inguinal canal and spermatic cord so to understand really the inguinal Canal we need to review layers of the abdominal wall so this is showing a A sagittal section of the of the pel abdominal wall pelvis and perineum of a developing male uh it's in a schematic Where It's A sagittal section we're looking at a medial view to start with the most superficial layer of the abdominal wall is the skin epidermis and dermis these are going to these layers are going to sound familiar next is the hypodermis which is the camper fascia primarily fat and some of that Scarpas fascia that deeper more fibrous connective tissue that makes up the hypodermis next layer is the external oblique muscle and Associated aerosis and next is the internal Bleak muscle with Associated aerosis and then the transversus abdominis muscle and you'll recognize that it actually as that extends down to the parum are the muscle ends in the aerosis uh uses with the transversalis fascia shown in pink then the next is this preperitonal fascia the one that we call before so preperitonal because it's uh in front of but if you go down below we call this sub parital FASA sub means below and then behind we call it the retr peronal fascia and so collectively this is what we've been used term before extra solic fascia sometimes known as extra sosal fascia all synony and so uh the term that um and then there's that tesus sorry that's located within this extra solic fascial space this gubernaculum tesus don't worry about the name of it is a this connective tissue structure that pulls the test down from the retroperitoneal area to the sub peronal area and it's going to pull through uh projecting through taking all layers of the abdominal wall to make the scrotum I'm going to use the the term extra perenial fascia in space to describe that location the fascial space of the test and finally there's our prial perenium that uh salic SAC mesothelium that lines the internal wall of the abdominal cavity so there's our test now this picture shows the same thing just all those uh layers of the abdominal wall are layered and so as that test descends notice that it's now pulling all the layers of the abdominal wall with it until finally it's within the scrotal sac now the layers of the abdominal wall shown with that orange little semicircle and look at the layers of the spermatic cord the same colors same layers that are inside there that make up the spermatic cord and then eventually also the scrotal sack something to to to uh pay attention to I'm just showing now layers abdominal wall layers of spermatic cord is there's the peronal cavity and the ex extension of the perianal cavity is called the processus vaginalis it's this uh little sack that came with this test as it went through the wall but the tesus is not inside that processes vaginalis it's not in it the test is in that EP extra paranal fascial layer that processes vaginalis is this pocket of mesothelium that surrounds the test itself U with a little uh fluid so here's an anterior view of the inguinal region and the inguinal Canal is the canal that connects the test with the abdominal wall and so in green there is that inguinal canal and so the outside opening is called The Superficial inguinal ring and the one on the inside is called the Deep inguinal ring and the inguinal Canal is what connects those two rings and that's what the test descended through and that inguinal canal is bordered or bounded uh bounded I just made up that word uh the boundaries of um formed by the layers of the abdominal wall so what are those layers well first there's our skin normal then there's this within a sublayer of the skin is this dartis muscle and fasis it's smooth muscle it helps wrinkle the scrotal sac to allow for more heat to radiate out um and whether you remember that or not I don't care um in blue you'll notice the external oblique um muscle and aerosis and that it becomes the external spermatic fascia the outside layer that's surrounding and it's a step dissection so it doesn't show it but imagine that layer going all the way around surrounding the test now the inguinal ligament is literally just the inferior border of the external oblique AP neosis that attaches to the anterior Superior ilc spine and courses down and you don't see it it goes to the pubic bone through inguinal ligament um the next layer is our internal oblique muscle and Associated fascia so there's our internal oblique muscle and it courses down and becomes the cremasteric muscle and Associated fascia this is skeletal muscle and it contracts and it can pull the test closer to the body or relax to allow it to go farther away this is important because our body temperature is 37° Centigrade but for sperm to be um to mature it needs to be at 34° Centigrade so that's why the test is outside the body but if the body temper if the outside temperature drops such as going in very cold water the cremasteric muscle pulls the test closer to the body wall to make sure that the temperature doesn't drop so that cremasteric muscle can move the tesus closer or farther away by relaxation uh to the body wall um next we oh and then this I just wanted to show this picture that shows the internal oblique and then there's the cremasteric muscle so it's not in Step dissection you get this idea of muscle and fascia surrounding the test all right now the transverse transversus abdominus aerosis uh does not give any contribution to this spermatic cordin scrotal sack and so it's shown there you can see the color above but it doesn't go down below um transversalis fascia however does that transversalis fascia becomes our internal spermatic fascia that surrounds the whole inside this connective tissue of the spermatic cord and then we have our paral parium shown up above that's that mesothelium and salic Sac that lines the inside of the abdominal cavity and then theirs are tunic of vaginalis that surrounds the um that's the outpouching of the prial peratin around the test but notice they're not connected and the only time they're connected is going to be dealing with um an indir inguinal hernia that we'll talk more about or at least increases the risk of it but in normal individuals there is no connection between prial perenium and the tunic of vaginalis all right so the next is this extra peraonal fascia and the contents of the spermatic cord because they're in the same fascial plane so let's talk about the contents there's the ductus defin outlined in yellow also known as many people call it the vas Defence vas means vessel and this is not a v vessel that's why ductus deference is the best description the ductus Defence is responsible for transporting sperm during ejaculation from the test up through the spermatic cord through the inguinal Canal then back into the ejaculatory tuct in the prostate gland and out the urethan the penis ductus Defence very thick smooth muscle wall to move uh sperm at a fast rate the testicular artery this arises from the uh abdominal aorta and provides blood supply in this courses through that deep inguinal ring through the inguinal Canal Out The Superficial inguinal ring and provides blood supply to the test the pampin for plexus of veins is transporting blood the opposite direction and this is um and it's a it's a plexus so instead of just having one vein there's like three or four veins that wrap themselves around that testicular artery notice that and they're taking blood in the opposite direction the left pampiniform plexus of veins goes to the left renal vein and the right pampiniform plexus veins just goes directly to the IVC we'll talk more about that in detail in the posterior abdominal wall lecture and the ILO andral nerves and seen going between the transverse abdominis and internal oblique going through the inguinal canal and then into the spermatic cord recognize that it does not enter the Deep inguinal ring but it does enter the inguinal canal and comes out the superficial inguinal ring the genital branch of the genital femoral nerve that I do not have in my illustration though unfortunately um enters the Deep inguinal ring goes through the inguinal Canal comes out the superficial inguinal ring and also does sensory to that spermatic cord