1. NERVE SUPPLY Somatic: Lumbar plexus. Somatic: Lumbar plexus. Autonomic : Sympathetic trunk. Autonomic : Sympathetic trunk. Aortic plexuses. Aortic plexuses.

2. LUMBAR PLEXUS It is the main nervous supply of the lower limb. It is the main nervous supply of the lower limb. It is formed from the anterior rami of the upper four lumbar nerves. It is formed from the anterior rami of the upper four lumbar nerves. It has a contribution from T12 (subcostal nerve). It has a contribution from T12 (subcostal nerve).

3. LUMBAR PLEXUS The plexus is formed in the psoas muscle. The plexus is formed in the psoas muscle. The branches of the plexus emerge from the anterior surface the lateral & medial borders of the muscle. The branches of the plexus emerge from the anterior surface the lateral & medial borders of the muscle.

4. BRANCHES OF THE PLEXUS Emerging from the lateral side : Emerging from the lateral side : Iliohypogastric (L1). Iliohypogastric (L1). Ilioinguinal (L1). Ilioinguinal (L1). Lateral cutaneous nerve of the thigh (L2&3). Lateral cutaneous nerve of the thigh (L2&3). Femoral nerve (L2,3&4 ) DORSAL DIVISIONS. Femoral nerve (L2,3&4 ) DORSAL DIVISIONS.

5. BRANCHES OF THE PLEXUS Emerging from the medial side : Emerging from the medial side : Obturator nerve(L2,3 &4) VENTRAL DIVISIONS. Obturator nerve(L2,3 &4) VENTRAL DIVISIONS. Fourth lumbar root of the lumbosacral trunk. Fourth lumbar root of the lumbosacral trunk. Emerging from the anterior surface: Emerging from the anterior surface: Genitofemoral nerve (L1&2). Genitofemoral nerve (L1&2).

6. ILIOHYPOGASTRIC & ILIOINGUINAL They enter the lateral and anterior abdominal walls. They enter the lateral and anterior abdominal walls.

7. ILIOHYPOGASTRIC & ILIOINGUINAL Iliohypogastric : Iliohypogastric : Supplies the skin of the lower part of anterior abdominal wall. Supplies the skin of the lower part of anterior abdominal wall. Ilioinguinal : Ilioinguinal : Passes through the inguinal canal. Passes through the inguinal canal. It supplies the skin of scrotum or labia majora. It supplies the skin of scrotum or labia majora.

8. LATERAL CUTANEOUS NERVE OF THE THIGH It crosses the front of the iliacus muscle. It crosses the front of the iliacus muscle. It enters the thigh behind the lateral end of the inguinal ligament. It enters the thigh behind the lateral end of the inguinal ligament.

9. LATERAL CUTANEOUS NERVE OF THE THIGH It supplies the skin on the anterior and lateral thigh to the level of the knee. It supplies the skin on the anterior and lateral thigh to the level of the knee.

10. FEMORAL NERVE It is the largest branch of the plexus. It is the largest branch of the plexus. It descends between the psoas and iliacus muscles. It descends between the psoas and iliacus muscles. It supplies the iliacus. It supplies the iliacus. It enters the thigh behind the inguinal ligament and immediately it divides into many branches. It enters the thigh behind the inguinal ligament and immediately it divides into many branches.

11. OBTURATOR NERVE It crosses the pelvic brim in front of the sacroiliac joint. It crosses the pelvic brim in front of the sacroiliac joint. It leaves the pelvis to enter the thigh by passing through the obturator foramen. It leaves the pelvis to enter the thigh by passing through the obturator foramen.

12. 4 th lumbar root It is part of the lumbosacral trunk. It is part of the lumbosacral trunk. It descends anterior to the ala of the sacrum. It descends anterior to the ala of the sacrum. It joins the 1 st sacral nerve. It joins the 1 st sacral nerve. It shares in the formation of the sacral plexus. It shares in the formation of the sacral plexus.

13. GENITOFEMORAL NERVE It descends in front of the psoas. It descends in front of the psoas. It divides into a genital branch and a femoral branch. It divides into a genital branch and a femoral branch.

14. GENITOFEMORAL NERVE Femoral branch : Femoral branch : Supplies a small area of the skin of the thigh. Supplies a small area of the skin of the thigh. Genital branch : Genital branch : It enters the spermatic cord. It enters the spermatic cord. It supplies the cremaster muscle. It supplies the cremaster muscle. It is the nervous pathway for the cremasteric reflex. It is the nervous pathway for the cremasteric reflex.

15. SYMPATHETIC TRUNK It is the continuation of the thoracic trunk. It is the continuation of the thoracic trunk. It is formed of (4-5) ganglia. It is formed of (4-5) ganglia. It enters the abdomen behind the medial arcuate ligament. It enters the abdomen behind the medial arcuate ligament. It descends along the medial border of the psoas muscle. It descends along the medial border of the psoas muscle.

16. SYMPATHETIC TRUNK It lies on the bodies of the lumbar vertebrae. It lies on the bodies of the lumbar vertebrae. It enters the pelvis by passing behind the common iliac vessels. It enters the pelvis by passing behind the common iliac vessels. The left trunk: close to the left border of the aorta. The left trunk: close to the left border of the aorta. The right trunk : behind right border of the inferior vena cava. The right trunk : behind right border of the inferior vena cava.

17. BRANCHES (1) White rami communicantes : (1) White rami communicantes : Carry preganglionic nerve fibers. Carry preganglionic nerve fibers. Connect the first two ganglia with lumbar nerves (L1&2). Connect the first two ganglia with lumbar nerves (L1&2).

18. BRANCHES (2) Gray rami communicantes : (2) Gray rami communicantes : They contain postganglionic nerve fibers. They contain postganglionic nerve fibers. They join each ganglion to a corresponding lumbar nerve. They join each ganglion to a corresponding lumbar nerve.

19. BRANCHES (3) Medial fibers : (3) Medial fibers : They join the sympathetic plexuses on the front of the abdominal aorta and its branches. They join the sympathetic plexuses on the front of the abdominal aorta and its branches.

20. BRANCHES (4) Infero- medial fibers: (4) Infero- medial fibers: They enter the pelvis in front of the common iliac vessels. They enter the pelvis in front of the common iliac vessels. They join branches from the sympathetic plexuses to form the superior hypogastric plexus. They join branches from the sympathetic plexuses to form the superior hypogastric plexus.

21. AORTIC (PREVERTEBRAL) PLEXUSES They contain the following fibers : They contain the following fibers : Pre and post ganglionic sympathetic. Pre and post ganglionic sympathetic. Preganglionic parasympathetic. Preganglionic parasympathetic. Visceral afferent. Visceral afferent.

22. AORTIC (PREVERTEBRAL) PLEXUSES The plexuses are : The plexuses are : Celiac. Celiac. Renal. Renal. Superior mesenteric. Superior mesenteric. Inferior mesenteric. Inferior mesenteric. Their postganglionic branches are distributed along the corresponding arteries. Their postganglionic branches are distributed along the corresponding arteries.

23. CELIAC PLEXUS It is formed of two ganglia connected by network of fibers surrounding the origin of the celiac artery. It is formed of two ganglia connected by network of fibers surrounding the origin of the celiac artery. It receives preganglionic sympathetic fro the greater and lesser nerves. It receives preganglionic sympathetic fro the greater and lesser nerves. The parasympathetic from the vagus. The parasympathetic from the vagus.

24. INFERIOR MESENTERIC PLEXUS It has the parasympathetic from the sacral parasympathetic (S 2,3&4). It has the parasympathetic from the sacral parasympathetic (S 2,3&4).

25. LUMBAR SYMPATHECTOMY It aims to produce vasodilatation in patients complaining from vasoconstrictor disorders. It aims to produce vasodilatation in patients complaining from vasoconstrictor disorders. The preganglionic sympathetic arise from (T11_L2). The preganglionic sympathetic arise from (T11_L2).

26. LUMBAR SYMPATHECTOMY They synapse in the lumbar and sacral ganglia. They synapse in the lumbar and sacral ganglia. The postganglionic fibers are distributed among the branches of the lumbar and sacral nerves. The postganglionic fibers are distributed among the branches of the lumbar and sacral nerves. Postganglionic fibers can pass directly from the lumbar ganglia to the common iliac and external iliac arteries. Postganglionic fibers can pass directly from the lumbar ganglia to the common iliac and external iliac arteries.

27. LUMBAR SYMPATHECTOMY As far down as the inguinal ligament. As far down as the inguinal ligament. Bilateral lumbar sympathectomy in male can be followed by loss of the ejaculatory power. Bilateral lumbar sympathectomy in male can be followed by loss of the ejaculatory power.

28. LYMPH DRAINAGE Lymph nodes : Preaortic. Lymph nodes : Preaortic. Para aortic (lumbar) Para aortic (lumbar) Lymph vessels : Cisterna chyli. Lymph vessels : Cisterna chyli. Thoracic duct. Thoracic duct.

29. PREAORTIC LYMPH NODES Celiac. Celiac. Superior mesenteric. Superior mesenteric. Inferior mesenteric. Inferior mesenteric. They are around the origin of the corresponding arteries. They are around the origin of the corresponding arteries. They drain the GIT (lower 1/3 of esophagus to upper ½ of anal canal), pancreas, spleen,gall bladder and most of liver. They drain the GIT (lower 1/3 of esophagus to upper ½ of anal canal), pancreas, spleen,gall bladder and most of liver.

30. PREAORTIC LYMPH NODES Their efferent vessels pass to the intestinal lymph trunk. Their efferent vessels pass to the intestinal lymph trunk.

31. PARA AORTIC (LATERAL) LYMPH NODES. Their afferent vessels are from : Their afferent vessels are from : Kidneys and suprarenal glands. Kidneys and suprarenal glands. Testes & ovaries. Testes & ovaries. Uterine tubes & fundus of uterus. Uterine tubes & fundus of uterus. Common iliac nodes. Common iliac nodes. Deep lymph vessels of abdominal wall. Deep lymph vessels of abdominal wall.

32. PARA AORTIC (LUMBAR) LYMPH NODES. Their efferent vessels form the right and left lumbar lymph trunks. Their efferent vessels form the right and left lumbar lymph trunks.

33. CISTERNA CHYLI It is below the diaphragm to the right of the aorta in front of the 1 st and 2 nd lumbar vertebrae. It is below the diaphragm to the right of the aorta in front of the 1 st and 2 nd lumbar vertebrae.

34. CISTERNA CHYLI It receives lymph from : It receives lymph from : Intestinal trunk. Intestinal trunk. Right and left lumbar trunks. Right and left lumbar trunks. Lower part of the thorax. Lower part of the thorax. Its efferent is the Thoracic Duct. Its efferent is the Thoracic Duct.