Anatomy Bones and Muscles · MU Pleven

165. Sacral plexus. Sciatic nerve. Tibial nerve.

Covers the sacral plexus, listing its main nerve branches with their root levels and the region each supplies, then moves to the sciatic nerve: its origin, the course through the pelvis and posterior thigh, and where it divides. Branches are set out for the tibial and common fibular nerves, with their root levels, muscles and sensory areas, including a note on the sural nerve's formation.

Inside: 4 sections · 4 labelled pictures · 1 table · 20 flashcards · 2 min

Topic 164 of 236 in the MU Pleven syllabus for Anatomy Bones and Muscles (Medicine, Year 2). The free AceMed note covers it in 4 sections, about 229 words (2 min of reading), with 20 flashcards.

In this note

  1. SACRAL PLEXUS
  2. SCIATIC NERVE (nerve of the lower limb)
  3. Course :
  4. Branches :

SACRAL PLEXUS

Sacral Plexus Serve In (ON) Pelvis

SCIATIC NERVE (nerve of the lower limb)

  • Origin : L4, L5, S1, S2,S3 ( sacral plexus)
  • The sciatic nerve is the largest nerve of the body.
  • The sciatic nerve plays a crucial role in providing motor & sensory innervation to the lower limb.

Add more info if you want ;)

Course :

  • Leaves the pelvis through the greater sciatic foramen below the piriformis
  • Course through posterior thigh.
  • Bifurcates into tibial and common fibular (peroneal)
  • * It can also be described as two individual nerves bundled together in the same connective tissue.
  • * In some individuals the sciatic n. can birfucates as soon as it leaves the pelvis
  • * Tibial n. → Medial sural cutaneus + common fibular n. → sural communicating br. → Sural nerve S: Skin of the post. surface of the leg.

Branches :

  • Tibial n. (L4-S3) : this branch continues down the post. leg, providing motor innervation to the post. compartment of the leg & foot.
  • ↳ It carries sensory information from the sole of the foot.
  • Common Fibular (Peroneal) nerve (L4-S2): This branch travels laterally around the knee & provides motor innervation to the muscles in the anterior & lateral compartments. of the leg.
  • ↳ It carries sensory information from the dorsum (top) of the foot & antolateral leg.
  • superficial
  • m: fibularis longus & brevis
  • S: skin of the dorsum of the foot.
  • Deep
  • S: Foot.
  • m:
  • lateral cutaneus n.

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