(5.01)

Now we’ll move on, to look at the vessels and nerves of the region. We’ll go from the knee, where we saw them last, to just below the ankle. We’ll start with the veins.

Here’s the leg with the skin removed. To expose the two major superficial veins, two strips of subcutaneous fat have also been removed. Here’s the short saphenous vein on the back, and the long saphenous vein on the front.

The long saphenous vein passes over the medial malleolus, which is here, and runs up the medial side of the leg. We’ve seen its more proximal course in the previous sections of this tape.

The short saphenous vein runs up between the calcaneal tendon and the lateral malleolus. It goes up the back of the leg, and passes through the deep fascia near the knee to join the popliteal vein.

To see some of the superficial veins in more detail, we’ll remove the subcutaneous fat from the back of the leg. The short saphenous vein, like the long saphenous vein, is joined by a number of superficial branches The saphenous veins are also joined by several perforating veins like this one, which bring blood from the muscle compartments that lie deep to the investing deep fascia.

In the last section we saw the principal deep vein of the leg, the popliteal vein. here it is again. With the tibial nerve behind it and the popliteal artery in front of it, it disappears between the two heads of gastrocnemius. In this section we won’t follow the deep veins any further, since their course is just the same as that of the corresponding arteries.

We’ll look at the arteries next. The three main arteries which supply the leg and ankle region are all branches of the popliteal artery. They’re the anterior tibial, the posterior tibial, and the peroneal. In the dissection that we’ll see, all the veins have been removed, to simplify the picture.

Here’s the popliteal artery, passing between the two heads of gastrocnemius. Its branches to gastrocnemius have been removed. To follow the popliteal artery, we’ll remove gastrocnemius. The popliteal artery runs down the back of the popliteus muscle, then passes through the fibrous arch in the origin of soleus. We’ll remove soleus.

At the lower border of the popliteus muscle, the popliteal atery gives off this major branch, the anterior tibial artery, which runs forwards. We’ll follow it in a minute. The popliteal artery then ends by dividing into the peroneal artery, and the posterior tibial artery. We’ll follow the posterior tibial artery first. It runs down the back of the leg, just behind the deep posterior muscles. It’s covered by the increasingly thick transverse intermuscular septum, which we’ll remove.

As it passes toward the medial side of the ankle, the posterior tibial artery lies just behind tibialis posterior. At the ankle, the artery passes through a tunnel beneath the flexor retinaculum, part of which has been removed here. Within its tunnel, the posterior tibial artery divides into the medial plantar, and lateral plantar arteries, which we’ll follow in the next section.

Next we’ll look at the peroneal artery. The peroneal artery passes laterally, and runs beneath a muscle that we’ll be looking at at in the next section, flexor hallucis longus. We’ll remove it. The peroneal artery runs down between the deep posterior muscles, close to the fibula, which is here. It gives off numerous branches to the surrounding muscles, and ends behind the lateral malleolus.

Lastly, we’ll look at the anterior tibial artery. Here’s where we saw the anterior tibial artery last, arising from the popliteal artery. It immediately passes forward through a gap in the interosseous membrane. We’ll go round to the front to follow it. Here it is emerging. The anterior tibial artery runs down the leg on the interosseous membrane, just lateral to tibialis anterior. The long toe extensors, which have been removed in this dissection, lie lateral to the artery. At the ankle, the anterior tibial artery passes beneath the extensor retinaculum. Here’s the artery emerging on the dorsum of the foot. Beyond this point it’s called the dorsalis pedis artery. We’ll follow it further in the next section.