[MUSIC] Linda, show us some important bony landmarks on the anterior chest. >> Sure, so we're going to begin with the jugular notch. I want you to feel for the soft area. And, this is a really important marker. So this is the beginning of this bone, which is called the manubrium. And I want you to bring your finger down the manubrium until you feel a rise. When you feel a rise, that's a really important landmark. It's so important that we've named three different names for it. It's called the manubrium sternal junction, it's called the sternal angle and it's also called the angle of Louis that we actually refer to as Louis. >> So why is it important? >> That's really important because that's your marker for the second rib. So find the jugular notch, come down at the angle of Louis, you're going to feel a bone, that is your second rib. Below it is your second intercostal space. Third rib, third intercostal space, etc. This is the body of the sternum that ends in the xiphoid process. >> Can you always feel the xiphoid process? >> Not always, if somebody has extreme musculature, it's difficult to feel. But you can always feel this costal margin. Remember, costal means rib, so this is your costal margin. And it's important to note when you look at the costal margin, the angle right here. That angle should always be less than 90 degrees. There's also some other landmarks that we want to talk about when we look at the chest. One of them would be this line. Remember this bone is the clavicle. We're going to take that clavicle and we're going to divide it in half. And that would be the midclavicular line. Similarly, if I took the sternum and I divided that in half, I would call it the midsternal Line. And these will be really important features later on when we listen to heart and lungs sounds. >> Are there any important vertical lines in the axilla? >> Yes, so we also need to be able to define where things are in space. And we're going to use these lines and we're going to term them anterior axillary line, midaxillary line, and posterior axillary line. >> Can you feel the anterior axillary line? >> Well, you can feel from the musculature coming down and then, I'm going to turn the patient. And posteriorly, we need to use bony landmarks to help us figure out where we are in space. And so this bone, obviously we know this bone is called the scapula. And we want to know some borders about it. So we have this superior border and we have the inferior border. Why do I care about the inferior border is that when I feel the inferior border I know that the inferior border is approximating the seventh rib, so I know where I am in space. Similarly I'm going to have to know where lungs are divided. So I'm going to have to use this area, so we know that this is the vertebral line. And if I drew a line down the middle that would be the midvertebral line. I'm going to take my patient and I'm going to bend the patient's head forward. Can you see that there's a bump there? That bump corresponds to typically with C7, so the seventh cervical vertebrae. >> And why is it called the seventh cervical vertebrae, is that the vertebra prominens? >> Yes, sorry, [LAUGH] Phil. So the vertebra prominens, there are 7 cervical, there are 12 thorasics. So we're going to start counting from C7, we're going to count down T1, we're going to count down T2, and we're going to count down to T3. At T3,this is a really important landmark because this is where the lungs are going to be divided. Can you see the line I'm making? So it's an oblique line. So the lungs are going to be divided into upper lobes and lower lobes by this oblique right and left fissure that separates upper lobe from lower lobe. >> We've now drawn the lungs and the lines of pleural reflection. And, Linda can you show us how these marking are used to do a chest exam? >> Sure, we begin by understanding those five lobes to the lungs. There are three on the right and there are two on the left. And the lungs rise 1 inch above the inner one-third of the clavical. So again, the lungs rise anteriorly, 1 inch above the the inner one-third of the clavical, and then you can see that we have a marking drawn here. This is divide upper lobe from middle lobe. So we use the angle of Louis marking again, which is your second rib, underneath that second intercostal space, third rib, etc., until I get to the fourth rib. At the fourth rib, I draw an imaginary line over to the fifth rib in the mid axillary line. Because the ribs curve what started the fourth is the same as the fifth therefore we call it a horizontal fissure separating upper lobe from middle lobe. Posteriorly the lung was divided from T3 which I'll show you right now. At T3, we take the patient, we bend the patient head forward. You see that there is a prominence there, it's typically C7. Underneath there feel for the first prominens T1, feel the second T2. At T3 we draw a right and left oblique fissure that divides the lung posteriorly into upper lobe and lower lobe. >> Linda, why can't we see the middle lobe in this view? >> Because there is no middle lobe, posteriorly. Posteriorly you're only going to get upper lobe and lower lobe. >> So you can only listen to it anteriorly. >> Correct, you will never be able to hear a right middle lobe pneumonia posteriorly. You are only getting upper lobe and lower lobe posteriorly. So again at T3, the right and left oblique fissures divide the lung into upper lobe and lower lobe and the line ends, again, at the sixth rib in the midclavicular line, so that's why we drew these lines before. So now we have right upper lobe, we have right middle lobe. And you can see anteriorly, we only have this much space for the lower lobe. >> So what are these dotted lines? >> The dotted lines are the pleural reflection, that is, the lungs end anteriorly at the sixth rib, at the eighth rib in the midaxillary line and the tenth rib posteriorly. But if you think about what happens when you take a breath, you take a deep breath in and if you can and what happens is this diaphragm pulls down and his lungs will go down into this recess. >> So now, where his right lung ended at the 6th rib, you can see that we're now going to extend to the 8th rib. So the 8th rib now anteriorly, the 10th rib in the midaxillary line, and the 12th rib posteriorly. His lungs will descend down to this pleural reflection on maximum deep inspiration. So the lungs are constantly in an active process of moving up, or moving down. >> We've now drawn the borders of the heart in red, and the position of the valves and the auscultation point for the valves. Linda, explain how you use this information to do a cardiac determination. >> Sure, so we'll begin by understanding that the heart lays in the chest anteriorly underneath the sternum over into the left midclavicular line. >> The top of the heart is called the base of the heart. You can see we have a right sternal border. This right sternal border is primarily the right atrium. Over here at the fifth intercostal space, left midclavicular line, that's what we call the apex of the heart. And the apex of the heart is the left ventricle. >> Here we have four valves drawn across the sternum obliquely starting about the third rib and going to the fourth intercostal space. And how they are is the first one is pulmonic, then we have aortic, then we have mitral, and then we have tricuspid. Those are where the valves are, but that's not where the valves are heard best. So now you need to understand, where will we listen? Where we'll listen is for each valve in a particular area. We are going to go back to the angle of Louis, again, knowing the angle of Louis is the marker for the second rib, the second intercostal space, on the right sternal border, where you can see the heart is not is where I hear the aortic valve best. So I will put my stethoscope right in that position, and listen for S1 and S2, which you know as lub dub. So I will listen here for the aortic area. Now I will move my finger laterally, staying again at the second intercostal space, but at the left sternal border, that will be pulmonic area. And again, I listen for S1, S2, or lub dub. I now move down one intercostal space. You see I'm staying on the left sternal boarder now. This is what we called Erb's point. Erb's point is the third intercostal space left sternal boarder. This is where S1 and S2 are heard equally as loud. >> I go down one more intercostal space. So now I am in the fourth intercostal space, left sternal border. This is the tricuspid valve, again, listening for S1 and S2. Now, I need to move over to the fifth intercostal space, left midclavicula line, I'm using that line again. And I am going to listen in this area, and this area is the mitral area. This area also is known as the PMI, or the point of maximum impulse. It is where the left ventricle hits against the chest wall. You can observe for it and then you can use your hands to palpate for this area. >> We now draw some of the important structures in this superior mediastinum, that is the region of the thorax immediately superior to the heart. And as we look here, we can see the arch of the aorta arching off to the right and coursing around behind the manubrium of the sternum, doing so close to the sternal angle, passing posterior to manubrium. And then we also draw the pulmonary trunk headed to the left and then dividing into the right and left pulmonary trunks. And then further dividing into the lobar arteries, three on the right and two on the left, as we discussed. In the midline here, we draw the tracheal rings. And then for reasons of clarity here, we've continued the trachea as a single line in the midline here. We can see it dividing into a right and left main stem bronchus. And we note here that the right main stem bronchus is shorter, straighter and more vertical then the one on the left. [BLANK AUDIO].
