 This is a demonstration of the inguinal canal This is the left side of the cadaver The right side of the cadaver Inguinal herniography had already been done. So therefore the anatomy was highly distorted. Therefore we chose the left side of the cadaver The equal canal is a canal approximately one and a half inches long One inch above and parallel to the medial two-thirds of the inguinal ligament So this is the approximate location of the inguinal canal This is a potential area of weakness Where the descending test is produced a weakness in the anterior abdominal wall and this is a very important and a very common side of Inguinal hernia in especially in meds. In fact inguinal hernia surgery is one of the most common Surgeries worldwide elective surgery We will think of the canal as a rectangular box with an anterior wall Roof a posterior wall and a float an external ring and an internal ring So let's split the anterior wall and this is the anterior wall which we have split So this is the external oblique aponeurosis This is one leaf and this is the other leaf So we have opened the inguinal canal So the anterior wall is formed by the external oblique aponeurosis But the lateral part of the inguinal canal anterior wall is also formed by The internal oblique and we have split that also because we know that the internal oblique also takes origin from the inguinal ligament So this is the anterior wall part of the anterior wall Once we have split then we see the contents of the canal and what do we notice? We see this nerve here running on the inner surface That's the first structure that comes to our view in setting one canal. This is the illiowing one The illiowing one of love it supplies the internal oblique and the transfers of prominence And we can see it is piercing through and it supplies and it further continues And it goes and supplies the scrotum and the thigh and it serves as an Afferent limb of the cremaster reflex. So let's reflect of the illiowing one on nerve in the root of the scrotum, we have lifted up the Spomatic cord and we can see that the spammatic cord is running through the inguinal canal Let me reflect the spammatic cord to show you the floor of the inguinal canal This upturned margin of the inguinal ligament that we see here This is the poo part ligament This is the floor of the inguinal canal and further medially There's a sharp edge of the floor and that is called the Lacuna ligament that also forms part of the floor of the inguinal canal Now let's take a look at the roof of the inguinal canal for that. I would draw your attention to these muscle fibers here This is very important We can see some curving muscle fibers here This is got a separate name. This is called the conjoined muscle or conjoined tendon This conjoined muscle or conjoined tendon is actually a combined muscles of both internal oblique and transverse abdominis Those fibers which took origin from the inguinal ligament So they curve like this and they form the roof So we can see they're forming the roof of the inguinal canal the conjoined muscle and there is yet one more structure That is called the iliopubic tract, which is the inferior free margin of the facial transversal is So these two structures of the roof of the inguinal canal now I'm going to Reflect the cord structures to show you the posterior wall of the inguinal canal The posterior wall of the inguinal canal is formed by this thin membrane that you see here This is the facial transversal is this forms the entire posterior wall additionally the posterior wall is also formed by the reflected inguinal ligament Which is a portion of the inguinal ligament which moves upwards and medially and fuses with the rectus and And finally the same conjoined muscle and tendon which form the roof It goes behind and it also forms the part of the posterior wall So therefore we will remember the rule of two Anti-wall is formed by two structures external oblique internal oblique Flow is formed by two structures who part ligament and argument ligament roof is formed by the conjoined Tendon and the illiopubic tract The only exception to the rule of two is the posterior wall which contains three structures namely again the conjoined tendon The facial transversal is and the reflected inguinal ligament, which is only in the medial one fourth Now I will show you Two other components of the inguinal canal namely the external and the internal ring for that Let me bring these two together the two leaves of the external oblique We can see that this was the opening. We have split it open through which and I brought them together now This is the opening through which this spoma de cord was passing. This is called the external ring The external ring is an opening in the external oblique aponeurosis through which the spoma de cord passes And the external ring is got two crusts a medial crust Which is attached which gets fused with the rectus sheath and And the lateral crust which gets attached to the pubic tubercula. So, this is the medial crust This is the lateral crust This is the external ring and the external ring gives an expansion which is called the external spomatic fascia We can see it here So, this is the place where the spoma de cord exits the inguinal canal and enters the scrotum Now let's take a look at internal ring. So, for that again I have opened the inguinal canal and We can see the contents of the spoma de cord. Let's lift up this content This is the ductus difference and we can see the ductus difference in this portion when I pull here It moving here and when I pull here is moving. This is the one which can Transfers the spoma de cord and we can see the ductus difference is disappearing in an opening here This is the internal ring The internal ring is an opening in the fascia transversalis and where is the location of the internal ring? It is located one inch above the mediguinal point when we feel the femoral artery pulsation The next structure which is passing through the internal ring Please this is the testicular artery and the testicular veins Apart from these two ductus difference and the testicular artery what else do we see? We see another nerve and I will show you the nerve just now. This is the nerve This nerve is not passing through the internal ring. It is passing through the spoma de cord. This is the genital femoral nerve The genital femoral nerve supplies these muscle fibers that we see here These muscle fibers are known as cremaster muscle This cremaster muscle is derived from the conjoined muscle and The genital femoral nerve supplies the cremaster muscle and serves as the efferent limb of the cremaster reflex And then it goes to the thigh and the scrotum. So, this is another content of the inguinal canal Next important point to be noted Again, let's come back to our internal ring. This is the internal ring and my forceps disappeared in the internal ring Internal ring. Let me repeat again is an opening in the fascia transversalis and going through the internal ring We can see the ductus difference and going through the internal ring. We can see the testicular artery and vein This is the fascia transversalis. This is the fascia transversalis here. I picked it up here This constitutes the posterior wall. I told you that you can see the fascia transversalis I made a small opening in the fascia transversalis to show you a very important structure and I have lifted it up here This is the inferior epigastric artery and vein. This is the inferior epigastric artery and the inferior epigastric vein Normally it is running behind the fascia transversalis. I had split open this fascia transversalis to show you the inferior epigastric artery Please note. This is a very important relationship The inferior epigastric artery is medial to the internal ring Inferior epigastric artery is medial to the internal ring. So that brings me to the final point Inguinal hernia. An inguinal hernia is when a Fold of peritoneum pushes out through the internal ring and takes a loop of indistinct with it And it runs within the inguinal canal. That is known as an inguinal hernia And when it comes through the internal ring and comes out like this then it is known as indirect inguinal hernia But there are some other hernias which do not come through the internal ring instead They come medial to the inferior epigastric artery. They push directly through the fascia transversalis here they push directly and They enter the inguinal canal That is known as a direct inguinal hernia. So the carry-home message is an indirect inguinal hernia is located lateral to the Inferior epigastric artery and a direct inguinal hernia is located medial to the inferior epigastric artery and How do we know this is the inferior epigastric artery? For that I will reflect this rectus abdominis And once I reflect this can we see the epigastric artery running inside and when I exert traction here We can see this is the inferior epigastric artery So the inferior epigastric artery is the one which runs in the fascia transversalis and it enters into the rectus sheath here so this is the quick and a brief overview of the inguinal canal and its contents and the location and source and the pathogenesis of an indirect inguinal hernia and a Direct inguinal hernia. Thank you for watching Dr. Sanjay Sanyal