 Okay, so this is the left side of the cadaver and we have decided to show the entire lumbar plexus with the branches of the lumbar plexus. In order to understand the lumbar plexus, we have to remember that most of the lumbar plexus is formed within the layers of the suas major muscle. So therefore, this is the suas major muscle on the left side and on top of that is the suas minor. So we have split the suas minor and we have split the suas major and this is the deep part of the suas major and once we do that we can see that the lumbar plexus is completely exposed here between the layers of the suas major. So let's take them part by part. This root that we see here this is the L2 root. This root that we see is the L3. This is the L4 root and this is the L5 root and then the lumbar plexus is being formed here. Having mentioned that let's take a look at the branches of the lumbar plexus. Let's go a step higher. We will start from here. This is the 12th rib and above that this is the 11th rib. So therefore, this is the 11th intercostal space and we have gone a little above to pick up the 11th intercostal nerve and we can see it here. This is the 11th intercostal nerve. This being the 12th rib, this is a part of the subcostal nerve that is T12 and this is the subcostal vessel which we can see here. The posterior subcostal artery and vein. This is one cut portion of the subcostal nerve and this is the other portion of the subcostal nerve. Now let's come to L1. This is one portion of L1. Some books say that L1 is not part of the lumbar plexus. Well, some books consider it as part of lumbar plexus. So this is L1 and this continues down and it splits into two parts. The iliohypogastric and the ilioinguinal. The iliohypogastric, it supplies the transverse abdominis and the internal oblique and it supplies the skin above the inguinal fold. It does not go beyond the abdomen. The ilioinguinal also supplies the same two muscles, but it also continues and here we will see we have opened up the inguinal canal to show you this is the inguinal canal on the left side and we can see that the ilioinguinal nerve then travels in the inguinal canal. This is the ilioinguinal nerve. It travels in the inguinal canal and from here it goes into the scrotum. Here it becomes known as the anterior scrotal nerve or the anterior labial nerve in the case of females and it also supplies the skin of the upper medial aspect of the thigh. The ilioinguinal nerve serves as the afferent lip of the cremaster reflex. So that is about L1. Now let's take a look at the next. That is the genital and the femoral, the genitofemoral nerve. So now I'm in the left inguinal canal. I've opened up the sphermatic cord and we can see that this is the nerve which I've picked up here and I'm pulling from here. This is the genital branch of the genitofemoral which runs in the sphermatic cord and this supplies the cremaster muscle and it serves as the efferent limb of the cremaster reflex. In the abdomen it runs on the surface of the soas major muscle. And the femoral component of the L12 it supplies the upper anterior aspect of the thigh. So that's about L12. Now let's come to the other branches of the lumbar plexus. We can see this big nerve here and we can see the origin of this nerve. When I lift up the this is the femoral nerve. L234 posterior division. This L234 it runs in the muscular compartment in the sub inguinal space where my finger is gone in along with the tendon of the iliangus and the soas. And it supplies the entire anterior aspect of the thigh, quadriceps muscles. It also supplies the skin of the anterior aspect of the thigh and a little bit of the medial aspect of the thigh. And the femoral and the saphenous branch goes all the way to the foot. So this is the femoral nerve. The next branch that we see here is this one. This is the obtrator nerve. This is also L234 it goes into the pelvis and from there it comes out through the obtrator canal and it goes to the supply the muscles of the medial compartment and the skin of the middle medial part of the thigh. The difference between this and obtrator is that obtrator is the anterior division of L234. And finally we have this here and it's this one. This is the lumbosacral trunk L4 and L5 which goes into the pelvis and participates in the formation of the sacral plexus and contributes to the sciatic nerve. This is yet another part of the same lumboplexus. This is the lateral femoral cutaneous nerve. It arises from L234. This also runs under the inguinal ligament. The lateral part of the inguinal ligament and it supplies the skin of the anterior lateral aspect of the thigh in this region. Here there is an important clinical correlation. This nerve can get entrapped under the lateral part of the inguinal ligament and produce pain, numbness and tingling on the anterior lateral aspect of the thigh. The condition being known as merigia peristhetical. So these are all the branches of the lumboplexus. So let me quickly recap. We have the L1 iliohypogastric, ilioinguinal. Then we have genitofemoral which runs in the lumbomatic cord. Lateral femoral cutaneous nerve, obtrator nerve, femoral nerve. Femoral nerve, lumbosacral trunk. So these are the various branches of the lumboplexus. And here there is a mnemonic. If you consider i as 1 and there are two i's, ilioinguinal, iliohypogastric. We can say once, twice, get, g, genitofemoral, laid, lateral femoral cutaneous, on obtrator, Friday femoral and later lumbosacral trunk. Once, twice, get, lay on Friday and later. These are the branches of the lumboplexus. Thank you very much for watching. Dr. Sanjay Sanyal, have a nice day.