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Sciatic nerve

Nervus ischiadicus

The largest and longest nerve in the body, the sciatic nerve supplies motor innervation to the posterior thigh and every muscle below the knee, and sensation to the lateral leg, the foot, and part of the posterior thigh. Arising from the L4 to S3 roots of the sacral plexus, it leaves the pelvis through the greater sciatic foramen below the piriformis muscle, descends through the posterior thigh, and usually divides into the tibial and common peroneal nerves at the popliteal fossa. Irritation of the nerve, often from a herniated disc, produces sciatica, a pain that radiates down the back of the leg. Piriformis syndrome compresses it in the buttock, misplaced gluteal injections can injure it, and a complete lesion abolishes all movement below the knee.

Formed from the L4-S3 nerve roots of the sacral plexus. It exits the pelvis through the greater sciatic foramen below the piriformis muscle. It descends through the posterior thigh, dividing into the tibial and common peroneal (fibular) nerves, usually at the popliteal fossa.

On this page
प्रकार Nerve
शरीर तंत्र Nervous
शरीर क्षेत्र Hip
मूल संरचना nerve
लैटिन नाम Nervus ischiadicus
FMA ID 19034

कार्य

The largest and longest nerve in the body, providing motor innervation to the posterior thigh and all muscles below the knee. Provides sensory innervation to the lateral leg, foot, and parts of the posterior thigh.

नैदानिक महत्व

Sciatica (sciatic nerve irritation, often from disc herniation) causes radiating pain down the posterior leg. Piriformis syndrome compresses the nerve in the buttock. Improper gluteal injections can damage the nerve. Complete sciatic nerve injury causes loss of all movement below the knee.

Frequently Asked Questions

What does the sciatic nerve do?

The sciatic nerve is the largest and longest nerve in the human body. It provides motor innervation to most muscles of the posterior thigh and all muscles of the lower leg and foot. It also carries sensory information from the skin of the lower leg, foot, and part of the thigh back to the spinal cord.

Where is the sciatic nerve located?

The sciatic nerve forms from nerve roots L4 through S3 in the sacral plexus. It exits the pelvis through the greater sciatic foramen, typically below the piriformis muscle, and runs deep in the posterior thigh between the hamstring muscles. At the popliteal fossa behind the knee, it divides into the tibial nerve and common fibular nerve.

What causes sciatica?

Sciatica refers to pain radiating along the path of the sciatic nerve, typically from the lower back through the buttock and down the leg. The most common cause is a herniated lumbar disc compressing a nerve root (most often L4, L5, or S1). Other causes include spinal stenosis, piriformis syndrome, and rarely, tumors or injuries along the nerve's course.

References

  1. Foundational Model of Anatomy — FMA:19034 Reference anatomy ontology (University of Washington)
  2. UBERON — UBERON:0001322 Cross-species anatomy ontology (EMBL-EBI Ontology Lookup Service)
  3. Wikidata — Q307869 Structured knowledge base cross-reference
  4. Wikipedia — Sciatic nerve Encyclopedia article (verified cross-reference)

चिकित्सा अस्वीकरण

यह सामग्री केवल शैक्षिक और सूचनात्मक उद्देश्यों के लिए है। इसे पेशेवर चिकित्सा सलाह, निदान या उपचार के विकल्प के रूप में नहीं माना जाना चाहिए। किसी चिकित्सा स्थिति के बारे में आपके किसी भी प्रश्न के लिए हमेशा अपने चिकित्सक या अन्य योग्य स्वास्थ्य प्रदाता से सलाह लें। इस वेबसाइट पर पढ़ी गई किसी बात के कारण कभी भी पेशेवर चिकित्सा सलाह को नजरअंदाज न करें या इसे लेने में देरी न करें।

Educational Disclaimer

This content is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for medical decisions.

Data sources: Terminologia Anatomica, Foundational Model of Anatomy, Wikidata.