Nerves of the Pelvic and Gluteal Region Flashcards Preview

Lower Limb > Nerves of the Pelvic and Gluteal Region > Flashcards

Flashcards in Nerves of the Pelvic and Gluteal Region Deck (19):
1

Lumbar plexus

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

2

T12 and L1 form...

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

3

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

4

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

5

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

6

L2, L3 and L4

Split into anterior and posterior divisions

7

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

8

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
• To ASIS
• Inferior inguinal ligament
• Over Sartorius
• Anterior branch- skin over lateral/anterior thigh
• Posterior branch – skin lateral thigh from greater trochanter distally to mid-thigh

9

Variations

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

10

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

11

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

12

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

13

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

14

Sciatic nerve - two physiologic nerves

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

15

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

16

Perineal branches of sacral plexus

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

17

Femoral branches of sacral plexus

o Skin posterior/medial thigh and popliteal fossa

18

Sural branches of sacral plexus

o Skin distal popliteal fossa

19

Coccygeal plexus

• Part S4, S5, coccygeal anterior rami