 This is going to be a demonstration of the branches of the lumbar plexus. This is a supine cadaver I am standing on the left side camera person is on the left side first We will demonstrate the nerves on the left side and then we will show it on the right side Let's start off with the subcostal nerve here. This is below the 12th rib. That's why it is called subcostal This is T12 This was actually under the fibers of the diaphragm which we have cut and reflected we will show you on the right side This is the subcostal nerve on the right side under the 12th rib on the right side. These subcostal nerves They supply the anti-abdominal muscles namely the external oblique internal oblique Transverses of dominus the next nerve that we can see here is this one which I picked up here This is the L1 the L1 as it continues down it divides into a upper one called the ilio Hypogastric and a lower one called the ilio inguinal. They supply the transverses of dominus and The internal oblique and we can see this nerve is supplying these two muscles The ilio hypogastric supplies the skin of the lower part of the abdomen But it does not go outside the abdomen Ilio inguinal continues and it supplies the skin of the thigh And it also supplies the skin of anterior scrotum and the labia majora where it is known as the anterior scrotal nerve Now the anterior labial nerve. The ilio inguinal component serves as the afferent limb of the cremaster reflex in male children Now we are showing the ilio inguinal and the ilio hypogastric nerve on the right side And this is the L1 and we can see it is ramifying Within the lower fibers of the internal oblique and the transverses of dominus So this is the distribution of the ilio inguinal ilio hypogastric that is L1 The next branch of the lumbar plexus that you can see on the left side is this which we have lifted up here This is the lateral femoral cutaneous nerve which comes from the posterior division of the lumbar plexus L2-3 If you watch carefully when I exert traction here we will see it is moving on the thigh So this is the continuation of the lateral femoral cutaneous nerve This lateral femoral cutaneous nerve it crosses the iliac fossa and it emerges into the thigh Under the ilio inguinal ligament close to its attachment to the anterior superior iliac spine And this is the place where it is coming And then it supplies the skin of the antrolateral aspect of the thigh here In this position where it is coming out from the under the ilio inguinal ligament It can get entrapped especially when the person gains weight And then it can produce numbness, tingling and peristhesia on the lateral aspect of the thigh And that condition is known as meralgia peristhetica So this is the lateral femoral cutaneous nerve on the left side Now we have picked up the lateral femoral cutaneous nerve on the right side And if you watch on the thigh we will notice that when I exert traction here The lateral femoral cutaneous nerve on the thigh is moving here So this is the LFC on the right side And as we mentioned it is passing under the ilio inguinal ligament close to its attachment to the anterior superior iliac spine And this is the place where we mentioned it can get entrapped The next nerve that we have picked up on the left side is this one here This is the operator nerve This is the anterior division of L2-3-4 And this operator nerve enters into the pelvis And it passes through the operator foremen And it comes out of the medial side of the thigh And it supplies all the adductor muscles on the medial side of the thigh As well as a little bit of the pectinus And it supplies the skin of the middle medial side of the thigh And we shall show you the continuation of the same operator nerve on the thigh We have lifted up the operator nerve on the medial side of the left thigh And we can see that it is coming out between the adductor magnus and the adductor brevis And then it runs between the adductor magnus and the adductor longus And it ramifies and supplies the muscles on the medial side of the thigh We are going to put an instrument to show the continuity of this operator nerve with the pelvis To come back where we had started This is the operator nerve on the thigh And we have put an instrument along the course of the operator nerve If you look on the inner side of the pelvis We can see that the tip of the instrument has come out through the operator foremen On to the left pelvis And if you were to look at the tip of the instrument, we notice the operator nerve And the operator vessels are also passing through the same foremen So this is the course taken by the operator nerve as it passes from the lumbar region Through the pelvis, through the operator foremen, on to the medial side of the thigh Now we have picked up the operator nerve on the right side This is the operator nerve and it is accompanied by the operator vessels And we can see that it is disappearing through this opening here This is the operator foremen on the right side And it goes to the right thigh So this is L234 anterior division The next nerve that we can see is the one which we have picked up here This is the femoral nerve This is the posterior division of L234 on the left side And when I exert traction here, we can see that it is moving on the thigh here And when I exert traction here, we can see it is moving here So this is the femoral nerve which passes under the inguinal ligament where my finger is passed And it comes to the thigh Immediately on entering the thigh, it divides into hundreds and thousands of branches Which supplies the muscles of the anterior compartment And we can see that here Additionally, it also gives a saphenous nerve, which is the longest cutaneous branch And it also gives the anterior cutaneous nerve of the thigh Which we can see here We have picked up the femoral nerve on the right side Femoral nerve comes out from under the sua spager lateral to it And when I exert traction here, we can see that it is moving on the right thigh here So this is the continuity of the right femoral nerve Which supplies the anterior muscles of the thigh The next nerve that I'm going to pick up is visible only on the right side And it runs in front of the sua spager muscle And that is this nerve here This is the genitofemoral nerve L12 The genitofemoral nerve runs in front of the sua spager And then it divides into a femoral branch and a genital branch Femoral branch supplies the skin of the upper thigh And the genital branch runs through the inguinal canal Along with the ilio-inguinal nerve And it supplies the cremaster muscle This genitofemoral nerve provides the efferent limb of the cremaster reflex In male children So therefore just to recap, ilio-inguinal nerve is the afferent limb of the cremaster reflex And the genitofemoral is the efferent limb of the cremaster reflex The genitofemoral nerve is not clearly visible on the left side The next nerve that we have picked up here is this one This is the lumbo-sacral trunk L45 The lumbo-sacral trunk does not come out of the abdomen Instead it goes from the abdomen, from the lumbar region It goes into the pelvis And there it merges with the sacral plexus S123 And it contributes to the formation of the sciatic nerve Therefore the root value of the sciatic nerve is L45S123 On the right side, this is the lumbo-sacral trunk that we can see here And this lumbo-sacral trunk also follows the same course as we mentioned on the left side So these are all the branches of the lumbar plexus that we have shown sequentially First on the left side and then on the right side with their respective clinical correlations Thank you very much for watching Dr. Sanjay Sanyal signing out If you have any questions or comments, please put them in the comment section below David O is the camera person Have a nice day