Neurology | Sympathetic Nervous System

iron innards in this video we're gonna talk about the sympathetic nervous system have you guys haven't already please you'll watch the video in the introduction to the autonomic nervous system we discuss a little bit about a little brief introduction into talking about the different types of ganglia and a little bit on the sympathetic nervous and the parasympathetic in this video we're gonna go into a little bit more detail on the actual specific splanchnic nerves right and there are target organs and then the functions of those target organs okay before we do that I want to

talk about this the raku lumbar outflow alright so let's go ahead and talk about that first so if you remember we talked about this in the autonomic intro video that from t1 to l2 and again taking a little bit of grain of a salt there's some variants in there that sometimes it can be to l3 this is called the flora Co lumbar outflow it's a sympathetic outflow now where are these what are these blue things these blue things if you remember the cell bodies of the preganglionic motor neurons which are located in the intermedia lateral

column or the lateral gray horn i think that one's easier to say but either way remember that you can find these blue guys here these are the cell bodies of the preganglionic motor neurons of the sympathetic nervous system about a lateral grey horn or the intermediate lateral column all right now we're going to do is I want to talk about the outflows of these target organs so we have these things on the side here right these are called your ganglia what is a gang gang there's just a group of cell bodies in the peripheral nervous

system which is outside the CNS which is made up of the brain in the spinal cord right so outside of the brain in the spinal cord you have these groups of cell bodies they're called ganglia if they're located on the side they're called chain ganglia if they're located in front you remember they were called pre virtio or pre or tick or sub dial formatic or collateral a whole bunch of darn names for the same thing right well we're going to talk about and a lot of this video is the collateral ganglions okay which we're gonna

stick with collateral or pre vertebral right but I want to talk about these chang ganglia first these top ones this one right here have you come up an extension up here these chain going up lit to the cervical region right around like C to about this is actually you're gonna have what's called your superior cervical ganglion which are going to put scg you'll have another one at this level which is the middle cervical ganglion MCG or the inferior cervical ganglion which is the ICG but against there are some variants in different people sometimes the inferior

cervical ganglion is fused with t1 they call it the Stella ganglia not necessarily super important but again one of you guys to understand the variance here what I want to do is I want to talk about the preganglionic flow to the superior cervical ganglion and then out okay via to the head and neck structures that's we're gonna start with first so first things first generally from anywhere from about t 1 to t 3 ok about T 1 2 T 3 these guys can come out right so here's well here's what I'm I'm gonna bring this

guy in here it's not gonna sign ups in that chain ganglia it's gonna move upwards and it can sign apps on the cell bodies and the superior cervical ganglion and again this can come from t1 it can come from t2 or it could even come from t3 alright when these fibers move up they can move up through the inferior cervical middle cervical up to the superior cervical ganglion and sine apps and cell bodies here from this point they can then come out when they come out guess what these guys do you know there's a big

artery right there's a big artery here you know your heart you have the common carotid artery the common carotid artery actually bifurcates into the external carotid artery and the internal carotid artery what happens is you can have this nerve fiber kind of swirl around the internal carotid artery and when it does that it forms a special plexus we call this the carotid plexus and it can actually come off and go to different portions around the head in the neck the main ones we're going to talk about is going to be first the okay so it's

gonna supply a lot of different structures here okay the first one that we're going to talk about here is going to be the eye all right now if you remember those are the preganglionic the blue the black are the postganglionic they release Noro epinephrine there's only one exception to it and we'll talk about that and it's gonna be the sweat glands but we're here what's gonna happen is this guy's gonna release norepinephrine now what areas are gonna act on the eye you know there's around the iris you have a specific muscle there we talked about

in the actual special senses videos there's the the iris right it has what's called the dilator pupil a right and think about these things logically in a sympathetic situation your fight your flight your fright situations what are you gonna want to do let's pretend that I don't know Chuck Liddell he's getting ready to come at your he's chasing you what's gonna happen well you want to be able to see all different types of options right so what would your pupils want to do in that situation would you want to only see things like very small

amount of areas or would you want to be able to see a lot of stuff you want to see a lot of stuff so what's gonna happen is it's gonna release norepinephrine on this muscle here called the dilate or pupil a so what can I do you can act on what's called the dilator pupil a and when it acts on the dilated pupil a it causes pupillary dilation if you acts on the dilated pupil and causes people there dilation what does it allow for that allows primarily for far vision okay allows more light to come

in you're gonna have a little bit more exception for the far vision what else it's also gonna act on a muscle right here around the ciliary body they call it the ciliary muscle so it's also gonna act on the ciliary muscle called the ciliary when that contracts what it does is is it actually helps the lens to become more flattened when the lens becomes more flat and it helps us to be able to see very very far - it's called accommodation so the ciliary allows for what's called accommodation and this accommodation can lead to the

assistance in far vision right that's important then it's also gonna act in the member I said the head and neck region we got a lot of glands in this area you know we have the salivary glands like the submandibular the sublingual the parotid salivary glands right and even other glands too associated with this but these are your main salivary glands right so the main thing is gonna be your salivary glands so let's put here salivary glands and again remember submandibular sublingual parotid what's going to happen is they're gonna release chemicals like norepinephrine which can act

in two places one is that norepinephrine remember this was norepinephrine which is acting here you can also release norepinephrine which can act on two places one is it could act directly on the blood vessel it can act on the tunica media you know there's the tunica media the smooth muscle within the vessel wall which con trick s-- when it constricts it decreases the blood flow to the salivary glands which decreases the actual substances that you can take for these salivary glands to take from the blood and put into the saliva that's one important thing the

next thing is that also is going to act on the salivary glands directly there's different types of a generic receptors we'll have another video on that when it acts on the salivary glands it actually causes them to switch their mucus production into producing more mucin which is a glycoprotein which helps the thick thick in the mucus so it's gonna cause two different effects one it's gonna cause a thick viscous thick and viscous mucus production okay so it's gonna cause a thick viscous mucus production all right now what about other glands there's other glands with side

salivary glands in this area you know there's another one lacrimation right so you also have what's called these lacrimal glands so that other ones here called lacrimal glands now your lacrimal glands what happens is norepinephrine can also act on the blood vessels in this area constrict them decrease the blood flow through there which decrease the lacrimation or it could act directly on the lacrimal glands and decrease lacrimation right so it's going to try to decrease lacrimation okay so that pretty much covers this now what was this thing here called which comes off the superior circle

gang that they pretty much call this the carotid plexus okay all right that covers that part now the next thing here is I'm really important now there's other things that can come from the superior cervical ganglion actually can join on to some of the actual spinal nerves and if it joins with some of the spinal nerves that can go to supply your erector pili it can go to supply the actual blood vessels of vasomotor supply or it can also do what if you remember it can also code to the sudoriferous sweat glands okay which are

gonna be important for pseudo motor control which is sweat production all right but let's talk about these other ones here so now we're gonna have the middle cervical ganglion and the inferior cervical ganglion these can give off branches too but the most important branches for these guys are going to be specifically structures that are going to the heart the lungs and the esophagus okay so they're gonna give off fibers here and these fibers here are gonna go specifically to the heart the lungs in the esophagus okay now another thing is the superior cervical ganglion can

also give off some fibers too it can also give off so sometimes we call this the superior middle inferior cardiac nerve or plexus right and these are your sympathetic fibers and what they're doing is they're going to three different targets and what are these targets one is he can go to the heart if it goes to the heart attacks mainly on two different areas one is your nodal cells your nodal cells are important for heart rate so what it's gonna do is it's kind of try to increase the heart rate it's gonna try to cause

positive Crono tropic action so what's the overall effect here is gonna try to let's do a different color let's say it increases heart rate so one thing is it's gonna increase heart rate when they call in that positive Crono tropic action right another thing is to connect on the myocardium the contractile muscle cells if that happens it can increase the action power if that does that if we increase contractility we increase what's called cardiac output and if you increase cardiac output eventually that could increase your blood pressure okay that's a pretty cool thing there right

all right what else it can act in the esophagus and now generally you don't win every year in this flight or flight situation or you don't want to be able to worry about digesting food no you don't really care about that so it's gonna try to decrease peristalsis of the esophagus so for the esophagus it's going to decrease peristalsis of the esophagus and certain secretions of the soffits from the within the serum you because you have some tight certain types of glands within this area the esophageal glands okay the lungs the respiratory system the specific

area that is affecting though is the bronchi you know the bronchial smooth muscle there's bronchial smooth muscle here that actually control the diameter of the airway they control the airway resistance so if the sympathetic nervous systems gonna act here think about that what are you gonna do if Chuck Liddell's coming at me one of the toughest UFC fighters in history right what's gonna happen I'm gonna I'm gonna hyperventilate I'm gonna get really scared so you're gonna want to be able to allow for the dilation of the respiratory bronchials because you're gonna want to be able

to run away right have as much air getting into your your blood as possible as much oxygen cuz you want to run away from that guy alright so what's going to happen here it's gonna dilate the bronchioles so it's going to cause dilation of the bronchioles now another thing it can do remember that it actually does have the ability to go to the vascular smooth muscle I'm sorry the vascular smooth muscle within the blood vessels in this area now why that's important is is you don't want your blood vessels within the respiratory system to dilate

right because it allow for a lot of fluid to come into the area and leak out and make a lot of secretions you don't want a lot of secretions within the lungs because you want to have open area open Airways that you can get as much oxygen in and out so what do you want to do to the secretions you want to decrease it so two things can also have what happened here is it's also going to decrease secretions acting on the glans directly and it's going to cause vaso constriction of bronchial arteries make sure

that you understand I'm saying bronchial arteries I am NOT talking about the pulmonary artery these are completely different okay those are more auto regulated auto regulations that type of control okay cool now the next thing that we have to talk about is what do we call this well specifically if it's going to the heart what do we connect we call that we called it the cardiac plexus if it's going through the esophagus we're gonna call this the esophageal plexus if it's going to the lungs we're gonna call this the pulmonary plexus but here's one more

thing that we have to understand right so I said that it was mainly coming from the superior middle and inferior that's not always the case there's also other contributions remember I said here that there was t1 t2 t3 right well guess what else there's also going to be so you can have these fibers that can actually go straight up here or they can come and sign apps in this area so let's say that it actually sign apps is here or this guy comes over here so let's say now that it comes here in sign apps

is or it comes here in sign APS's comes here and sign APS's mainly t1 to t4 but you can have some contributions here from t5 okay so you can have t1 to about t4 but if you want we'll throw in another one there which is going to be t5 now what can happen some of the fibers from T one to T three can go up right so here let's show that kind of like this or some of them can go to the actual cell bodies within the chain gang remember what I told you they don't

have to go out through the crater in my communications they can go out as their own nerve what was that called it's called a splanchnic nerve and so some of these fibers here so t1 - two - three - four and again take it with a grain of salt there's a lot of variability here but even t5 and remember I'm saying a lot of variability because sometimes you're gonna read in different books that certain nerves might go to different ganglia and certain nerves might not go to this one certain my nerves might go to the

other one so just remember there's a lot of variability in these textbooks okay all right so that's that all right so we talked about the cardiac plexus esophageal pulmonary and the carotid now let's go to the next one the next thing we're going to talk about is we're gonna go to this structure called the celiac ganglia so we're going to go from a specific portion now we're gonna go because now we're getting ready to go into the abdomen and we're gonna go from t5 to about t9 now that's what we're gonna focus on okay so

we're gonna focus primarily here on t5 - t9 let me get this kidney and you're out of the way okay so first things first remember I told you some of these fibers they can go to a chain ganglia so I'm hoping they don't have to they can pass right through it right they can go into a collateral ganglia so now that's what we're going to talk about so let's say that this t5 passes right through t6 passes right through t7 passes right through t8 and teen ein pass right through there Chang ganglia they don't sign

apps there and they come out right as some type of splanchnic nerve this splanchnic nerve right here why do we call this bad boy we call this nerve the greater splanchnic nerve now the greater splanchnic there pretty much extends from t5 to t9 now what's the main ganglia that it's going to go to the main ganglia here that it's going to go to is going to be right around here you know that there's the aorta right you have the aorta and right around the aorta you have this paired ganglia this paired ganglia is actually gonna

be called the celiac ganglia so let's actually show that guy right here here's the cell body I'm just drawing one but remember there's multiple cell bodies here sign Asha's right there there's the ganglion what is this ganglion called this ganglion is called the silly AK ganglion and remember this is a pre vertebral or collateral now from the celiac ganglia on you member what the artery was that actually moves right where the silly I gang on the nerves are gonna move in that same area it's called the celiac trunk right solectron gives off multiple branches but

we're gonna pick the main the most common ones right so if we come up here look what's gonna happen here we're gonna have a heck of a supply here okay so what is this gonna be so silly right angle is gonna give branches off celiac trunk again and the celiac trunk if you remember it gives off multiple branches we're gonna focus on the common ones right big one right here stomach so it's gonna go to the stomach and when it goes to the stomach what do you think you're gonna want to do you're gonna want

to inhibit the actual peristalsis inhibit the secretions so two effects here for this guy inhibit peristalsis because again you don't want to be contracting your stomach and trying to focus a lot of that energy and muscles on on basically focusing on digesting food that's not your sole focus right so you want to try to inhibit the peristalsis another thing here is you're gonna want to try to inhibit some of the secretions there too but the main thing that we're gonna try to do here is remember the blood flow right the splanchnic circulation you don't really

want a lot of blood flow going to the stomach during a sympathetic situation so what are you gonna want to try to do to the actual blood flow to that area you're going to try to decrease it so we're going to do the vessels you're going to constrict the blood vessels so you're gonna constrict the blood vessels going to the stomach and if you do that by default it's gonna do two things one is it again it's going to decrease the absorption process alright because there is certain things that do get absorbed across the gut

specifically in the stomach like lipid soluble substances like aspirin and alcohol but another thing is it's going to decrease some of the actual sea creations okay there is another exception here where it actually can there's a sphincter muscle right here it's actually called the pyloric sphincter I'm not gonna talk too much about it but if you really do want to remember what it can actually do here is it can act on the pyloric sphincter and when acts on the pyloric sphincter it can constrict the pyloric sphincter to prevent time from moving from the stomach into

the duodenum basically slowing down the digestive process basically so if you do want to remember that it is a different one where it actually can cause contraction of pyloric sphincter they call this whenever that happens they call it the interrogation ik reflux okay which is basically inhibitory reflux it's very common and happens normally within the actual GI tract processes but anyway the reason why that's a little bit different is you might believe wait how is it causing contraction how is it inhibiting it here is dependent upon receptors for example this is alpha one this is

usually beta two okay but again we'll make a video on that specifically alright now we're gonna go to the liver the liver what is it gonna try to deliver the liver it's mainly gonna focus on trying to do a special thing here one of the special things about the liver is that the liver can actually break down glycogen into glucose which is important whenever our blood sugar levels and they need to be high so we can get our muscles contracting to be able to fight Chuck Liddell or run from Chuck Liddell right so what are

we gonna do here the big thing here is we're gonna do what's called glyco jeno lysis that's gonna be the big thing here we're gonna want to try to cause glycogenolysis trick to occur for the liver all right now the biliary tree here you're not gonna really want the actual gall bladder contractions to occur you're not gonna want to be able to release by are not really focusing on emulsifying fats and digesting and absorbing lipids right so you're gonna want to try to inhibit the biliary contractions right so you're going to want to be able

to decrease biliary tree contractions and flow yeah I like that I like that but let's say decrease biliary tree flow okay biliary tree flow because again you're not really focusing right now and trying to be able to get rid of the bile and help to cause the emulsification fat that's not really your focus at that point all right again the pancreas the pancreas you know that their structures here within the pancreas they called these guys the islets of langerhans and the islets of langerhans have alpha cells and beta cells now the beta cells are responsible

for secreting insulin all right the alpha cells are responsible for secreting glucagon now in this situation insulin wants to be able to decrease your blood glucose levels you don't want that you want to increase them so what do you think it's gonna do to the insulin production here it's gonna focus on trying to decrease insulin production and vice versa I want the other hormone to even act synergistically with me to enhance the blood glucose levels so I'm going to inhibit the beta cells but stimulate the alpha cells so I'm gonna want to try to increase

glucagon production here okay all right and there is fibers that can go to the splenic capsule here to the spleen not necessarily super important to be honest with you but it can cause the splenic capsule to have a slight contraction so it can go to the spleen and cause like a splenic contraction again not super important in this situation not really significant to the Senate the fight-or-flight response okay so the big thing here that we were able to grasp here is that from the celiac ganglia it's gonna supply the stomach cause the contraction the pyloric

sphincter inhibit peristalsis decrease absorption secretions it's caused like a general Isis decrease biliary tree flow and it's gonna try to inhibit the insulin production the glucagon production and increase glucagon production and again it can cause the splenic contraction of the the outer capsule also there is remember the celiac trunk does supply the proximal half of the duodenum and again if you remember that it's going to decrease the absorption in the secretions of that area also okay so it's not just the stomach but also remember the proximal half of the duodenum alright so we deal now

the greater splanchnic nerve has another point that it goes to and remember i'm telling you guys this because you have to understand that there is so much variability here now there is another part here right that the greater splanchnic nerve can have a branch that comes off here and goes to the adrenal medulla okay now these are odd because you're gonna notice here wait where the Frick is the ganglion in this case there isn't really any collateral gangly on this is a weird exception where we say that sympathetic preganglionic too short and sympathetic postganglionic so

long this is kind of like the opposite in this case so now the postganglionic are really short they're actually called in this area they call it the krama fin cells the krama fin cells are really important because they're acting like the postganglionic fibers and what happens is this is an example of what's called a intra mural ganglion okay you're like oh I thought that was just for the parasympathetic this is just one of the exceptions of the sympathetic and again as a result it can act on these chromaffin cells which are very cool because they

can release two different chemicals and directly into the circulation one is called Noro epinephrine and the other one is called epinephrine okay and these guys can go alway rides widespread they can have that very very widespread diffuse effect which is a very powerful effect as compared to parasympathetic which is more localized okay all right so that's that part so we can go to the intramural and okay what else there's another one the greater splanchnic nerve can also give off another fiber here and again remember take this with a grain of salt it's not always the

same thing it's not always clear-cut here but it can give off another one that goes to another ganglion okay there's another gangly on here and this guy is called the superior mesenteric ganglion so what are we gonna have right here we should have it's right here below it superior mesenteric ganglion okay and this one's really interesting also superior mesenteric ganglia remember the blood supply superior mesenteric artery so the actual superior mesenteric artery specifically supplied a couple different structures one is it can actually supply the cecum and it can supply the : it can supply the

actual transverse colon up to about around the actual left Colette flex like the proximal two-thirds and it can also supply the duodenum the distal half and it can supply the jus genome and the ileum right this is the easiest one to think about honestly if it's acting in this area right it's going to the duodenum the jejunum the ileum they're sending : what do you think it's gonna do anything the proximal two-thirds of the transverse colon it's just going to inhibit the digestive processes so basically the whole result out of all of this here is

it's gonna basically try to yeah we'll write this one coming down this right here the result of this is it's going to actually cause what decrease peristalsis what else decrease in the absorption because it's going to constrict the blood vessels and if it constricts the blood vessels it's not really relevant within the the large intestine but it is important within the jews and the ileum and the distal half of the duodenum but it's going to decrease the secretion processes also okay so again you can just remember decreased peristalsis decreases absorption and decrease the secretion if

you really want to be specific though the absorption of secretion is a little bit more important within a small intestine not as important within the the actual large intestine because they don't really play a big role in absorption they really only absorb water and electrolytes okay got that guy and if you want there is a little information that goes to the appendix but we're not going to talk about that all right so we got the greatest blanket care now we're going to go to the next guy whoa all right next one is going to be

from t 10 to t 11 so this was for the greater spike DIC nerve right this is going to be for what's called the LSN the lesser splanchnic nerve okay so t10 t11 again these preganglionic fibers come out what can they do they can just they can either sign apps they're become a part of the greater in my community cans and then go into the spinal nerve and supply pilo motor sudomotor vasomotor or they pass right through the frackers boom and boom if these guys come out what happens is and if it does it can

go to a gangly on now again I'm gonna keep saying this because there's so much variance in these text books but for the most part this is what I was able to find is that the actual t10 t11 they come to a specific gangly on and this ganglion is actually called the aorta Co renal ganglion right so we got t10 t11 which is gonna pass right through and then again what is this nerve call Lasser splanchnic nerve okay getting a little lazy sorry guys Lester's blank nerve now that would go to the article renal ganglia

they order Co renal ganglion will take these postganglionic fibers out and where are they gonna go they're gonna go specifically to the good old kidney all right so here let's have our kidney here let's have a ureter alright so we're gonna have this guy here so what they'll do is they'll synapse here in the article renal ganglia and the oracle renal ganga is gonna go to the kidney and it's actually gonna go to the ureter now when it goes to the kidney in the ureter what are you gonna try to do are you gonna try

to pee on Chuck Liddell no you don't want to pee on chocolate oh that might happen but that's not normal but what you want to do is is you don't want a lot of blood flow going to the kidneys and you don't really want to make urine so as a result what are the two things that you would expect to happen here one is I'm gonna decrease urine production okay that's one big thing what's another big thing well here's a little weird thing there's actually these things in here in the actual kidney we're not going

to zoom in on about the JG cells the juxtaglomerular cells the juxtaglomerular cells are really important why because what they do is they respond by beta-1 adrenergic receptors they can release a chemical called rennet and Reina can set off the angiotensin ii cascade which can cause aldosterone adh all these different hormones to get produced which are trying to increase their blood pressure so in that response what else could i have I could have what's called renin release okay but again remember the urine production it's usually due to what remember I said it's decreasing the blood

flow so it's gonna decrease the blood flow mainly by causing vasoconstriction to the blood vessels going to the kidney diverting that blood away from the kidney so we can send it to more important vital organs that's the same thing with the stomach again you're decreasing absorption is accretion or the entire GI tract if you're doing that you're constricting the blood flow to it so you can divert the blood away from those organs so you can send it to the muscles or the brain or other different organs needed for you to do the flight or fright

situations okay alright so we got that one t12 is pretty easy also this one's actually a little a lot easier it can pass right through t12 I mean it can go right through the chain ganglion and again I'm gonna keep saying it Davis with a grain of salt there is these weird type of cells diffuse ganglion cells and they're kind of like found like they're kind of diffuse and kind of wide spread around this area here I'm gonna kind of represent it like this these diffuse ganglion cells are important because when t12 the preganglionic fibers

didn't come and sign offs and some of these diffuse ganglion cells when they do these guys can enter into the kidney as a part of what's called the renal plexus right so what do we technically call this it can sign apps technically we call this the renal plexus okay which again can help to support the fibers from the auricle renal gangland by causing rain and release decreasing your in production but again more of it is trying to be able to decrease your in production another thing that can happen with the urine production is if you

don't want the actual your the contract what are you gonna want to do what you want to do the ureter you want to be able to decrease the peristalsis of the order because that's another effect that you can get out of the renal plexus and the fibers from the auricle renal dangling you're not gonna want the actually goethe to be contracting you don't want to focus on making urine right all right my darn knees all right so we got here t12 I guess I should tell you what this guy's called this is called the least

splanchnic nerve okay so this fiber right here I'm gonna denote it with LA actually one have two right here because I was the same thing here this is called the least splanchnic nerve okay okay we are so close guys all right let's do l1 and l2 in sometimes l3 okay these are gonna be your lumbar splanchnic s-- nerves okay lumbar splanchnic nerves so again l1 you can have this guy pass through el to pass through l3 pass through right now if they pass right through they don't go to the Cheng Englund this is kind of

important here they can continue to keep passing through here and here's where it gets kind of interesting we're gonna kind of come up over here alright and there's gonna be a ganglion over here okay there's gonna be a gangly on right over here we're gonna kind of finish what we didn't get to over here so now there's gonna be a ganglion over here where these lumbar splenic nerves can actually come to and innervate this ganglion is called the inferior mesenteric gangly on okay now from the inferior mesenteric dangle remember the inferior mesenteric arteries okay I

the infant has enteric artery what happens with the inferior mesenteric artery it supplies the descending colon sigmoid colon upper rectum and the distal 1/3 of the transverse colon now what do you think you're gonna try to do here the overall result you're gonna want to try to decrease peristalsis you're gonna want to try to be able to the main function to be honest with you is decrease the peristalsis here okay so as a result here the main function for this one is you're gonna want to try to decrease the peristalsis all right you're not gonna

want to try to poop or defecate in that type of situation that's for parasympathetic when you're calm and you're resting you're digesting defecating urinating all right so that's gonna be for that part all right so now we're gonna start with the innervation to the bladder and the internal urethral sphincter so we've talked about how l1 l2 and l3 can go out here now sometimes what can happen is something even from from t12 they can actually kind of come down here and so can l1 and l2 and even l3 here can actually what happens is sometimes

they can even pass down to l4 but either way nonetheless some of these fibers all the way down from about t12 sometimes even t11 down to about l2 l3 they can pass through right and they can come to an area right over here there's two plexi over here one it's actually draw it like this there's actually two plexi over here one is called the superior hypogastric plexus and the other one is actually going to be what's called the inter mesenteric plexus so again l1 l2 l3 and even t12 sometimes even t11 they can come down

right through these actual chain ganglia come out and they can go to two ganglion over one can be called the superior hypogastric plexus and the other one is called the inter mesenteric plexus so again what is this one right here called we'll put this as the superior hypo gastric gangly on or we can have over here this weird sucker called the inter mesenteric plexus this is actually in between as you can hear between the superior and inferior mesenteric arteries so it's kind of extending between these and allows for things to go up and go down

around that area but again what can happen is we're not going to talk about the things from the internet and tear because as I said things can go up into the superior mesenteric ganglion they can go down into the inferior mesenteric area so they can go and follow superior mesenteric artery or inferior mesenteric artery some of them can even follow some of the actual hypogastric nerves there are so many different areas that can come from this point so what I'm just gonna do here is I'll show that it can either go this way you can

go that way some of the fibers can actually even go over here okay so superior hypogastric ganglion gives these fibers here that can go to the internal urethral sphincter and can go to what's called the detrusor muscle okay so this big big muscle here which is basically the muscularis externa of this bladder is called the detrusor muscle if you watched our video on micturition reflex this will also give you a little bit more detail if you want but there's beta 2 and beta 3 adrenergic receptors in the detrusor muscle whenever it acts on that muscle

it relaxes the muscle it inhibits it from undergoing contraction so what is that going to do to this guy it's going to decrease contractions basically trying to prevent the process of voiding or micturition all right down here you have the internal urethral sphincter now this one's different now this one actually what happened it did contract guess what's gonna happen here the suckers gonna constrict prevent you from peeing your pants right so we're actually almost peeing your pants so there's actually alpha-1 a generic receptors in this guy but it's gonna act on this guy the internal

urethral sphincter and actually cause constriction or contraction of the sphincter but remember this is the internal urethral sphincter not the external externals under a voluntary somatic control all right now remember the superior hypogastric ganglion or plexus they call it this one's interesting and the reason why is is it actually gives off things called hypogastric nerves the right hypogastric nerve and the left hypogastric nerve and those are pretty much the main contribution into this last thing and we're gonna talk about called the inferior hypogastric plexus so I didn't want you to remember that the main input

going down into the actual gonads the ovaries and the testes is going to be the contributions from the superior hypogastric plexus the right hypogastric nerve left hypogastric nerve will eventually become the inferior hypogastric plexus but before we finish that off there's a part down here right so what happens is remember I said here remember I said from going to the bladder it could be from like l1 l2 l3 and it can even go out to the ganglion around l4 it can even be up to t12 T 11 well same thing for the gonads the going

adds can actually extend from t10 - so the t10 can actually give extensions and so can T 11 so you can have extensions from T 10 to 11 l1 l2 mainly from t10 to l2 okay so it's pretty much going to go to about l2 here what they do is they can come into these Chang ganglia right and they can come out around the sacral region of these actual Cheng angles around the sacral region and what happens with these guys is there going to go and supply the gonads okay so it's gonna go and supply

the gonads so for that you remember that there's the uterus for the female there's the vagina right there's also some of other tissues around that area like the actual oviducts the ovary for the male it's gonna be like the penis the scrotum right so around that area there so this is important so what is it gonna do okay for the male well what kind of effect would have in the male specifically it's designed to initiate ejaculation okay so you can remember this by parasympathetic point for the erection and sympathetic shoot for the ejaculation and then

for the female this one it actually is kind of interesting it can act on the uterus right and generally wants to cause the contractions of the uterus so it actually can cause uterine contractions but whenever a woman is pregnant what happens is it switches receptors okay from alpha 1 to beta 2 so that the uterus doesn't contract is you don't want to pop a baby out whenever you're pregnant right so it can change the remember uterine contractions is for non pregnant women but it does actually change when they're pregnant right it switches the receptors from

alpha 1 to beta 2 budding and causes uterine contractions or ejaculation within the male there's also other structures called the prostate gland within the male right the prostate gland the seminal vesicles that can actually cause those guys to produce what's called seminal fluid all right not as super important for these guys but again what is these these nerves here called these ones here son-of-a-gun these are called your sacral splanchnic so this area here is called your sacral splanchnic nerves and remember this one here going to the in fear mesenteric dangle and the in terment Erika

plexus and the super hypogastric is called the lumbar splanchnic s' and remember like I told you superior hypogastric ganglion can give off things called right and left hypogastric nerves so these can be what's called your hypogastric nerves and again the hypogastric nerves are the main contributor to this structure down here because what happens is the sacral splanchnic s' they come out to some diffuse ganglion cells out here also and what happens is the main main contributor that caught innervates the gonads the main one let's actually put this one in pink so that we can brighten

it up here is called the inferior hypogastric plexus okay so the in fair hypogastric plexus is the mange nerves they're gonna supply the gonads right and it can get two contributions very little of it very minut amounts come from the sacral psychic nerves from my teat and l2 but a good good good portion of them the more significant contributor is going to be from the super hyper gastric ganglion which splits it into right hypogastric nerves and left hypogastric nerves will eventually become and merge with the sacral antics and form what's called the inferior hypogastric plexus

which again will supply the gonads all right so before we finish this off on the sympathetic outflow you talk about one last thing I promise and this is gonna be some of the control so you know there's a tissue of gray matter which is a part of the diencephalon right here it's called the hypothalamus there's also other structures in here like for example you can have what's called limbic nuclei all right and even parts of your cortex but here's the important thing and the sympathetic nervous system actually has contributions from the hypothalamus and has contributions

from the limbic nuclei in certain situations it can even have cortical control also so sometimes it might even have cortical control not very much though but it can sometimes have some cortical control but for the most part the main ones is the limbic nuclei have a big effect on the sympathetic nervous system and the hypothalamus okay the only reason I say cortical control is that there's things called biofeedback techniques where you actually can like on your own control your heart rate so there is some weird situations in which there can be cortical controls but mainly

the limbic nuclei and the hypothalamus are some of the big big structures tissues of gray matter within the cerebrum that actually can contribute to innervating our stimulating the sympathetic nervous system because you can have these things like these presynaptic fibers that can come down and stimulate these cell bodies right here so again these presynaptic fibers they can come out and stimulate these cell bodies here and activate these preganglionic motor has to come out and stimulate the postganglionic and go and innovate the target organ so remember this sympathetic control can have kind of higher brain functioning

control right hypothalamus has sympathetic tissue that can actually have presynaptic fibers and come down and stimulate the cell bodies in the latter great horn or the intermedia lateral column and so can the limbic nuclei in certain situations where people can have biofeedback techniques they might even have a little bit of cortical control all right all right ninja nerds I want to thank you guys so much for watching this video if you guys did watch this video if you got through the whole thing man you guys are awesome I hope you guys like this video I

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