Positions of the Organs in the Abdomen

00:01 Now let's have a look at the location of various important organs within the abdomen.

00:05 And let's start off with the liver.

00:08 As we can see here, the liver occupies a large portion of the upper aspect of the abdomen.

00:13 And if we add in the midaxillary line here on the right hand side, you can see we have the right border of the liver extending all the way down to the 10th costal cartilage on the right hand side.

00:25 To the 10th costal cartilage from the 10th rib on the right hand side.

00:29 And it extends all the way across to the left midclavicular line.

00:33 Remember those midclavicular lines were separating the abdomen into those nine regions, which we spoke about previously.

00:41 Here, we can see the left aspect of the liver extending all the way towards the midclavicular line on the left hand side.

00:48 It runs approximately to around the sixth rib.

00:51 Again, on the left hand side.

00:53 So on the right hand side, we can see it extends down to the 10th costal cartilage on the right, and on the left hand side, we can see it extends all the way across to the sixth rib.

01:03 Connecting those two points, we have the inferior border of the liver.

01:07 And this is typically what happens when the lungs are fully inspired.

01:11 You got your chest full of air, and that actually forces the liver inferiorly slightly.

01:16 And as you breathe in and out, if you were to place a finger just underneath the costal cartilages, you may in fact feel that inferior border of the liver, just brushing against your fingers.

01:28 If we include the midclavicular line on the right hand side, we can see how it actually extends all the way up to the fifth rib on the right hand side.

01:35 And again, adding the left midclavicular line over on the other side at the level of the sixth rib, you can see we've created that superior border of how it's running across the superior aspect of the abdomen.

01:47 And it actually feels quite high if you remember where your xiphisternum is, that is approximately where the superior border of the liver is located.

01:55 Then connecting the fifth rib all the way down to the 10th rib on the right hand side, we have the right border of the liver.

02:03 So we can see the liver is a really large organ that occupies a large aspects of that upper right quadrant of the abdomen.

02:11 Just peeking underneath the inferior border of the liver, we have the gallbladder which can be quite variable in size.

02:20 But typically it'd be located around the ninth costal cartilage.

02:24 So we can see the gallbladder just peeking out from its location under the inferior border of the liver.

02:30 If we introduce the stomach into the image, then you can see how the stomach is contiguous with the esophagus.

02:35 Here, where we have the gastroesophageal junction, and you can see how the esophagus deviates over to the left hand side as the esophagus then becomes like I said, contiguous with the stomach.

02:47 And this happens approximately at the seventh costal cartilage but noting how it's drifted to the left, it is the left seventh costal cartilage.

02:56 We can then see the body of the stomach.

02:58 Just take that away and see it in green.

03:01 We can see how the stomach not as big as the liver, but still occupies a nice couple of regions from the left hypochondriac region all the way to the central region which is the epigastrium.

03:12 If we will then to see how the stomach moves across the vertebral column onto the right hand side just highlighted in green.

03:19 Here, we can see how it begins to form the duodenum.

03:23 So the duodenum leaves the stomach as it causes across the vertebral column.

03:27 And we can see here, the first are four parts of the duodenum.

03:30 And this is at the level of the transpyloric plane.

03:33 So the pylorus is that thickened aspect of the inferior aspect of the stomach that becomes continuous as the duodenum.

03:41 And this is the first part of the duodenum.

03:42 And that comes to the transpyloric plane.

03:46 The second part of the duodenum runs inferiorly.

03:50 And it runs from the second to the third lumbar vertebrae.

03:54 So the second part of the duodenum runs inferiorly from the second to the third part of the lumbar vertebrae.

04:00 And then we have the horizontal portion, which is running across the third lumbar vertebrae.

04:05 Finally, as it ascends into the fourth part of the duodenum, which goes back up to L2.

04:12 So it's quite complicated there.

04:13 Four aspects of the duodenum.

04:15 We've got the first part of the transpyloric plane, the second part, which runs L2 to L3 inferiorly.

04:22 Before you have the transversal, the horizontal aspect of the duodenum, its third part.

04:27 And then ascending back up to the second lumbar vertebrae, forming this kind of C shaped arrangement.

04:34 Let's quickly then just move on to the appendix because we cover the large intestine in the small intestine, in great detail later on.

04:41 But here we can see the appendix.

04:44 And we need to remember some of those surface features to locate the appendix.

04:48 Here we have the anterior superior iliac spine.

04:50 And here we'd have the umbilicus, which has been projected onto the bony aspect.

04:55 And if we were to draw a imaginary line, diagonal line passing from the umbilicus to the anterior superior iliac spine, two thirds of the way from the umbilicus.

05:06 So two thirds of the way from the umbilicus to the anterior superior iliac spine, you would locate McBurney's point.

05:14 And that is where the appendix would be located.

05:17 If we then spin the body around, we can see up from its posterior aspect, We can see a paired organ to the two kidneys.

05:24 And then on the left hand side, as we're looking at the posterior aspect of this model, we can see the spleen.

05:31 We've also put T11 through to L4 on the vertebrae there.

05:36 indicating the various vertebrae of the vertebral column.

05:41 The right kidney is much lower than the left kidney.

05:43 We can see it typically sits at the level of the first to the fourth lumbar vertebrae.

05:49 And that's because of the large liver that pushes the kidney inferiorly.

05:53 On the left hand side, we can see a kidney again highlighted And this is slightly higher, because we don't have the mass of liver pushing it inferiorly.

06:00 This is the left kidney that runs from around about T12 down to L3, L4.

06:06 This is going to be highly variable from individual to individual.

06:09 But typically, these are the sorts of locations that you can try and palpate these organs if you were to try and feel them through the surface of the abdomen.

06:18 So we have our paired organ, either side of the midline, our two kidneys, left and right.

06:22 And then, finally, really sitting above the kidney there we can see the spleen.

06:27 And that is positioned really sitting against those 9, 10, 11 ribs that you can see there.

06:33 And it is pushed quite tightly against those ribs.

06:35 So any fractures of those ribs quite superficially can actually rupture the spleen, and lead to a lot of bleeding out into the abdominal cavity.

06:44 So various organs that can be palpated through the surface of the skin.

06:49 And it's important to understand where they are located.

06:53 So finally then, if we were to just make a few incisions through the abdominal wall, what structures would we find? So here we have the anterior subcostal incision, that's following the curvature of those costal cartilages.

07:06 And if we were to make an incision in that direction, we typically find the gallbladder and the liver.

07:12 Here again, we have McBurney incision, and that's two thirds of the way from the umbilicus to the anterior superior iliac spine.

07:19 And then, you'd find the appendix.

07:22 Here we've got the right inguinal incision, and typically you can locate the inguinal canal, the spermatic cord, the round ligament of the uterus in a female, if you were to make an incision in this direction, And then, the Pfannenstiel incision or the suprapubic incision is typically what's done if a cesarean was going to be undertaken to take the baby out during pregnancy.

07:46 Various other midline incisions can be made typically through the linea alba.

07:50 Although that can cause problems because the vasculature to this region is not great.

07:54 So healing it can cause a problem.

07:56 But midline incisions can be done for various laparotomy procedures that are taking place.

08:01 So enter into the abdomen to access the stomach, the small, the large intestines, the pancreas, etc.