The Lumbosacral Plexus Flashcards
Lumbar plexus consists of
T12-L4
Sacral plexus consists of
L4-S4
Coccygeal plexus consists of
S4- Co1
Subcostal nerve is
T12
T12 includes cutaneous branches that supply
supply sensory innervation to anterior and lateral body wall and skin over hip
The cutaneous domain of T12 overlaps with
Iliohypogastic nerve
T12 innervates
Rectus abdominis
Pyramidalis
Iliohypogastic nerve is
T12-L1
Iliohypogastic nerve is closely related to
Ilioinguinal nerve
Iliohypogastic nerve provides sensory innervation to
Inguinal region and superiormost lateral thigh
Cutaneous domain of the iliohypogastic nerve overlaps with
Subcostal nerve
Iliohypogastic nerve innervates
Oblique muscles
Transversus abdominis
Ilioinguinal nerve is
T12-L1
Ilioinguinal nerve provides sensory innervation to
superiormost inner thigh, root of penis and upper scrotal skin (male)
mons pubis and labia majora (female)
Ilioinguinal nerve innervates
Internal oblique muscle
Transversus abdominis muscle
What are the main four nerves of the lumbosacral plexus
Femoral
Obturator
Tibial
Common fibular
Genitofemoral nerve consits of
L1-L2
Femoral branch of genitofemoral nerve exits
Pelvis though lacuna vasorum
Femoral branch of genitofemoral provides ___ innervation to ___
Sensory innervation ot upper part of femoral triangle
Genital branch of genitofemoral nerve travels through
Superficial inguinal ring with spermatic cord
Genital branch of genitofemoral nerve supplies ___ innervation to ___
Sensory innervation to lower scrotal skin
Genital branch of genitofemoral nerve innervates ___ in males
Innervates cremaster muscle in males
Genital branch of genitofemoral nerve ends in ___
Mons pubis
Labia majora in females
Lateral femoral cutaneous nerve consists of
L2-L3
Lateral femoral cutaneous exits ___ through ___
Exits pelvis at ASIS through the lacuna musculorum
Lateral femoral cutaneous supplies ___ innervation to ___
Sensory innervation to skin of lateral thigh
Has NO motor innervation
Obturator consists of
L2-L4
Obturator exits __ through__
Exits pelvis through obturator canal
Obutrator innervates ___
Adductor muscles of the thigh
Femoral nerve consists of
L2-L4
Anterior division of the femoral nerve supplies ___ innervation to ___
Sensory innervation to anterior thigh
Femoral nerve- anterior division innervates
Pectineus
Sartorius
Femoral nerve posterior division is also called
Saphenous nerve
Posterior division of femoral nerve (Saphenous nerve) supplies ___ innervation to __
Sensory innervation to anterior leg
Posterior division of femoral nerve (saphenous nerve) innervates
Quadriceps muscle
Superior gluteal nerve consists of
L4-S1
Superior gluteal nerve exits pelvis through
Suprapiniform foramen
Superior gluteal nerve innervates
Gluteus medius
Gluetus minimis
Tensor fasciae latae
Inferior gluteal nerve consits of
L5-S2
Inferior gluteal nerve exits pelvis through
Infrapiniform foramen
Inferior gluteal nerve innervates
Gluteus maximus
Tibial component of siatic nerve consits of
L4-S3
Tibial component of siatic nerve exits pelvis through
Infrapiriform foramen
Is the tibial component of the siatic nerve sensory, motor, or both?
Both
The common fibular component of siatic nerve is
L4-S2
Common fibular component exits pelvis through
Infrapiriform foramen
Is the common fibular component of the siatic nerve sensory, motor, or both?
Both
Posterior femoral cutaneous nerve consists of
S1-S3
Posterior femoral cutaneous nerve exits pelvis through
Infrapiriform foramen
Posterior femoral cutaneous nerve supply ___ innervation to ___
Sensory innervation to posterior thigh and popliteal fossa
Inferior cluneal branch of the posterior femoral cutaneous nerve supplies
Inferior buttock
Inferior perineal branch of the posterior femoral cutaneous nerve supplies
Perineum
Is the posterior femoral cutaneous nerve motor, sensory, or both?
Neither
Pudendal nerve consists of
S2-S4
How does the pudendal nerve travel?
exits pelvis through infrapiriform foramen
Crosses superficial to ischial spine and sacrospinous ligament
Enters ischioanal fossa through lesser sciatic foramen
Coccygeal plexus contains
S4-S5
Anococcygeal nerve contains
S4-S5
Coccygeal nerve contains
S5
The ___ divides the greater sciatic foramen into ___ and ___
Piriformis muscle into
Suprapiriform foramen and infrapiriform foramen
Generally speaking, structures that pass into the perineum or lower extermity can enter or exit the pelvis by 1 of 4 routes:
Through the pelvic outlet
Over the rim of the pelvis
Through one of the paired foramina defined by both bone and soft tissue
Through the paired sacral foramina
What exits through the pelvic outlet?
Digestive, urinary, and most reproductive organs
What exits over the rim of the pelvis and inguinal ligament?
A few nerves
Spermatic cord
What exits through one of the paired foramina?
Arteries
Veins
Lymphatics
Most nerves
What exits through the paired sacral foramina?
Dorsal rami of sacral spinal nerves
Lateral sacral artery branches
What nerves exit through the superior rim of the pelvis and inguinal ligament?
Subcostal nerve
Iliohypogastic nerve
What nerve exits through the lacuna musculorum?
Lateral femoral cutaneous nerve
Femoral nerve
What nerve exits through the lacuna vasorum?
Femoral branch of genitofemoral nerve
What nerve exits through the ilioinguinal canal?
Ilioinguinal nerve
Genital branch of genitofemoral nerve
What nerve exits through the obturator canal?
Obturator nerve
What nerve exits through the suprapiriform foramen?
Superior gluteal nerve
What nerves exits through the infrapiriform foramen?
Inferior gluteal nerve
Sciatic nerve
Posterior femoral cutaneous nerve
Pudendal nerve
What nerve enters through the lesser sciatic foramen?
Pudendal nerve (entering perineum)
What big nerves are cranial and part of the lumbar plexus
Femoral nerve (and nerves to the iliacus and psoas)
Obturator nerve
What big nerves are part of the sacral plexus?
Common fibular nerve (and gluteal nerves)
Tibial nerve (and nerves to lateral rotators
Standing upright rotated the femur ___ through __ degrees and the body axis (and pelvis) ___ through __ degrees
Femur rotates 90 degrees ventrally
Body axis/pelvis dorsally through 90 degrees
Combined result of rotation of femur and pelvis is that
Innervation domains come to spiral around the lower extermity
Muscles innervated by the obturator nerve are __ which originate from ___
Adductor muscles
Originate from pubis
Muscles innervated by the femoral nerve are ___ and originate from ___
Quads and hip flexor muscles
Originate from anterior and medial surfaces of ilium
Muscles innervated by the common fibular and gluteal nerves are ___ which originate from ___
Gluteal muscles
Muscles of the anterior and lateral leg
Dorsal foot
Gluteal muscles originate from posterior and lateral surfaces of ilium
Muscles innervated by the tibial nerve are ___ which originate from ___
Hamstring muscles
Most lateral rotator muscles
Muscles of posterior leg
Plantar foot
Hamstring and lateral rotator muscles originate from ischium