 This is going to be a demonstration of the superficial structures on the back of the leg there's a prone cadaver There's the right side. We are narrating from the right side The camera person is also on the right side and my assistants are also on the right side So we have removed the fat and the superficial fascia from the back of the right leg of this cadaver Let's take a look at this nerve here This is the posterior femoral cutaneous nerve. This is the posterior nerve of the thigh This has got a very unique course and very unique origin. It starts by two sets of roots One is the posterior division ramei of S12 and anterior ramei of S23 The two of them unite to form the posterior cutaneous nerve of the thigh It runs with the sciatic nerve just under the pyriformis in the gluteal region and As it comes down it separates from the sciatic nerve and runs independently on the back of the thigh In the gluteal region the S23 anterior ramei component gives branch Which supplies the inferior gluteal nerve to the skin of the lower part of the butter and The rest of the posterior femoral cutaneous nerve as we can see it runs down on the back of the thigh just about the Pyriformis it pierces the deep fascia and becomes subcutaneous And it supplies the skin of the back of the Pyriformis up to a variable part of the leg and that is what we can see here Now we shall reflect this aside and we will show you yet another cutaneous nerve This is the nerve which I was referring to This is the sural nerve The sural nerve is formed again in a very unique way and for that we will go to the perpital fossa so this is the sciatic nerve here in this particular category the sciatic nerve is dividing rather low down and It is dividing it to a tbl division and a common fibular division So this sural nerve is formed by the unique way. We see this nerve here This is the medial sural cutaneous nerve It's a branch from the tbl division of sciatic nerve and We can see yet another branch coming from the common fibular This is the lateral sural cutaneous nerve The medial sural cutaneous nerve and the contribution from the lateral sural cutaneous nerve Unite to form the sural nerve itself and we can see the sural nerve forming here and the sural nerve then runs down And it supplies the skin of the posterior part of the calf the lower one third This cutaneous nerve is an important nerve from the surgical perspective It is used for nerve drafting for example to replace a Lost portion of the facial nerve after perotin surgery. So that brings me to the next point during surgery How do we recognize the sural nerve? So for that we use this as a reference We can see this vein here superficial vein This is the short subvenous vein The short subvenous vein runs with the sural nerve on the back of the calf and It runs up and it continues and we can see it here And it pierces the propitial fascia and it opens into the femoral vein and we can see the rest of the short subvenous vein here This short subvenous vein is used as a landmark to recognize the sural nerve Then we need the sural nerve for harvesting So that brings me to how's the short subvenous vein formed? It is formed by union of the planter vein is network of the foot And all these veins then converge on the lateral side of the foot and we can see them and it forms the lateral marginal vein And the lateral marginal vein then comes up as the short subvenous vein As it goes up we can see it is giving multiple communications We can see one communication here We can see another communication here and we can see another communication here. These are all the perforators These perforators they pierce through the deep fascia Which is the cruel fascia and they go into the deep veins of the calf blood flows from superficial to deep And if there's a perforator incompetence, we can rarely get varicosity of the short subvenous vein and that brings me to another point Accompanied the short subvenous vein Are the lymphatics from the sole of the foot and from the lateral marginal of the foot and any infection in this region? Will travel with the lymphatics with the short subvenous vein and they will drain first into the Popleatial lymph nodes and thereafter they will go to the femoral nodes So this is a point to be remembered about the distribution That brings me to yet another though, which is not located in the bushy aspect, but we can see it in this dissection We can see a superficial curve here This is the superficial fibular nerve The superficial fibular nerve after supplies the muscles of the lateral compartment. It pierces the deep fascia We can see it piercing here, and it runs on the antrolateral aspect of the leg as The superficial fibular cutaneous nerve and it supplies the skin here, and then it goes to the Dorsum of the foot so that's to get another one we can see So that is all that we wanted to show you in the superficial dissection on the back of the leg here in the next Dissection we shall show triceps today and the deeper structures. Thank you very much for watching Dr. Sanger signing out signing out if you have any questions or comments, please put them in the comment section below My MD1 students are my assistants. Have a nice day