Anatomical regions provide a precise way to describe specific areas of the human body, enabling clear communication in medicine and science. This systematic approach ensures accuracy when discussing location and associated structures. This article defines and locates the sural region, detailing its boundaries and key anatomical components.
Locating the Sural Region
The sural region refers to the posterior portion of the lower leg, commonly known as the calf. It extends from just below the knee down to the ankle. This area is distinct from the anterior (front) or lateral (side) compartments of the lower leg.
The upper boundary of the sural region is the popliteal fossa, the hollow area behind the knee joint. Its lower boundary extends to the ankle, specifically encompassing the area above the heel. This region is delineated by prominent calf muscles that define its overall shape.
Key Structures Within the Sural Region
The sural region contains several important anatomical structures, including major muscles, nerves, and blood vessels. The gastrocnemius and soleus are the most prominent muscles, forming the bulk of the calf. The superficial gastrocnemius, with two heads, originates from the femur, while the broad, flat soleus lies deep to it. A smaller muscle, the plantaris, is often nestled between them. These muscles collectively attach to the heel bone via the Achilles tendon.
The sural nerve is a significant nerve in this region, formed by the union of two smaller sensory nerves: the medial sural cutaneous nerve (a branch of the tibial nerve) and the lateral sural cutaneous nerve (a branch of the common fibular nerve). This nerve is primarily sensory, providing sensation to the skin on the posterolateral lower leg, ankle, and side of the foot. It typically courses alongside the small saphenous vein. The tibial nerve also innervates most of the calf muscles.
Blood supply to the sural region comes primarily from the sural arteries, branches of the popliteal artery located behind the knee joint. These arteries, typically including medial and lateral sural arteries, supply blood to the gastrocnemius, soleus, and plantaris muscles. The sural veins, including medial and lateral sural veins, are part of the deep venous system and drain blood from the gastrocnemius muscle, often accompanying the sural arteries and nerve.