 This is going to be a demonstration of some special structures which extend from the thigh to the knee and go from the leg to the thigh, crossing the knee. So let's start off with this structure that we have picked up here. This is the long subvenous vein. It starts as the medial marginal vein of the foot. It runs on the middle side of the leg in front of the medial malleolus, it continues up and then it goes just behind the medial corner of the fever, approximately one palm width behind the medial side of the knee and then it runs up on the medial side of the thigh and then it finally terminates in the femoral vein through the subvenous opening. Accompanying this long subvenous vein, we have this nerve here. This is the subvenous nerve. The subvenous nerve is the longest cutaneous branch of the femoral nerve and it runs with the long subvenous vein. So let's trace the subvenous nerve. This is the subvenous nerve which is coming from the femoral nerve and we can see the subvenous nerve is entering, going under the sartorius, it enters this adductor canal. When it pierces through the adductor canal, first it gives a branch which runs outside and it supplies the skin of the medial side. And then the main subvenous nerve then continues and it goes under the sartorius and we can see the other side of the nerve here. This is the nerve. It continues and then it runs with the long subvenous. When I lift up the sartorius insertion, we can see that it is split and just running under the sartorius insertion is this subvenous nerve which runs just under and partly through the insertion of the sartorius and then comes out distally and accompanies the subvenous vein. It also gives multiple cutaneous branches which we can see here which also accompany the subvenous vein but they become superficial here. This is a major supplier, cutaneous supplier of the medial side of the thigh, medial side of the knee, medial side of the leg, anterior medial and posterior medial and little bit of the medial side of the foot. So long subvenous vein is a useful way for various sections of any puncture and harvesting for coronary artery bypass in which case we are likely to inadvertently injure the accompanying subvenous nerve. So this is one structure which I want to show. Now let's show another composite structure which extends from the thigh to the knee. I would draw your attention to this structure which I have lifted up here, here and here. If you look closely here, this is like the foot of a goose. This is known as the pest and sirenas for the goose food insertion. It is formed by the composite insertion of three muscles, one each from the anterior medial and posterior compartment. So let's see which are the muscles and let's trace them. From the anterior compartment we have this muscle here. This is the sartorius muscle and we can trace the sartorius and I am tracing the sartorius and we can see that the sartorius as it is coming it turns below the medial condensate of the tibia and this gets inserted here. Incidentally if you want to look inside the insertion of the sartorius you'll find that it is split into two layers and we can see the two layers here and between the two layers is the subvenous nerve. So this is one component of the goose foot insertion. Now let's take the next muscle. That is the muscle of the medial compartment, this one which I have lifted up. This is the gracilis. And we can see that the tendon of insertion of the gracilis is very thin, narrow and delicate and that is why it is called a gracilis muscle. The gracilis muscle also goes around and my finger is tracing it and it comes here and I have lifted it up here and it gets inserted here. So that's the second insertion of the pest and sirenas namely the gracilis. Now the third insertion is this one which we have lifted up here. This is the semitendinosis. The semitendinosis muscle is a muscle of the posterior compartment. So therefore we cannot see the full muscle here but we will trace the semitendinosis tendon with my finger and when I trace it, it is going behind the knee and now it is in the posterior compartment. So this is the semitendinosis. So these three together constitute the pest and sirenas like the foot of a goose, the sartorius which is a flat insertion, the gracilis which is a tendinous cord-like insertion and the semitendinosis which is also a tendinous cord-like insertion. This is a still shot from another section showing my hand holding up the three tendons of the pest and sirenas. Triple insertion of the three muscles, one each from the anterior middle posterior compartment. If you notice that each of these muscles are taking their origin from the pelvis above the hip joint. Sartorius is taking origin from the anterior lexpine, gracilis is taking origin from the pubic bone and the semitendinosis takes origin from the eschewed tuberosity, all of which cross the hip joint and now they are crossing the knee joint. So therefore each of these muscles are two joint muscles. They are acting on the hip and they are acting on the knee. On the medial side, these are the muscles. On the lateral side we have this strong aponeuritic structure. This is the iliotibial tract. The iliotibial tract provides attachment to two muscles. One muscle we can see here between my thumb and index finger, this is the tensor fascialata. And there's a bigger muscle from the posterior aspect of the gluteal region, which is the gluteus maximus. The superficial three-folds of the gluteus maximus gets attached inserted onto the iliotibial tract. The iliotibial tract is nothing but a very extremely thickened portion of the fascialata. And this iliotibial tract then continues down as the aponeurotic expansion of these two muscles and they get inserted onto the tubercula, on the anterolateral aspect of the tibia. And that is known as the anterolateral tubercula of Gerdi. These two muscles, the tensor fascialata and the gluteus maximus, these two are also two joint muscles insofar that their origin is from the pelvis. And the insertion is below the knee. So therefore the iliotibial tract on the right side and the pestanserinas, the triple insertion on the medial side, all these three plus two muscles, they are all two joint muscles. They're acting on the hip, they're acting on the knee. They stabilize the hip and the knee and they balance each other out, one from the medial side and one from the lateral side. So this is the functional implication of the pestanserinas on the medial side and the iliotibial tract on the other side with their respective muscles. The next point I wanted to mention is that between the iliotibial tract and this muscle, this is the castus lateralis, there is a bursa which has been removed in this region. That's called the gluteofamoral bursa. That is to prevent friction of the iliotibial tract against the castus lateralis. Similarly, there is a bursa between the pestanserinas, the three tendons of the pestanserinas and the medial aspect of the tibia. Part of that we can see here and that is known as the anterine bursa. So this anterine bursa prevents friction between the three tendons of the pestanserinas and the tibia. So these are some of the points which I wanted to mention about the superficial structures on the upper medial aspect of the tibia with reference to the pestanserinas and their functional significance. Thank you very much for watching. If you have any questions or comments, please put them in the comment section below. Dr. Sanjay Sanyal, signing out. Have a nice day.