1.3.2. The Sacral Plexus Flashcards
What is the Sacral Plexus?
A network of Nerve Fibers, which supplies the Skin and Musculature of the Pelvis and Lower Limb
Where is the Sacral Plexus located?
- It is located on the Surface of the Posterior Pelvic Wall
- Anterior to the Piriformis Muscle
What forms the Sacral Plexus?
- The Anterior Rami of the of Spinal Nerve S1
- The Anterior Rami of the of Spinal Nerve S2
- The Anterior Rami of the of Spinal Nerve S3
- The Anterior Rami of the of Spinal Nerve S4
(5. The Anterior Rami of the of Spinal Nerve L4 also contributes)
(6. The Anterior Rami of the of Spinal Nerve L5 also contributes)
How do the Spinal Nerves leave the Spinal Cord?
Via the Intervertebral Foramina of the Vertebral Column
What happens to the Nerves, after they leave the Spinal Cord?
They divide into Anterior and Posterior Fibers (or Rami)
What happens to the Anterior Rami of S1-S4?
They intertwine (The Sacral Plexus) and divide into several cords
- Which Lumbar Roots join the Anterior Rami of S1-S4?
- What do they combine to form?
- a) L4
- b) L5
- Lumbosacral Trunk
Where does the Lumbosacral Trunk travel?
Into the Pelvis
What does the Lumbosacral Trunk join?
The Sacral Plexus
What do the Cords which leave the Sacral Plexus goes on to form?
Major Peripheral Nerves of the Sacral Plexus
What are the Major Peripheral Nerves of the Sacral Plexus?
- Superior Gluteal Nerve
- Inferior Gluteal Nerve
- Sciatic Nerve
- Posterior Femoral Cutaneous Nerve
- Pudendal Nerve
What are the 2 main destinations of the Major Peripheral Nerves of the Sacral Plexus?
- Leaving the Pelvis to the Gluteal Region
- Remaining in the Pelvis
Which Major Peripheral Nerves of the Sacral Plexus leave the Pelvis, to the Gluteal Region?
- Superior Gluteal Nerve
- Inferior Gluteal Nerve
- Sciatic Nerve
- Posterior Femoral Cutaneous Nerve
Which Major Peripheral Nerves of the Sacral Plexus remain in the Pelvis?
The Pudendal Nerve
How does the Superior Gluteal Nerve leave the Pelvis?
Via the Greater Sciatic Foramen
Where does the Superior Gluteal Nerve enter into the Gluteal Region, in relation to the Piriformis Muscle?
Superiorly
What accompanies the Superior Gluteal Nerve as it enters into the Gluteal Region?
- Superior Gluteal Artery
- Superior Gluteal Vein
What is the Segmental (or Nerve Root) Value of the Superior Gluteal Nerve?
- L4
- L5
- S1
What is the motor function of the Superior Gluteal Nerve?
- Innervation of the Gluteus Minimus Muscle
- Innervation of the Gluteus Medius Muscle
- Innervation of the Fascia Lata