Cross section of the thigh/upper leg showing the different fascia in different colors
On the human body, the limbs can be divided into segments, such as the arm and the forearm of the upper limb, and the thigh and the leg of the lower limb. If these segments are cut transversely, it is apparent that they are divided into multiple sections. These are called fascial compartments, and are formed by tough connective tissue septa. These compartments usually have a separate nerve and blood supply to their neighbours. The muscles in each compartment will often all be supplied by the same nerve.
The thigh is usually divided into three compartments, each supplied by a specific nerve: