth all the way down to the anus. Now each section has a specific role in digestion.

01:05 So when we eat, food enters the mouth or the oral cavity, and then it is sent back into the pharynx.

01:11 Now when this happens, we stop calling it food.

01:14 Now we call it a bolus.

01:16 Now, as the bolus passes through the pharynx, it faces a fork in the road.

01:20 One path leads to the stomach, which we can all agree is the desired route, while the other leads to the respiratory system. Now, if it were as simple as a 50-50 chance of entering either the respiratory or the gastrointestinal system, we'd likely run into trouble, right? So what prevents us from constantly choking? That's right. The epiglottis.

01:41 This cartilaginous gatekeeper springs into action every time we eat, closing the passage to the bronchi so the food can smoothly continue its journey to the esophagus.

01:53 Moving along, pun intended, the bolus travels down the esophagus and eventually reaches the star of this topic.

01:59 It's the stomach. Now we're going to come back to that in a second.

02:03 Once the stomach has completed its task, the partially digested food, now known as chyme embarks on the next leg of its journey.

02:12 It enters the small intestine, a long and twisting tube that can be thought of as the body's nutritional highway. The small intestine also receives assistance from the liver, gallbladder, and pancreas.

02:24 Now this is where the bile and pancreatic enzymes are created, and they help aid in digestion and absorption of fats, proteins, and carbohydrates.

02:34 Okay, so after this thorough processing, the chyme reaches the large intestine or the colon.

02:39 Now this serves as the body's recycling and waste management center.

02:44 The large intestine absorbs water and electrolytes from the remaining chyme, transforming it into solid waste.

02:52 Finally, the journey reaches its end as the solid waste, now called feces, is stored in the rectum.

02:58 When the time is right, the feces make their grand exit through the anus concluding the remarkable journey through the gastrointestinal system.

03:07 Now that we've gone through the different structures that comprise the gastrointestinal system, it's time to, as mentioned earlier, focus on the star of this series of videos, the stomach.

03:17 So think of the stomach as a factory.

03:20 It's located between the esophagus and the small intestine.

03:23 The stomach has three main areas the fundus, the body, and the antrum.

03:28 The stomach's inner lining wears a coat of mucus to shield itself from the acidic environment needed to break down food. However, what cells of the stomach produce this mucus and acid do you know? Let's find out.

03:43 The stomach is a factory with parietal cells.

03:45 They're found in the mucosal lining of the stomach.

03:48 Now, they work really hard to produce hydrochloric acid, simply known as acid.

03:54 Now, this acid is crucial for breaking down food, eliminating harmful bacteria.

03:58 It does some really cool stuff, but I want you to write this down because it will be important later.

04:03 So parietal cells equal hydrochloric acid.

04:09 Another important question we should ask ourselves is how do the parietal cells produce this acid? Well, this is an important question because some of the drugs we're going to discuss affect the enzyme that allows the parietal cells to produce the acid.

04:22 This is the enzyme known as the proton pump.

04:26 It's also known by another name, the hydrogen potassium ATPase, but that's why we call it the proton pump. Now, the proton pump is like a microscopic machine that moves tiny particles called protons from inside the parietal cells and into the stomach.

04:42 Now these protons make the inside of the stomach acidic, which helps us degrade and digest our food.

04:48 So that's it regarding the parietal cells.

04:50 But wait a second.

04:51 How does it come that this acid doesn't destroy our stomach from the inside? Well, that's all thanks to the wonderful mucus producing goblet cells.

05:01 Okay. They're like little guardians creating a protective barrier to defend the stomach lining from the corrosive effects of acid.

05:08 So, once again, I advise you to write this one down.

05:12 Goblet cells equals mucus production.

05:16 Now, finally, the chief cells are another essential part of this factory, as they produce an enzyme called pepsinogen.

05:22 When acid is present, Pepsinogen transforms into pepsin, which helps break down proteins.

05:28 Now, this is a vital step in digestion.

05:31 If something bad happens to the stomach and something bad will happen to it during this series, chief cells could be affected. Now this would lead to an inability to break down proteins, which will make digesting food very difficult.

05:43 So here's another one for you to write down.

05:45 Chief cells equal enzymes that break down food.

05:50 Now before we leave, here's a simple mnemonic to help you remember the cells we discussed and what they do.

05:55 The mnemonic is please give chewing elephant's mighty hugs.

06:01 Okay, let's break that down.

06:03 Please and Hugs represents parietal cells and their role in producing hydrochloric acid.

06:09 Just as a hug can be strong and powerful, hydrochloric acid is crucial for breaking down food and eliminating bacteria in the stomach.

06:17 Give and Mighty stand for goblet cells.

06:20 Now these guys are responsible for mucus production, so imagine giving a mighty gift to someone.

06:26 That's what goblet cells do by creating a protective barrier to shield the stomach lining from the corrosive effects of acid.

06:34 Finally, Chewing and Elephants symbolize the chief cells and their function in producing enzymes that break down food.

06:42 Picture an elephant chewing on a large meal.

06:45 Chief cells help break down those big bites into digestible pieces through the production of the enzymes like pepsinogen. Okay, with this refresher on the stomach's anatomy and physiology, we're now ready to dive into pharmacology of gastritis, peptic ulcer disease, and gastroesophageal reflux disease.

07:04 To further support your understanding of the material, I invite you and encourage you to download our supplementary materials. Now, these resources feature a table summarizing the function of the stomach cells we discussed.

07:15 It's a great study tool.

07:18 Now along with this table, you'll have a custom illustration of the gastrointestinal tract designed just for you. The illustration is perfect for coloring, offering a fun and engaging way to reinforce your understanding. It also has plenty of space for your notes, so don't miss out on these valuable resources that will enhance your learning experience.

07:39 I'll see you in the next video.