 So this is the dissection of the gluteal region, this muscle that we see in front of us, this is the gluteus maximus, it's the largest muscle of the gluteal region in the superficial compartment. So it takes origin from the coccyx of the sacrum and from the ilium behind the superior posterior gluteal type and all the fibers they converge. Three-fourths of the fibers get inserted onto this tough structure that we see here. This is the iliotibia tract. Iliotibia tract is the poneuronic expansion of the insertion of the three-fourths of the gluteal muscles, the gluteus maximus and this goes down and gets inserted onto the tibia in a tubule called the adduilateral tubule of the gyr. The deep one-fourth of the gluteus maximus, which we can see here, gets inserted onto a tubule on the posterior surface of the femur or the gluteal tuberosity. So this is the origin and the insertion of the gluteus maximus. The nerve supply is the inferior gluteal nerve, which I should show you just now. The most important action of the gluteus maximus is extension of the hip and lateral rotation by virtue of its directional fibers and excretion. Now we will reflect the gluteus maximus but before that I need to say one more point. The gluteus maximus is partly a posterior muscle and partly an active muscle because it has got both type 1 and type 2 fibers. So it is responsible for sitting up, standing, climbing stairs apart from its other actions. Now I have split the gluteus maximus here and I am reflecting it. It was receiving numerous blood vessels, all of which were coming and all of which have been cut and we can see this is a branch from the inferior gluteal nerve which is supplying the gluteus maximus. Under the gluteus maximus, between the gluteus maximus and the ischial tuberosity there was a bursa and we can see the remnant of the bursa. This is the ischial bursa. In normal circumstances there is also a bursa between the gluteus maximus and the greater bursa. Finally there is also a bursa between the and that is known as the gluteus femoral bursa. These are the three most important bursa. Now we have reflected the gluteus maximus of the nerve but I am going to show you the nerve just a little later. The next muscle that we see in front of us is this one. This is the gluteus medius. This takes attachment from the posterior between the posterior and the anterior gluteal line of the ilium on the outer surface and the fibers almost descend on vertically as you can see here and they get inserted onto the greater trochanter. So this vertical descent of the fibers is very significant. This acts as a stabilizer of the pelvis especially when standing on one leg. And more importantly when bursa stands on one leg the opposite side pelvis wants to sag now. So therefore when these fibers contract they keep the pelvis stable and stable. So this is a very important action of the gluteus medius. The important action of the gluteus medius is abduction and medial rotation of the hip. Now we have cut open the gluteus medius here also and I am going to reflect. So this is the gluteus medius. I will show you the nerve supply just now. And once we reflect the gluteus medius we can see here another muscle on the left side and that muscle that we see here that is the gluteus minimus. The gluteus minimus also takes origin from the outer surface of the ilium between the anterior and inferior gluteal lines and the fibers also descend down almost vertically and they also get inserted onto the greater trochanter deep to the gluteus medius and they also have the same action as the gluteus medius namely abduction and medial rotation of the hip. But it is less important than the gluteus medius. And finally we have in the superficial groove a muscle which is between my finger here within the iliotibial tract and a little bit of that is visible here. Can you bring the camera? This is the tenserfation which takes origin from the outer surface of the iliac crest and it is a triangular shaped muscle something like this and the fibers then converge onto the iliotibial tract and little bit of the iliotibial tract have removed to show the muscle here and then the fibers. So if we were to look from behind we will see that the gluteus maximus posteriori and laterally the tenserfation both of them get inserted onto the iliotibial tract and the iliotibial tract is the aponeurotic expansion which goes up to the tube of the tibial. The iliotibial there is a feature that also has the same action in the abduction and medial rotation of the hip. And it is also supplied by the superior gluteus nerve just like the gluteus medius and the gluteus minimus. I will show the nerve just a little bit. So gluteus maximus has been reflected gluteus medius has been reflected and this is the gluteus minimus. So these are the superficial gluteus. Now let's take a look at the deep gluteus muscles. To understand the deep gluteus muscles let's start the first one here. This muscle that we see here in front of us is a pear shaped muscle. This is the biophonist and I have lifted up the biophonist. This is the biophonist and if I put my finger inside the, my finger is going inside the pelvis. It has gone inside the pelvis because the biophonist takes origin from the inner surface of the sacrum and it comes out. And it is coming out to this opening here where my finger is gone in. This is the greater shattered pyromania. So it comes out through the greater shattered pyromania and when it comes out it divides the greater shattered pyromania into a suprapyriform compartment and then the fibres get inserted onto the narrow tendon to the tip of the greater pyromania. So this is the pyriformis. The next muscle of the deep gluteus. Let's go straight down. This is the sciatic nerve which I'll describe just now that we retract the sciatic nerve. Can somebody hold the sciatic nerve for me on that side? Somebody who is wearing sciatic nerve is. You can use this instrument to track between the folds. We see this muscle here in the sacrum. This is the quadratus femoris. The quadratus femoris is the lowest of the deep gluteus muscles. It takes origin from the Istio tuberosity and it's a quadrangular shaped muscle that's why we call it the quadratus femoris and it gets inserted onto the quadrate tubercle on the posterior surface of the femur. That's why it's called the quadratus femoris. I'll tell you the nerve supply just now and the actions just now because they're all together. If we look above the quadratus femoris we see yet one more muscle here. This is the inferior gemulus. This muscle. It's a very small and a very friable muscle which takes attachment also from the Istio tuberosity and it goes and gets inserted and above that we see yet one more muscle. This one. This is the superior gemulus which takes attachment from the Istio spine and gets inserted. The superior gemulus and the inferior gemulus both of them get inserted onto this tendon that I have picked up here. This tendon. This is the operator internus tendon. So let's take a look at the operator internus muscle. For that I will draw your attention to this surface. This is a region called the Istio anal muscle and my finger is on the operator internus muscle. This is the operator internus muscle. The operator internus muscle is on the inner surface of the femoris and on the inner surface of the operator membrane. So if you look at my finger, the attachment of the operator internus is in this plane. The tendon of the operator internus it makes a 90 degrees bend in this direction. So this is the axis of the tendon and this is the axis of the muscle. Then you see the tendon is making a 90 degrees bend and the tendon then goes through this passage where my instrument is going and this is the lesser shining forever. So the operator internus muscle takes origin from inside the pelvis and the tendon makes a 90 degrees bend around the Istio spine and it then travels like this and in the region of this of the Istio spine there is a bursa or the operator internus bursa because there is friction between the tendon and the Istio spine and this is the axis. Muscle tendon 90 degrees bend around the Istio spine which is just under my next finger and this is that same operator internus tendon which I mentioned just now. This white structure and this gets inserted all through the inner surface of the greater trochanter called the trochanteric bursa. The action of all these deep muscles piriformis superior gemulus operator internus inferior gemulus quadratus femoris action is lateral rotation of the femur lateral rotation of the hip joint. The piriformis is supplied by the nerve to piriformis which comes out from inside the pelvis therefore we cannot see it in this dissection. The superior gemulus and the operator internus they receive the nerve supply from the same nerve namely the nerve to operator internus. The inferior gemulus and the quadratus femoris receive the nerve supply from same namely the nerve to quadratus femoris. All these nerves are coming out from inside the pelvis from the sciatic nerve therefore we cannot see them here. So, this is about the deep group of muscles.