LUMBOSACRAL PLEXUS GLUTEAL REGION IN 25 QUESTIONS Kaan

LUMBOSACRAL PLEXUS & GLUTEAL REGION IN 25 QUESTIONS Kaan Yücel M. D. , Ph. D. 22. February. 2012 Wednesday 1

What do you think you will see about the lumbosacral plexus? Which muscles? Which functions? What is glutea? Gluteal region contents? Gun’s Roses- Godfather theme- Live in Copenhagen-1991 2

LUMBOSACRAL PLEXUS IN 17 QUESTIONS 3

1. What is lumbosacral plexus? Sensory and motor innervation of the whole. lower limb arises from the spinal roots L 1 -S 4 Lumbal plexus Sacral plexus 4

2. How is the lumbar plexus formed? Anterior rami of. upper 4 lumbar spinal nerves (+L 5) and from the contribution of subcostal nerve (T 12) in the lumbar region, within the psoas major muscle. 5

3. Nerves of the lumbar plexus? . L 1 gives rise to the iliohypogastric and ilioinguinal nerves L 1 + L 2 gives rise to the genitofemoral nerve L 2 + L 3 gives rise to the lateral femoral cutaneous L 2 + L 3 + L 4 give rise to the femoral and obturator nerves L 4 + L 5 give rise to the lumbosacral trunk which joins sacral nerves to form the sacral plexus. 6

4. . femoral nerve? (L 2 -L 4) largest branch. both motor and sensory. Emerges from the lateral border of the psoas major Flexors of the hip and extensors of the knee Skin of the anterior and lateral thigh, medial leg and foot 7

5. . saphenous nerve? largest cutaneous branch of the femoral. nerve continuation of the femoral nerve Skin of medial aspects of leg and foot 8

6. . obturator nerve? Emerges from the medial border of the psoas. major Leaves the lesser pelvis through the obturator canal Skin on the superior medial thigh Adductor muscles of the leg 9

7. . lumbosacral trunk? Descending part of the L 4 nerve unites. with the anterior ramus of the L 5 nerve to form the lumbosacral trunk Participates in the formation of the sacral plexus with the anterior rami of S 1 -S 4 nerves. 10

8. . ilioinguinal & iliohypogastric nerves? Enter the abdomen and run obliquely across. the quadratus lumborum muscle behind the kidney. Abdominal muscles Skin of the inguinal and pubic regions 11

9. . genitofemoral nerve? uinal & iliohypogastric nerves nerve? Pierces the psoas major and emerges on its anterior surface. Skin of the middle anterior thigh; male scrotum and cremaster muscle; female labia majora 12

10. . lateral cutaneous nerve of the thigh? Runs. inferolaterally on the iliacus and enters the thigh deep to the inguinal ligament/iliopubic tract Skin on the anterolateral surface of the thigh 13

11. . lumbar plexus & the sympathetic system? The lumbar plexus is also connected with the lumbar part of the sympathetic nervous system via two or three long communicating branches. 14

12. How is the sacral plexus formed? anterior rami of S 1 to S 4, and the. lumbosacral trunk (L 4 and L 5). formed in relation to the anterior surface of the piriformis muscle located on the posterolateral wall of the lesser pelvis. 15

13. . . sciatic nerve? o Largest nerve in the body. . o The most lateral structure emerging through the greater sciatic foramen inferior to the piriformis and enters the gluteal region o Posterior aspect of the thigh and the entire leg and foot 16

13. . . sciatic nerve? o Leaves the. gluteal region by passing deep to the long head of the biceps femoris, at the femoris lower margin of the quadratus femoris muscle o Divides into the common peroneal and tibial nerves, nerves at a variable site above the popliteal fossa 17

14. . . pudendal nerve ? o Main nerve of the perineum and the chief. sensory nerve of the external genitalia o Enters the gluteal region through the greater sciatic foramen inferior to the piriformis muscle & medial to the sciatic nerve. o Passes through the lesser sciatic foramen to enter the perineum. ono branches in the gluteal region. 18

15. . superior & inferior gluteal nerves? Superior gluteal nerve leaves the pelvic. cavity through the upper part of the greater sciatic foramen superior to piriformis muscle gluteus medius, gluteus minimus, and tensor fasciae lata Inferior Gluteal Nerve gluteus maximus post. thigh, leg, foot skin of the foot and lateral leg 19

16. . others? Nerve to Quadratus Femoris. Nerve to Obturator Internus Posterior Cutaneous Nerve of Thigh Perforating cutaneous nerve 20

17. . cocygeal plexus? o A minor. contribution from S 4 and is formed mainly by the anterior rami of S 5 and Co, Co which originate inferiorly to the pelvic floor. o Skin in the anal triangle of the perineum 21

GLUTEAL REGION IN 8 QUESTIONS 22

1. What is gluteal region? (G. gloutos, buttocks) transitional region between trunk & lower limbs. 23

2. How are the muscles of the gluteal region organized? Deep Superficial. 24

3. . . deep muscles of the gluteal region? . 25

4. . . superficial muscles in the gluteal region? . External surface of ilium between anterior and posterior gluteal lines External Ilium posterior surfacetoofposterior gluteal ilium between line; dorsal surface of sacrum anterior and coccyx; inferior Lateraland surface of Anterior surface of sacrotuberous gluteal lines ligament greater trochanter of greater trochanter femur of femur Iliotibial tract & gluteal tuberosity of femur 26

5. . . functions of the gluteal region muscles? Muscles in the gluteal region mainly abduct , extend, and laterally rotate the femur. relative to the pelvic bone. 27

6. . innervation of the gluteal region muscles? Superior gluteal nerve Inferior gluteal nerve Gluteus minimus & medius. Tensor fascia latae Gluteus maximus Nerve to the quadratus femoris Quadratus femoris Gemellus inferior Nerve to the obturator internus Obturator internus Gemellus superior Nerve to the piriformis Piriformis 28

7. . . arteries in the gluteal region? . 29

8. . . lymphatics in the gluteal region? Lymph from deep tissue superior & inferior gluteal lymph nodes. internal, external, common iliac lymph nodes lateral lumbar (aortic/caval) lymph nodes Lymph from superficial tissue superficial inguinal lymph nodes external iliac lymph nodes 30