[Music] hi everybody my name is andre welcome to med school eu in today's lecture we're going to continue talking about anatomy and physiology more specifically we will discuss the diseases associated with the circulatory and the respiratory system so today i'm going to give a quick introduction into some of the most common diseases associated with those two systems that we have discussed in the previous three lectures so first let's talk about some of the common circulatory system diseases and we will begin with some heart diseases so heart and the heart has many diseases but some of the most common ones are going to be the congenital heart disease so congenital heart disease is associated with any heart disease that occurs from birth it's any birth defects murmurs in the heart things like that they are all part of this one branch called congenital heart disease and it is qualified to be one of the most common types of birth defects next we're going to discuss myocardial infarction so this is a very common one this is the medical term myocardial infarction and this is just a common heart attack so heart attacks occur when part of the heart muscle does not get enough oxygen it does not get enough blood so then eventually that part of it dies out so if if you have for example blood a blood clot in the coronary artery which is the artery that supplies blood to the heart muscle so again every cell in the body needs blood it needs uh oxygen and needs nutrients and the heart is not an exception so when the heart pumps all blood all over the body it also must pump blood to its own cells its own cardiac cells and those the blood that goes through there it goes through these coronary arteries and typically when you've got a heart attack or myocardial infarction that is when there is a blockage in one of the coronary arteries which then part of the heart muscle is going to die out because it's not receiving enough oxygen supply so when the heart muscle does not receive enough nutrients enough oxygen supply for x amount of minutes that part of the heart is going to die out and it's never going to regenerate heart muscle unfortunately does not regenerate just like skeletal muscle does now we got something called cardiac arrest that is typically when the heart stops beating and it needs to be resuscitated and that is when the heart stops this is typically associated with an electrical problem so the sa node is not working properly or there's a blockage in the electrical activity of bundle of his or the av node basically the heart electrical activity of the heart is not stimulating it therefore the heart stops it stops doing its function and the person undergoes cardiac arrest where the heart is no longer beating and typically in more older and diseased individuals we get something called heart failure the general definition of heart failure is when the heart is not doing its function to the fullest so it's not able to pump enough blood around the body that is the general definition and it typically occurs when the heart becomes too weak or too stiff it does not have enough elastic fibers and it is just a frail heart now let's take a look at some blood vessel diseases so first one of the more common ones is aneurysm and aneurysms is basically just a bulge in the blood vessels so if you have a blood vessel running smoothly like this due to a weakness in one of the walls or parts of the walls you get this this bulge kind of like this so this bulge is called aneurysm and an aneurysm could burst and it could lead to a lot of a lot of problems and typically if it bursts if it's a major artery and there's a aneurysm that bursts in the major artery most do not make it to the hospital and they they bleed out because there's there's a crazy amount of blood pressure for example this is something that happens in the aorta or this happens in the pulmonary artery that's where there's lots of blood pressure going on and typically the person does not have favorable outcomes now we got terms like hypotension and hypertension and hypertension is basically high blood pressure hypotension is low blood pressure we got strokes we got thrombosis and well a stroke is obviously defined as a as a block in the brain block of blood flow in the brain and this could be caused by by various things like ischemia brain bleed or it could be caused by a blockage so thrombosis this is commonly defined as a blood clot all of these things could potentially lead to a stroke another fancy term is arteriosclerosis and that's typically just it's a chronic disease because it occurs over time and it's basically when the blood vessels are too stiff and become too thick to and that restrict blood flow and which of course may lead to blood clots like thrombosis but it restricts blood flow to vital organs and other tissues because the arteries simply become too thick and unable to stretch properly to modify for the blood pressure and finally looking at the blood diseases and typically these would be associated with the cells of the blood so first there's various kinds of anemia so we've got iron deficiency anemia so iron deficiency anemia if your red blood cells are low on iron they're not going to be able to carry as much oxygen as they can because again each of the hemoglobin molecules they also have iron in them and if the your body or your blood is iron deficient they will not be able to carry oxygen to its full capacity which may uh of course induce anemia another type of anemia would be aplastic and aplastic anemia is associated with the body not producing enough red blood cells and you're going to be red blood cell deficient which will obviously induce anemia as well we also got sickle cell anemia that's when the red blood cells are kind of in this semi-lunar orientation instead of nice and round they're they're kind of in these shapes and they're diseased because they're not able to carry as much oxygen and as much hemoglobin as the regular blood cells so of course it would induce anemia as well another very common one especially among children is leukemia and leukemia is due to high production of white blood cells so and and this would typically be immature white blood cells so our bone marrow that would be producing uh white blood cells at a certain concentration leukemia is when you've got cancer so leukemia is cancer of the white blood cells where they're going to be produced uncontrollably and they're going to take up space inside the blood vessels so there the composition of the blood is not going to be one percent white blood cells it's going to increase to a crazy percentage of white blood cells it's going to take up a lot more space so it's going to make the blood more viscous it's not going to flow as well and it causes all kinds of problems including anemia as well so leukemia there's lots of different types of leukemia but the more common ones are involved with the white blood cells another common one is called hemophilia and hemophilia is a genetic disorder you're going to see this a lot on pedigrees so hemophilia is again you're born with it typically and it is characterized by poor blood clotting so the platelets are not going to be doing their job very well and the it's going if you have a cut or you have internal bleeding it causes major major problems for the person because the blood is not able to clot or is not able to clot fast enough so you would get major bleeds and even just a little cut if if you cut your finger or or you cut your hand by accident this could be a major problem for hemophiliac patients and also hemophilia patients um if they have bruises that could be another major problem sometimes they have to go to hospitals because they got a little bruise and the bleeding cannot be stopped so hemophilia is another very dangerous and uh unfortunately it is a common blood disease so in the a-level textbooks uh the the british education system they talk a lot about effects of smoking and since the imat exam is made from cambridge university which comes from britain they're going to be taking a look at a lot of the a and a s levels in terms of the biology and the chemistry section so i figured it's important to know the effects of smoking the ingredients that are involved with it and how they're going to impact the respiratory and the circulatory system so some of the main components of cigarette smoke that pose a threat to human health are tar so we've got tar we got carbon monoxide and nicotine so that's the three major components that cause problems for people in general tar and carcinogens damage the gas exchange system and carbon monoxide and nicotine damage the cardiovascular system so the circulatory system primarily tar is a mixture of compounds that settles on the lining of the airways in the lungs and it stimulates a series of changes that may lead to obstructive lung disease and that's typically caused by tar it could also lead to lung cancer as well so that's the ingredient that leads to lung cancer when we've got a chronic smoker and of course carcinogens are also cancer-causing compounds that cause mutations within the genes that would control cell division so let's talk about chronic bronchitis chronic bronchitis typically occurs with most chronic smokers so the tar in the cigarette smoke stimulates goblet cells and mucous glands to enlarge and secrete more mucus so remember the goblet cells that were typically located in trachea and the bronchi those goblet cells and and the glands are going to produce more mucus more mucus than needed because of stimulation from the tar if you are a chronic smoker now the tar also inhibits the cleaning action of the ciliated epithelium that lines the airway so the airways are lined with with cilia now cilia are not going to be doing their function as well because they're going to be broken by tar so tar is going to basically inhibit or destroy the action of of cilia and cilia are used they're basically these projections that push all the bacteria and the viruses and all the all the bad stuff they push it back up the stream so you could cough it out and that's typically how a healthy lung behaves however when tar is going to destroy the cilia then there's going to be no cleaning action and when there's no cleaning action and a an increased production of mucus you're going to have mucus accumulating in the bronchioles and the smallest bronchials become obstructed so this leads to obstruction now this causes more problems because when mucus has not moved along this causes the viruses and the bacteria and all the germs to build up within the the bronchials that are are obstructed because there's no movement of air there's no cleaning action so this causes even more problems when bacteria and viruses actually collect inside of the bronchials and this typically what stimulates the smoker's cough then we've got scar tissue replacing the damaged cilia and of course scar tissue does not do any function other than just being there and arranged in a random manner and the smooth muscle surrounding the bronchioles and the bronchi become much thicker so this thickening of the airways causes them to narrow and makes it difficult to breathe and this is why there's there's an ease easier potential to be infected with things like pneumonia and and developing all of those viral infections so this entire thing all of these symptoms are going to be called chronic bronchitis this is when you get the smokers cough and they're chronically going to be coughing because of all the damage that tar has caused to the lining of the airways another disease we're gonna discuss is called emphysema so the inflammation of the constantly infected lungs causes phagocytes to leave the blood and line the airways and phagocytes are white blood cells that are there to do cleanup they're there to destroy things and they form this pus that would typically come out from an infected area in the body so the phagocytes are are these white blood cells that remove bacteria from there and they kill the bacteria and they remove it from there however there must be proper circulation to do that so to reach the lining of the lungs from the capillaries phagocytes release the protein-digesting enzyme called elastase and elastase breaks down elastic fibers and the problem with that is that the alveoli are of course they're lined with elastin fibers as you can see here all around in order for the alveoli to recoil and when you're breathing out the alveoli must recoil back to its original shape and the recoiling happens due to the elastin fiber now because the phagocytes are going to produce more elastase it's going to break down the elastin fiber around the alveolus and now it's not going to recoil as much as you can see here it's not going to recoil back to its original shape and elastin is responsible for that recoil and with with much smaller quantities of the elastin because it was broken down the alveoli do not stretch and recoil when breathing in and out and as a result the bronchioles collapse during expiration trapping air in the alveoli which often bursts so you get a bursting of the alveoli and it this reduces the surface area for gas exchange and the number of capillaries also decreases so less oxygen is absorbed into the blood so you are chronically going to have lower oxygen saturation and this is all caused by emphysema and that's again it's going to be from the chronic bronchitis because you get more infections that are not able to clear up and all of this is caused by tar now we're gonna discuss the cardiovascular system effects and that's gonna be the short-term effects by carbon monoxide and nicotine so nicotine is a drug in tobacco it is absorbed very easily by the blood and travels to the brain within seconds it stimulates the nervous system to reduce the diameter of the arterioles and to release a hormone called adrenaline from the adrenal glands so it causes vasoconstriction as it travels to the brain and release of adrenaline so what are the effects of vasoconstriction and increase production of adrenaline well typically you get an increased heart rate and blood pressure heart rate and bp and there's going to be a decrease in blood supply to the body and typically that's going to be decreased blood supply to the hands and the feet to the extremities and due to the increased heart rate and blood pressure and vasoconstriction this increases the risk of blood clotting another problem with nicotine is that it is highly addictive drugs so it increases the production of dopamine and each time that you have those short-term effects of nicotine you get a release of dopamine therefore it is this is why smoking is addictive now the problem with uh carbon monoxide so the co problem and there's something called co poisoning carbon monoxide poisoning this is why you have carbon monoxide detectors at home because when carbon monoxide enters and it diffuses into the alveoli and it enters into the blood from the lungs it diffuses into the red blood cells very easily and it combines with hemoglobin combines with hemoglobin and it permanently disables hemoglobin so hemoglobin has high affinity for oxygen it has a bit lower affinity for carbon dioxide but it has even higher affinity for carbon monoxide what this means is that now the red blood cells that have taken up carbon monoxide are not able to take up oxygen because that space is filled up with carbon monoxide so the hemoglobin each molecule hemoglobin that would take up four oxygen molecules it would take up carbon monoxide instead and now oxygen cannot bind to them because carbon monoxide has restricted that binding site and the quantity of oxygen transported in the blood may now be five to ten percent less in a smoker than an announced non-smoker so of course there's going to be various effects of this there's going to be less oxygen supply to the heart muscle putting a strain on the heart which is obviously also going to increase heart rate and increase blood pressure and another thing is that carbon monoxide may also damage the lining of arteries it may damage the endothelium so now we're going to briefly distinguish the difference between restrictive and obstructive lung diseases so we have our two columns one we'll discuss obstructive and one restrictive diseases so obstructive disorders are typically characterized by the reduction in airflow so this is going to be characterized by shortness of breath so exhaling is going to be the problem with obstructive diseases so the air is going to remain inside the lung after complete expiration and it could lead to diseases like copd and commonly asthma as well now if we're looking in contrast to obstructive the restrictive diseases it is characterized by reduction in lung volume so we got lower lung volume so it's difficult to breathe in obstructive is difficult to exhale restrictive is difficult to inhale and it's due to stiffness inside the lung tissue or or the chest wall cavity so it's due to stiffness this is a diseases that are called stiff lungs so it's stiffness because they don't have enough elastic fibers and you cannot breathe in as easily you have to work a lot harder with your muscles in order to stretch all of those tissues because elastin fiber is missing and this could lead to something called interstitial lung disease again this is because your muscles have to work harder in some areas versus others so you're going to get scoliosis in the spine there could be other neuro neuromuscular causes and marked obesity as well now this is a neat chart to memorize for the imat exam and specifically for this course because most lung diseases and most respiratory diseases are going to be qualified under one of these categories obstructive or restrictive so this concludes our lecture on the diseases associated with the respiratory and the cardiovascular systems [Music] you