Lumbar and Sacral Plexuses Flashcards
What spinal nerves contribute to the lumbar plexus
Ventral Rami of L1-L4
Which spinal nerves contribute to the sacral plexus
Ventral Rami of L4-S4
Which six named nerves form from the lumbar plexus?
Interested, In, Getting, Laid, On, Friday
Iliohypogastric, Ilioinguinal, genitofemoral, lateral cutaneous nerve of the thigh, obturator, femoral
Which nerve roots contribute to the iliohypogastric nerve?
L1 and contributions from T12
What does the iliohypogastric nerve innervate?
Motor: Internal oblique and transversus abdominis
Sensory: posterolateral skin in gluteal region
Which nerve roots contribute to the ilioinguinal nerve?
L1
What does the ilioinguinal nerve innervate?
Motor: Internal oblique and transversus abdominis
Sensory: Upper middle thigh
Men- anterior scrotum and root of penis
Women - skin over labia majora and mons pubis
Which nerve roots contribute to the genitofemoral nerve?
L1 and L2
What does the genitofemoral nerve innervate?
Genital branch: Cremasteric muscle (motor)
Men- anterior scrotum and root of penis
Women - skin over labia majora and mons pubis
Femoral branch: Skin on upper anterior thigh
Which nerve roots contribute to the lateral cutaneous nerve of the thigh?
L2 and L3
What does the lateral cutaneous nerve of the thigh innervate?
Sensory: Anterior and lateral thigh down to the knee
What is the clinical relevance of the lateral cutaneous nerve of the thigh?
Can become compressed by wearing tight clothing, loose sensation to the area it supplies.
Which nerve roots contribute to the Obturator nerve?
L2, L3,L4
What does the obturator nerve innervate?
Motor: Medial compartment of the thigh
Sensory: Skin on medial thigh
Which nerve roots contribute to the femoral nerve?
L2,L3,L4
Describe the anatomical course of the femoral nerve
Decends in the lumbar plexus, passes through psoas major, runs behind the inguinal ligament into the thigh and passes in the femoral sheath with the vein and artery through the femoral triangle.
What does the femoral nerve innervate?
Motor: Anterior compartment of the thigh, plus illiacus and pectineus
Sensory: Skin on anterior thigh and medial leg.
What are the major named branches of the Sacral plexus? (5 of them)
Some, Irritating, Sailors, Pestered, Polly
Superior gluteal Inferior gluteal Sciatic Posterior femoral cutaneous Pudendal
Which nerve roots conrtibute to the superior gluteal nerve?
L4, L5, S1
Through which foramen do all the named nerves of the sacral plexus leave the pelvis?
Greater Sciatic Foramen
What does the superior gluteal nerve innervate?
Motor: Gluteus medius and minimus and tensor fascia lata (TFL)
Which nerve roots conrtibute to the inferior gluteal nerve?
L5, S1, S2
What does the inferior gluteal nerve innervate?
Motor: Gluteus maximus
Which nerve roots contribute to the sciatic nerve?
L4,L5,S1,S2,S3
