BSF Chapter 12 Heart – Transcript

00:21okay guys this is chapter 12 which is the heart which is one of my favorites so we're going to start the instruction function of course the function of the heart is to pump blood and it does so through the arteries the capillaries and the mains it is considered to be cone-shaped when I say cone shape this

00:48is what I'm talking about okay so kind of like a cone so the tip is the apex and that's this little tip right here so if it's inside my body and this of course is a lot bigger than when actual heart is it's going to be pointed down like this okay so the tip is just above the diaphragm the diaphragm is right where like the band of a bra and a

01:15woman would be that's where the diaphragm is so it's to the left of the midline so it's going to go that way okay like the mediastinum the media song is in the thoracic cavity is the space that is between the lungs and that's where the heart of course sits now these membranes you should be familiar with we have had them before the pericardial

01:42membranes are the membrane specific to the heart so the first is the fibrous pericardium the fibrous pericardium is the sack that the heart is in okay so that's the sack then we have the parietal pericardium and if you remember from the previous chapters parietal needs to line a cavity so in this case

02:05there is no cavity but there is the the sack so it is a cavity really I yes inside that sack so that's where the parietal pericardium is and then of course visceral means on the organ so that's the membrane is actually owned the organ the visceral pericardium and of course all of these the parietal and

02:31the visual are serous membrane so that means they put out a serous fluid and that keeps everything lubricated so as the heart's pumping inside it doesn't get stuck to the sac and so it keeps everything running smoothly now there are four chest chambers of the heart they're made of cardiac muscle which is

02:53called the myocardium so Myo means muscle car games heart heart muscle is lined with endocardium endocardium is the inside of the heart and it must be very smooth because remember if it's rough then platelets start to stick to it and we do not want that we don't want

03:14clots or anything like that in our heart so it has to be very smooth the upper chambers the two upper chambers of the heart are called the atria and the two atria up here at the top are in between them is a wall and that's the interatrial septum the lower chambers

03:40down here are the ventricles and again they have a wall in between the two ventricles and that is called the interventricular septum okay I so start at the right atrium that is where blood comes from the body so we get it from the superior vena cava which of course empties the upper body and the

04:05inferior vena cava which empties the lower body blood flows from the right atrium through a valve is called the atrioventricular valve become because it's between the atria and the ventricles so that's where you did a trio in tricular so it's between though right atrium and the right ventricle every time you leave a chamber you have

04:31a valid so I always remember that every time you leave a chamber you have a valve so this one here the this side on the right side is called the tricuspid valve because it has three flaps that close okay and the way I remembering is trite right try right that's how I know that there's three on the right side okay so that go into the right ventricle

04:58pushes it down in there and then the purpose of the valve is to prevent backflow anywhere in the body if there's a valve it is to prevent that right I'm sure I hadn't missed any notes here I did I do have this ring down as the vegetable contracts blood is forced behind the three bow flaps that forces

05:25them to close okay so when it starts to squeeze it slams that atrioventricular valve closed and that's one heart sound okay then we have the right ventricle so when the right ventricle contracts the tricuspid valve closes and blood is pumped to the lungs okay let's think about this we came in from the vena

05:52cavas into the right atrium we went through the tricuspid valve into the right ventricle so now we're in another chamber so means we have to go through another valve right so the right ventricle is going to pump to the lungs so we have to go out of the pulmonary semilunar both pulmonary semilunar valve and it again prevents that foot so it goes through the pulmonary semilunar

06:19valve and it goes through the pulmonary artery now this is deoxygenated blood and we know that deoxygenated blood is not supposed to be in arteries but in this case there's several cases in the body well in the venous where this happens and this is one of them so deoxygenated blood in an artery so that's to put an artery into the lungs all right

06:45so we have something called papillary muscles and chordae tendineae and they prevent the valve from turning inside out so have you ever seen a umbrella that a big ol gust of wind takes it and it flips it inside out so that's what we're talking about we do not want that to happen so we want to have strong spokes that keep it from

07:09turning inside out and if you will look you can see I hope these are the things that keep it from flipping inside out okay see the chordae tendineae the capillary muscles you can't really see one good on this side but there it is right there okay and that's what I'm

07:29talking about okay so I'm gonna go over it again from the vena cava superior inferior vena cava we come into the right atrium of the heart we go through the tricuspid valve into the right ventricle then we go through the

07:53pulmonary semilunar valve to the pulmonary arteries to the lungs okay then we come out of the lungs in the pulmonary veins so if you look here the left atrium receives blood from the lungs by way of the pulmonary veins again now this blood has been to the lungs so it has been oxygenated and now it's in a vein which is backwards so

08:20again this is another instance where it's not doing like the rest of the body so from so if he's into the left atrium then it goes through another valve and that is the mitral valve it only has two so it's also called a bicuspid and he drops down into the left ventricle okay and again it prevents backflow now we're

08:48in the left ventricle now the left ventricle is the most port and ventricle I think in the heart because the laws are thicker than the right ventricle because they have to have more forceful powerful contraction because they got to push it out to the rest of the body so it's bigger the walls are thicker and it has more power and this is what also helps us with our

09:12blood pressure the power of that vegetable so again we're in a chamber so when we leave the chamber again another valve so this is the aortic semilunar valve they have the same appeal a coordinating tonight to keep it from turning inside out and of course the end they order takes it right onto the body

09:36okay so I want to do something real quick before we leave this section here to help you you do need to know how the blood goes through the heart you do need to know that I said this is the easiest

10:02way for me to show you how then can you move this thing that one thing okay so this is the right side of the heart so we have the superior and inferior vena

10:18cava which are famous right vena gate comes into the right atrium then we have a valve because that's a chamber so

10:38don't try cuspid valve okay there we go into the right ventricle hey now we're going to another train verse that means we got to go through the veil so we're gonna go through though cuz we're going to the lungs and pulmonary means lungs so we go through the pulmonary

11:06my leader bow I'm just go right dick is out having a brain okay then after we go through the pulmonary semilunar by us we enter the pulmonary arteries got what I want you to go into both lungs and then we hit the lungs okay so this is the

11:31right side of the heart the right side of the heart okay so over here and the reason I write it like this is you'll see it'll help you learn it so we come back from the lungs through the pulmonary veins is the long back so we

11:51got a reading of a we drop into the left atrium then we have a veil so we have the mitral or you can call it the by

12:06cuspid same thing and that's a valve so that you have the left ventricle okay then we're going to have another valve so we're gonna do though because this is