 When part of an organ, like the small bowel, pokes into an area it's not supposed to be in, we call that a hernia. When part of an organ intrudes into the inguinal canal, we call that an inguinal hernia. The two places they can occur correlate with the canal's two areas of weakness. If we look at the canal here, it's pretty clear where the areas of weakness are. It's the two holes, the deep and the superficial inguinal rings. If a hernia pops through the deep inguinal ring, it's an indirect inguinal hernia. If it pops only through the superficial ring, like this, we call that a direct inguinal hernia. You can separate them by thinking which one goes in the deep ring, that's the indirect. In males, indirect inguinal hernias can only occur in the setting of a so-called patent processus vaginalis. To give you an idea of what that means, we're going to draw out a single testus here and attach the spermatic cord. So this is what the processus vaginalis is supposed to look like, tightly adhered to the cord and the testus. A patent processus vaginalis looks like this. The result is there's this continuous opening between the peritoneal cavity and the testes. Small bowel can then hop through the deep inguinal ring and as you'll remember from our inguinal canal video, it'll face the strong barrier of TA and IO directly ahead of it. So it'll continue down the inguinal canal and then end up in the scrotum. Some people's processus vaginalis stays patent a little bit, some a lot. The more open it is, the more chance you have of developing an indirect inguinal hernia. Direct inguinal hernias are the result of various risk factors which are relevant to all other types of abdominal hernia. We're going to draw out the layers of the abdomen from this angle to get a better understanding of these risk factors. So I'm drawing out the peritoneum here, behind that is the abdominal contents. In blue we have the transversalis fascia. The deep inguinal ring is a hole in that. We have the con joint tendon, medial reinforcement for the posterior wall of the inguinal canal. Then we have other abdominal muscles in the area as well like the rectus abdominis. So the two major issues that we can face here that can lead to a direct inguinal hernia are increased intraabdominal pressure. For example if you've got ascites which is fluid buildup in the abdomen from chronic liver disease. Or if you've got weakness in any of these layers, most relevant here is the transversalis fascia. If you've got say an inherited deficiency in that. But also general weakness of the abdominal wall muscles makes an inguinal hernia more likely. So if we've got these risk factors ready to go, then a bit of small bowel could overcome the resistance of the peritoneum. The transversalis fascia, the con joint tendon, the abdominal wall muscles. And push all of that with it towards the point of weakness. Towards the superficial inguinal ring. Because it's taking so many of these layers with it, there's a lot restricting its journey. So you won't see a direct inguinal hernia end up in the scrotum, as you can see with an indirect. One more thing before we wrap up. The location of these two types of inguinal hernia are often judged relative to the inferior epigastric vessels, vein and artery. Which are handily located directly in between the superficial and deep inguinal rings. So thanks very much for watching, hit subscribe and we'll see you next time.