Sensory supply of first web space of foot is by:
**Core Concept**
The sensory supply of the foot is provided by the medial and lateral plantar nerves, which are branches of the posterior tibial nerve. These nerves originate from the lumbar and sacral nerve roots, specifically L4-S3, and are responsible for transmitting sensory information from the foot to the central nervous system.
**Why the Correct Answer is Right**
The first web space of the foot is supplied by the medial plantar nerve, which is a branch of the posterior tibial nerve. The medial plantar nerve provides sensory innervation to the medial three and a half toes, including the first web space. This is due to the specific branching pattern of the posterior tibial nerve, which divides into the medial and lateral plantar nerves. The medial plantar nerve then further divides into digital nerves that supply the individual toes. The correct answer is **Option C:** Medial plantar nerve.
**Why Each Wrong Option is Incorrect**
* **Option A:** The lateral plantar nerve supplies the lateral four and a half toes, not the first web space.
* **Option B:** The sural nerve, a branch of the common peroneal nerve, supplies the lateral aspect of the foot, not the first web space.
* **Option D:** The saphenous nerve, a branch of the femoral nerve, supplies the medial aspect of the leg and foot, but not the first web space.
**Clinical Pearl / High-Yield Fact**
The medial and lateral plantar nerves can be tested for by performing a plantar nerve stretch test, which involves dorsiflexion of the foot and inversion of the ankle. This can help diagnose plantar nerve entrapment or compression.
**Correct Answer: C. Medial plantar nerve.**