Nervus saphenus brevis or externus, also known as the short saphenous nerve or external saphenous nerve, is a peripheral nerve that plays a crucial role in the sensory innervation of the lower limb. It arises from the sciatic nerve, a major nerve branching from the lower back, and descends along the back of the thigh.
The nervus saphenus brevis primarily supplies sensation to the lateral, or outer, side of the leg and foot. It specifically innervates the skin over the calf, the back of the ankle, and the outer side of the foot, as well as the lateral fifth toe. This nerve also conveys sensory information from the sural nerve, a tributary nerve that receives sensations from the calf region.
Despite its smaller size compared to other major nerves in the lower limb, the nervus saphenus brevis has clinical significance. It can be involved in certain medical conditions, such as nerve entrapment or injury, resulting in symptoms like pain, numbness, or tingling in the areas it innervates. Knowledge of its anatomy, function, and distribution is crucial in diagnosing and treating such conditions.
In summary, the nervus saphenus brevis or externus is a peripheral nerve originating from the sciatic nerve. It provides sensory innervation to the lateral aspect of the leg and foot, including the calf, ankle, lateral fifth toe, and receives sensory input from the sural nerve.
