Sciatic Nerve Anatomy and Function Quiz

### Sciatic Nerve Anatomy & Function

• The sciatic nerve is the largest nerve in the body.
• It originates from the lumbosacral plexus, specifically from the L4-S3 nerve roots.
• It passes below the piriformis muscle in the gluteal region.
• The tibial nerve arises from the posterior division of the sciatic nerve.
• Injury to the sciatic nerve can lead to weakness, numbness, and pain in the leg and foot.
• Sciatica is a condition characterized by pain radiating along the path of the sciatic nerve.

Muscles Supplied by the Sciatic Nerve

• The muscular branches of the sciatic nerve supply the hamstring muscles, adductor magnus, and short head of biceps femoris.

### Tibial Nerve

• The tibial nerve originates from the posterior division of the sciatic nerve.
• It supplies sensory innervation to the sole of the foot.

Sciatica Causes & Effects

• Sciatica is commonly caused by compression of the sciatic nerve due to conditions like herniated disc, spinal stenosis, or muscle strain.
• Injury to the sciatic nerve below the knee results in sensory loss in the sole of the foot.
• The sciatic nerve terminates by dividing into the tibial and common peroneal nerves.

### Gluteal Region Injections

• Intramuscular injections in the gluteal region should be given only in the upper lateral quadrant to avoid damaging the sciatic nerve.

Muscles of the Hip

• The piriformis muscle is supplied by the nerve to piriformis, which is a branch of the sacral plexus.
• Obturator internus muscle is supplied by the nerve to obturator internus.
• The quadratus femoris muscle is supplied by the nerve to quadratus femoris.
• The piriformis muscle is not one of the six lateral rotators of the hip joint.
• The obturator internus muscle originates from the inner surface of the obturator membrane.
• The gluteus medius muscle has its insertion on the tip of the greater trochanter.