Lumbosacral Plexus Flashcards
Which anterior rami make up the lumbosacral plexus?
L1 - L5; S1 - S4
Which spinal nerves make up the lumbar plexus?
Anterior rami of spinal nerves L1 - L4
Which muscles does the lumbar plexus innervate?
Muscles of anterior and medial thigh
What contributes to the sacral plexus?
Anterior rami of spinal nerves L4 - L5 and S1 - S4
Which muscles does the sacral plexus innervate?
Muscles of the gluteal region
Which plexus does the sciatic nerve originate from?
Sacral plexus
Which regions does the sciatic nerve innervate?
Posterior thigh, leg, foot
Which nerves exit through the greater sciatic foramen? Which regions do they innervate?
Gluteal nerves - Gluteal region
Sciatic nerve - Posterior thigh, leg, foot
Which nerve exits deep to the inguinal ligament? What region does it innervate?
Femoral nerve - Anterior thigh
Which nerve exits through the obturator foramen? Which region does it innervate?
Obturator nerve - Medial thigh
Which nerves arise from the lumbar plexus?
Iliohypogastric nerve Ilioinguinal nerve Genitofemoral nerve Lateral cutaneous nerve of thigh Femoral nerve Obturator nerve
Which anterior ramus contributes to the iliohypogastric nerve?
L1
Which anterior ramus contributes to the ilioinguinal nerve?
L1
Which anterior rami contribute to the genitofemoral nerve?
L1 - L2
Which anterior rami contribute to the lateral cutaneous nerve of the thigh?
L2 - L3
Which anterior rami contribute to the femoral nerve?
L2 - L4
Which anterior rami contribute to the obturator nerve?
L2 - L4
What is the lumbosacral trunk? Where does it travel?
Anterior rami of L4 - L5 that forms sacral plexus with S1 - S4 anterior rami
Descends into pelvis
What does the iliohypogastric nerve innervate?
Abdominal muscles
Skin overlying iliac crest
Hypogastric region
Which muscle is a landmark for finding both the iliohypogastric and ilioinguinal nerves?
Quadratus lumborum
Which regions does the ilioinguinal nerve innervate?
Abdominal muscles
Skin of genital region
Skin of medial thigh region
Where does the ilioinguinal nerve typically lie in relation to the iliohypogastric nerve?
Inferiorly
Where do the iliohypogastric and ilioinguinal nerves exit?
They disappear into the muscles of the anterolateral abdominal wall
Where is the genitofemoral nerve found?
It appears on anterior aspect of psoas major
What does the femoral branch of the genitofemoral nerve innervate?
Skin on anterior surface of thigh
What does the genital branch of the genitofemoral nerve innervate?
Cremaster muscle
Skin of genitals
Where does the genital branch of the genitofemoral nerve lie in relation to the femoral branch?
Medially
What does the lateral cutaneous nerve of thigh innervate?
Skin on anterolateral surface of thigh
Over which muscle does the lateral cutaneous nerve of thigh travel?
Iliacus
Where does the lateral cutaneous nerve of thigh exit the pelvis?
Medial to the ASIS, deep to the inguinal ligament
What does the femoral nerve innervate?
Iliacus
Anterior thigh
Where is the femoral nerve found?
Lateral to psoas major
What does the obturator nerve innervate?
Medial thigh
Where does the femoral nerve exit the pelvis?
Deep to inguinal ligament
Where does the obturator nerve exit the pelvis?
Obturator foramen
Where is the obturator nerve found?
Medial to psoas major
