[Music] in this session let us begin with the sacral plexus sacral plexus is formed from the ventral ramas of L4 L5 S1 S2 S3 as well as S4 nerves it lies in front of the pyforms deep to the pelvic fascia in the posterior wall of the true pelvis so here L4 L5 S1 S2 and S3 ventral rine divide into dorsal or posterior ventral or anterior branches so L4 nerve what you can see over here very clearly that L4 nerve is shared by both lumbar as well as sacral plexes so where we we discussed in the lumbar plexus that L4 nerve divides and larger upper part take part in the formation of Lumbar plexus and the smaller lower part joins with the ventral ramas of the L5 nerve to form lumbosacral trunk which contributes to the formation of the sacral nerve so the lumbo sacral trunk and ventral ramas of S1 nerve are separated by super ior gluteal vles so here the ventral ramas of S1 as well as S2 nerves are separated by inferior gluteal vle now let us discuss about various branches which are mainly arising from the sacral plexus so as you can see the three important nerves over here Superior Glu nerve inferior gluteal nerve and next one is the nerve to pyriformis so these are the three NSE what you can see over here and if you see the other branches which are arising from the sacral plexus the first one what you can see over here is nerve to the quadral femoris where it also gives innervation to the inferior Gus and next one is nerve to the operator internus where it also gives innervation to the superior gyus and next important nerve which receives fibers from both dorsal as well as ventral division is posterior femoral cutaneous nerve and the next one is the Perforating cutaneous nerve pudendal nerve nerve to the levitar Anna and cious muscles perennial branch of the four sacral nerve anoc coxial nerve coxial nerve all these are the branches which are arising mainly from the sacral plexus now let us discuss in detail about individual branches or individual nerves which are arising from from sacral plexus so here if you see the N py foris it has a root value of S1 as well as S2 mainly from the dorsal divisions and nerve to deliv an as well as cxus muzzle has a root value of S3 as well as S4 but arising from the vental divisions pelvic spanic nerves S2 S3 as well as S4 setic nerve has two components one is a common peronal as well as tibial component the common per arises from the dorsal divisions L4 L5 S1 as well as S2 but the TBL component arises from the vental division of the same nerve segments that is L4 L5 S1 S2 S3 nerves next is nerve to the quador femoris arises from the vental divisions of L4 L5 as well as S1 and ner to the operator internal also arise from the vental divisions of L5 S1 as well as S2 pudendal L S2 S3 as well as S4 is a root value but it arises from the ventral divisions of the same nerve segments but if you see the posterior cutaneous nerve of the thigh dorsal divisions of S1 as well as S2 as well as vental divisions of S2 as well as S3 combined to form posterior cutaneous nerve of the thigh and the superior Glu nerve arises from the dorsal divisions of L4 L5 as well as S1 and inferior Glu nerve arises from dorsal divisions of L5 S1 as well as S2 and at L is a Perforating cutaneous nerve it arises from the dorsal divisions of S2 as well as S3 so this is about individual branches as well as the root values for all the nerves which are arising from the sacral plexus now let us begin with uh individual nerves and we will discuss in detail the first one is the superior gluteal nerve so as you can see the superior glutalor glutalor from dorsal divisions of L4 L5 as well as S1 after it arises from the following uh segments it passes out of the pelvis along the superior gluteal artery above the py foris and next is the inferior glutalor gluteal nerve arises from the dorsal divisions of L5 S1 as well as S2 it passes out of the pelvis through the greater setic foramin along with the inferior gluteal artery as well as posterior cutaneous nerve of the thigh below the pyforms muszle and the third one is the nerve to the pyforms so nerve to the pyforms is formed from dorsal divisions of S1 as well as S2 and that's it we need to know about this and next is nerve to the quadratus femoris it is formed from ventral divisions of L4 L5 as well as S1 after emerging it passes out of the pelvis same through the greater setic foramin anterior to that of the setic nerve and next is nerve to the operator internus and this nerve to the operator internus is formed from the ventral divisions of L5 S1 as well as S2 it also passes out of the pelvis through the greater setic foramin between the setic as well as the pudendal nerves and next one of the very important nve what we are going to discuss over here is the posterior femoral cutaneous nerve so this posterior femoral cutaneous nerve also known as the posterior cutaneous nerve of the thigh it is a sensory branch of the sacral plexus it arises from anterior as well as posterior divisions of the anterior Ramy of S1 S2 as well as S3 nerves it supplies the skin of the posterior thigh bck and the posterior scre in the males as well as labia in females and next one is about nerve to the litar Ane and cxus muzzle it is formed from the vental divisions of S3 as well as S4 next is the pelvic spanic nerves these branches arise from S2 S3 as well as S4 they provide sacred outflow of the parasympathetic system they cause constriction of the spinter was and the spinter external and also causes dilation of arteries of erectile tissue of the penis and citoris during their erection next is a important nerve which is called as a setic nerve the setic nerve consist of two nerves common peronal and the tibial enclosed in a common sheet so the common peronal nerve is formed from dorsal divisions of L4 L5 S1 and S2 but the tibial component is formed from the vental divisions of L4 L5 S1 S2 S3 nerves anyway we are going to discuss uh in detail about the setic nerve separately in the individual nerve section next is about the pendal nerve for example when we are discussing about the pendal nerve it is lower and smaller terminal branch of the sacral plexus it is formed from the vental divisions of S2 S3 as well as S4 and next is the Perforating cutaneous nerve where the Perforating cutaneous nerve what you can see over here is mainly formed from the dorsal divisions of S2 as well as S3 it descends on pyriformis and cxus and passes between cxus as well as L Anna and then pieres sacur tuberous ligament and the gluteus maximus mainly to supply the Glu Skin So by this we completed about the sacral plexus as well as in detail gross anatomy about the individual branches which are emerging from the sacral plexus