Practical Nursing Skill Demonstrations · Transcript · · Updated
BSF Vascular system Part 1 – Transcript
Video by Practical Nursing Skill Demonstrations · Watch the original on YouTube
Use this video with Pro
Reading, copying and transcript downloads are free. Create saved AI results for this video with a signed-in Pro account ($9/month).
Transcript
Search ignores accents. All transcript text stays visible.
hey guys this is your chapter 13 the circulatory or vascular system um let me go ahead and share my screen it will let me okay
all right first thing we've got the functions of the vascular system is to exchange materials between the blood and the tissues so if you think about it like this it does the whole body and let's say that i exercised i went out i
walked just kind of exaggerate what i'm trying to say and my leg used all the oxygen and nutrients that it had stored there while i was walking so i need to replenish that so i have arteries that run
through my body that will take oxygenated blood to wherever it is that needs it and then they will release the oxygen and the nutrients into out of the vessel into the tissue fluid so that my leg has now more nutrients and more oxygen to use to finish my walking okay
so keep that in mind because we're going to come back to that now also remember that the vessels have a job of helping to maintain the blood pressure and remember we talked about that in another chapter but so if a person let's see
he's in a car wreck and they're bleeding and so they're losing blood they're losing blood volume okay so if you think about it when you have um you go to your water hose so we're back to the water hose when you go to the water hose and you turn down the amount of
water coming out of that water hose what happens to the pressure it goes down right if i turn up the amount of water coming through that water hose what happens to the pressure it comes up so think about that with your body so in order to maintain blood pressure the body says oh my gosh our blood pressure is too low so
it's going to do what it's going to vasoconstrict okay and then that's going to cause the blood pressure to increase remember with the water hose my illustration of constriction is if i take my thumb and i put it over the end of the water hose it makes that hole smaller just like vasoconstriction and then right can i squirt farther that
means the pressure's higher okay on the opposite if i'll take my thumb off or vasodilate make the opening bigger then my blood pressure is going to do what it's going to go down okay so if i'm spraying with my hand i'm going i'm just have high pressure because i'm squirting
way away and when i lift up that thumb it gets bigger the hole gets bigger and the pressure goes down so that's vasodilation all right arteries um arteries carry blood from the heart all the way to the capillaries okay
now remember that we have capillaries all over our body um from their head to our toe and they're in areas where they can drop off oxygen and nutrients okay so don't think of capillaries being in one place capillaries are all over the body okay and then we have smaller arteries which are arterioles
they're just a little bit smaller and then we have um we have to know that the arteries their outer and middle layers are thick because arteries are under much more pressure so therefore we do not want them to burst so there are three layers to the arteries that you need to know so the first one is your tunica intima it is the innermost layer it's made of
simple squamous endothelium and so it's very smooth and we want it to be smooth so that it doesn't cause clots to form if it's rough clots can form and that's dangerous we want it to be very smooth the middle layer is tunica media it is made of smooth muscle and remember smooth muscle we cannot control okay that's out of our control and
elastic connective tissue so that it can stretch right as blood comes through it so both are involved in the maintenance of normal blood pressure especially diastolic blood pressure the middle tunica media now the outer one is tunica externa it's made of fibrous connective tissue remember we said that fibrous connective tissue is very
strong and so it prevents it from bursting okay it's that outer covering just another way to prevent that it does not burst okay so you have two of them that do that the elasticity allows it to snap back right without bursting and then you have of course that strong fibrous connective tissue
that also keeps it from bursting that's your arteries so they come out of the heart with nice oxygenated blood okay so i got this picture here out of your book so it's on page 296 in your book so i want you to kind of be able to envision what i'm talking about so these are
capillaries right here so we said that we're going to use red for the artery see and blue is the vein so this just shows that arteries are thicker than veins okay and um
i also want you to note that where's my cursor there it is okay so you've got your artery which is the biggest one and then look right here see this little section coming out see how it's smaller than this overall piece right here this is an arterial so it's just a smaller part that comes off the artery and then look here this section right
here is the capillary now remember the capillary is where we drop off oxygen and nutrients and then we pick up the waste products that we want to get rid of okay so it comes over here so this is the arterial end and then it comes over here to the venous end and look it gets
it forms a small vein and this is a venule so that's on the next one it doesn't go over so it's just a small vein and then from the venule it connects to the larger vein and of course the vein will bring it back to the heart and we start over again okay so here are the veins they carry blood from the capillaries back to the heart we already said the
smaller veins are venules they have the same three layers as arteries but the inner layer has a valve so let's look at that see right here it's got a valve and valves always prevent backflow which i should know from your previous chapters so what happens is they're more new the valves are more numerous in the lower extremities because like if i'm standing up
uh and walking it pushes blood up and then the valve doesn't let it go back down and then it'll push it up further and the valve won't let it go back down and then it'll push it up further so it's continually going back towards the heart um so like i said they're more numerous in the legs because that's where blood most often
wants to kind of pool because of gravity so we've got to have those more in those lower extremities okay anastomoses anastomoses are connections or joinings of vessels so it's going to be artery to artery or vein to vein okay artery to artery or vein to fame there's no artery to vein okay so the purpose is to provide alternate pathways for the
flow of blood if one vessel becomes obstructed all right so um what what does that mean so let's do arterial it ensures blood will get to the capillaries if an org of an organ to deliver oxygen and nutrients and remove waste products okay so let's say
that maybe in our client they have a they have um poor circulation all right so if they have poor circulation what happens is our bodies are amazing so they can start slowly as this starts developing
grow blood vessels or arteries that will go around that bad spots you know and so it completely bypasses the bad spot so it can get to where it's trying to go same thing with veins if we have somebody that has something in their vein it's gonna bypass slowly grow some vessels and bypass that bad part
so an anastomosis just provides an alternate pathway around a bad area so that the flow of blood can continue because our i mean if tissue didn't get blood then it would die so i think that's pretty cool that our body has the ability to do that
okay capillaries they carry blood from arterioles to venules okay so let's go back up here see arterioles to venules okay arterioles two venules all right so they are only one cell in thickness and that's important because if it's only one cell then it has the ability to
let oxygen get out and pick up the waste products let nutrients out pick up water or whatever else needs to go back into the blood okay so blood flow is regulated by a pre-capillary sphincter it can constricts and dilates according to the needs of the tissue so in other words if i'm walking then my legs need
oxygen so it will dilate so that my legs can get the eye of the blood that i need however if i don't let's say i'm just sitting on the couch and my legs don't need it they don't need any blood right now then it will constrict so that that blood can go somewhere else that's more needed all right