Nerves of the Pelvic and Gluteal Region Flashcards Preview

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Flashcards in Nerves of the Pelvic and Gluteal Region Deck (19):

Lumbar plexus

• Anterior primary rami L1-L3, part of L4, some T12
• Located posterior to/in psoas major


T12 and L1 form...

- Iliohypogastric (T12, L1)
- Ilioinguinal (L1)
- Genitofemoral (L1, L2)


Iliohypogastric nerve

Iliohypogastric (T12/L1)
• Cranial end of lateral psoas major
• Crosses quadratus lumborum, passes iliac crest, enters intneral surface of transversus abdominis & internal oblique
• Lateral cutaneous branches – posterior gluteal area
• Anterior cutaneous branches – hypogastric region
• Muscle branches: transversus abdominis & internal oblique


Ilioinguinal nerve

Ilioinguinal (L1)
• Lateral border psoas major
• Caudal to iliohypogastric
• Parallel w/ iliohypogastric across quadratus lumborum to iliac crest, pierces trasnversus abdominis
• Communication w/ iliohypogastric: between transversus abdominis and internal oblique
• With sperm cord through superifical inguinal ring
• To medial thigh, root of penis, anterior scrotum


Genitofemoral nerve

Genitofemoral (L1, L2)
• Passes through psoas major to ventral surface
• Genital branch: joins spermatic cord and round ligament to supply lateral scrotum and adjacent thigh
• Femoral branch runs lateral to genital branch and deep to inguinal ligament in lateral femoral sheath to supply skin over anterior thigh


L2, L3 and L4

Split into anterior and posterior divisions


Anterior divisions of L2, L3 and L4

Obturator (L2,3,4)
• medial to psoas major
• enters pelvis under iliac vessels
• exitsthrough obturator canal

Accessory obturator (L3,L4)
• Present 10%
• Runs medial to psoas major m.
• Leaves pelvis by passing superior to pubic ramus
• Deep to pectineus in thigh, becomes a muscular branch
• May give off articular branch to hip


Posterior divisions of L2, L3 and L4

Femoral (L2,3,4)
• Travels through psoas major
• Distally, runs between psoas major and iliacus
• Leaves pelvis deep to inguinal ligament, lateral to femoral artery

Lateral femoral cutaneous (L2,L3)
• Middle/lateral border psoas major
• Over iliacus
• Inferior inguinal ligament
• Over Sartorius
• Anterior branch- skin over lateral/anterior thigh
• Posterior branch – skin lateral thigh from greater trochanter distally to mid-thigh



1. Iliohypogastric/ilioinguinal nerves can come from common trunk
2. Ilioinguinal nerve is absent with genitofermoral taking over innervation
3. Cutaneous branches of femoral nerve are variable


Sacral plexus

• Lumbosacral trunk: pats L4, L5-S3, part S4
• Medial to piriformis
• Converge at greater sciatic foramen
• All branches EXCEPT S4 branch into anterior/posterior divisions

***L4= Nervus furcalis > divided into two plexuses


Anterior division

Nerve to quadratus femoris/inferior gemellus (L4-S1)
- Greater sciatic foramen, ventral to sciatic n
- Articular branch to hip joint

Nerve to obturator internus/superior gemellus (L5-S2)
- greater sciatic foramen
- Reenters through lesser sciatic foramen to bturator internus


Posterior division

Nerve to piriformis (S2 or S1/S2)

Superior gluteal (L4-S1)
- Greater sciatic foramen superior to piriformis
- Superior branch to gluteus minimus
- Inferior branch to gluteus medius/minimus, tensor fascia latae

Inferior gluteal (L5-S2)
- Greater sciatic foramen
- Inferior piriformis
- Supplies gluteus maximus


Sciatic nerve

o Largest nerve in body, largest branch sacral plexus
o Anterior division: L4-S3
o Posterior divison L4-S2
o Supplies: posterior leg muscles, all muscles of the leg, foot, skin foot most skin leg, all joints in lower extrmity
o Greater sciatic formina inferior to piriformis
o Cranial end: rests posterior ischium btwn ischial tuberosity & greater trochanter of femur
o Crosses obturator internus tendon, gemelli m, quadratus femoris
o Accompanied by posterior femoral cutaneous and inferior gluteal artery
o Articular branches to hip joint
o One antaomic nerve


Sciatic nerve - two physiologic nerves

Two physiologic nerves in one connective sheath
- Tibial (anterior L4-S3)
- Common peroneal (posterior L4-S2)


Posterior femoral cutaneous nerve of sacral plexus

Posterior femoral cutaneous (S2, S3A, S1/S2P)
o Skin gluteal region, posterior thigh, perineum, upper leg
o Gluteal branches: Inferior cluneal – lateral to gluteus maximus


Perineal branches of sacral plexus

o Medial to proximal thigh, perineum, scortum, base penis/labia majora


Femoral branches of sacral plexus

o Skin posterior/medial thigh and popliteal fossa


Sural branches of sacral plexus

o Skin distal popliteal fossa


Coccygeal plexus

• Part S4, S5, coccygeal anterior rami