(2.25)
Now let’s look at the nerves. In the last section we looked at three major nerves - the obturator, the femoral, and the sciatic. We’ll follow the sciatic nerve in a minute. The obturator nerve and the femoral nerve we don’t need to follow any further, except to remind ourselves of the muscles that they supply.
As we’ve seen before, the obturator nerve supplies obturator externus, adductor brevis, and longus, and the anterior part of adductor magnus. The femoral nerve supplies iliacus, pectineus, all four heads of quadriceps, and sartorius.
The obturator and femoral nerves also have sensory branches, some of whch go below the knee. We’ll leave these out. We’ll go on now to look at the sciatic nerve. We saw the sciatic nerve a minute ago, with the hamstring muscles absent. To see the whole picture, we’ll add the hamstring muscles.
Here are semimembranosus and semitendinosus, here’s biceps femoris. Here are the two heads of gastrocnemius. The space that’s bounded by these muscles is called the popliteal fossa. As we saw in the previous section, the sciatic nerve passes deep to biceps femoris. Here it is emerging. Here are the popliteal vessels, coming in beneath the “semi “ muscles, and passing deep to the nerve. Above the knee the sciatic nerve divides into two major nerves - the tibial nerve, and the common peroneal nerve.
The tibial nerve runs downward in the midline, and passes between the two heads of gastrocnemius, along with the popliteal vessels. The common peroneal nerve diverges laterally, running just behind the tendon of biceps femoris.
It passes around the neck of the fibula, here’s the fibula, and passes into this muscle, peroneus longus. We’ll follow the further course of both these nerves in the next section.
Of the muscles that we’ve seen ...
(2.25)
Now let’s look at the nerves. In the last section we looked at three major nerves - the obturator, the femoral, and the sciatic. We’ll follow the sciatic nerve in a minute. The obturator nerve and the femoral nerve we don’t need to follow any further, except to remind ourselves of the muscles that they supply.
As we’ve seen before, the obturator nerve supplies obturator externus, adductor brevis, and longus, and the anterior part of adductor magnus. The femoral nerve supplies iliacus, pectineus, all four heads of quadriceps, and sartorius.
The obturator and femoral nerves also have sensory branches, some of whch go below the knee. We’ll leave these out. We’ll go on now to look at the sciatic nerve. We saw the sciatic nerve a minute ago, with the hamstring muscles absent. To see the whole picture, we’ll add the hamstring muscles.
Here are semimembranosus and semitendinosus, here’s biceps femoris. Here are the two heads of gastrocnemius. The space that’s bounded by these muscles is called the popliteal fossa. As we saw in the previous section, the sciatic nerve passes deep to biceps femoris. Here it is emerging. Here are the popliteal vessels, coming in beneath the “semi “ muscles, and passing deep to the nerve. Above the knee the sciatic nerve divides into two major nerves - the tibial nerve, and the common peroneal nerve.
The tibial nerve runs downward in the midline, and passes between the two heads of gastrocnemius, along with the popliteal vessels. The common peroneal nerve diverges laterally, running just behind the tendon of biceps femoris.
It passes around the neck of the fibula, here’s the fibula, and passes into this muscle, peroneus longus. We’ll follow the further course of both these nerves in the next section.
Of the muscles that we’ve seen in this section, the tibial nerve supplies popliteus, gastrocnemius, and plantaris.