Lumbar & Sacral Plexus Flashcards
1
Q
What is a plexus?
A
- Network of nerves or vessels in the body that have a web-like formation
- Formed by anterior rami of nerve roots
2
Q
What is a nerve root?
A
- Paired branches that leave the spinal cord at each vertebral segment
- Exit the spinal column through the intervertebral foramen
- Nerve roots are mixed nerves comprised of efferent (motor) fibres & Afferent (sensory) fibres
3
Q
What is the Lumbar Plexus?
A
- a An entire plexus comprised of nerve roots L1-L4 that supply the skin and musculature of the lower limb
4
Q
What are the major peripheral motor nerves of the lumbar plexus?
A
- femoral nerve
- obturator nerve
5
Q
What 7 muscles are innervated by the femoral nerve?
A
- Rectus femoris, Vastus lateralis, medialis, intermedialis
- iliacus
- Sartorius
- pectineus
6
Q
What 5 muscles are innervated by the obturator nerve?
A
- adductor longus & brevis
- adductor Magnus (partial)
- gracilis
- obturator externus
7
Q
What is the Sacral Plexus?
A
- nerve roots of L5-S3 supplies the skin and muscles of the pelvis and lower limb
- located on the surface of the posterior pelvic wall
8
Q
What are the major peripheral motor nerves of the sacral plexus?
A
- superior gluteal nerve (L4-S1)
- inferior gluteal nerve (L5-S2)
- nerve to piriformis (L5-S2)
9
Q
What are the 3 muscles innervated by the superior gluteal nerve?
A
- gluteus medius
- gluteus minimus
- tensor fascia latae
10
Q
What muscle is innervated by the inferior gluteal nerve?
A
- gluteus Maximus
11
Q
what muscle is innervated by the nerve to Piriformis?
A
- piriformis
12
Q
What is the sciatic nerve?
A
- the thickest nerve in the body apart of the large (hamstring) portion of the adductor Magnus
- Two cords bound together, which split in the popliteal fossa & go separate ways:
- tibial branch & common peroneal branch
13
Q
What is the tibial branch of the sciatic nerve?
A
- Innervates the muscles of the posterior compartment of the lower leg
14
Q
What is common Peroneal branch of the sciatic nerve?
A
- divides into 2 at the head of the fibula
- superficial branch - runs in and supplies the muscles of the lateral compartment of the leg
- deep branch - It supplies all of the muscles of the anterior compartment as well as providing a cutaneous supply to the area between the 1st and 2nd toes
15
Q
What is the fibular nerve?
A
- its nerve roots run from L4-S2
- it follows the medial border of the biceps femoris, running in a lateral and inferior direction, over the lateral head of the gastrocnemius
- Innervates the short head of the biceps femoris directly
