 Hi everyone, I hope you're doing well. Welcome to today's anatomy and physiology lesson today We're gonna talk about the respiratory system And if you don't already know me, my name is Leah, and I'm your lee course instructor here at a CT So the respiratory system we all know that it helps us breathe and is very important for oxygen and So but the main functions of the respiratory system include of course the oxygen supplier like as we just mentioned and The job of the respiratory system is to keep the body constantly supplied with oxygen It also helps with elimination. So elimination specifically of carbon dioxide and the respiratory system functions With the help of gas exchange and the respiratory Systems organs facilitate that gas exchange that occurs between the blood and the external environment Also functions of the respiratory system include passageways, which passageways that allow air to actually reach the lungs and Also helps as a humidifier to help purify humidify and warm incoming air So components and the respiratory system include the upper respiratory tract and the lower respiratory tract The upper respiratory tract includes the nose the pharynx the larynx the organs of the upper respiratory tract are also located outside the chest cavity Conversely the lower respiratory tract these Organs are located inside the chest cavity and they include the trachea the lungs all segments of the bronchial tree including the avioli or Avilae I should say So the upper respiratory system we're just going to take a little bit of a closer look at at it here Includes the nasal cavity as we mentioned so inside the nose We all know there's a sticky mucosa Membrane lining that helps to trap dust particles dirt sometimes insects and And these tiny hairs called cilia then help to move them to the nose to be sneezed or blown out And then we have sinuses our sinus cavities our air filled spaces along the side of our nose That helped to make our skull lighter. Then we have the pharynx which both food and air passes through Um The pharynx before reaching their appropriate destinations, of course the food then passes to the esophagus and then into the stomach, but air goes from the pharynx down into The trachea on the lungs and then we have the larynx and this is um essential for human speech it helps us talk So, uh, the lower respiratory tract Um You can see a diagram of it here So some of these organs that we're going to talk about The trachea located just below the larynx And this is the main airway to the lungs Then of course we have the lungs and together the lungs form one of the body's largest organs And they're responsible for providing oxygen to capillaries and exhaling carbon dioxide With the bronchi and the bronchi branch from the trachea into um The trachea into each lung and they create a network of intricate passages that supply the lungs with air And then we of course have the diaphragm and the diaphragm is the main respiratory muscle That contracts and relaxes to allow air into our lungs So we're going to talk specifically about the lungs here right now just because the lungs are actually the center of the respiratory system um So as we've been discussing throughout the beginning of this Lesson that the lungs take in oxygen Which is obviously vital for the body's cells to live and carry out their normal functions The lungs also help to get rid of the carbon dioxide, which is a waste product of the cells The lungs are cone shaped as you can see here in this picture And they're made up of like a spongy pinkish gray tissue and they take up most of the space and the chest cavity The lungs are separated by The mediastinum an area that contains the heart and it's and the heart's large vessels The trachea the esophagus the thymus gland and also the lymph nodes so here's a diagram of Lung anatomy so of course we have the apex at the top of the lungs and this is just um The apex of the lung is actually just uh below the collateral bone As you can see right here You have the base of the lung Which is the bottom of the lung area and this is resting on the diaphragm the base of the lung The division so each lung is divided into lobes by fishers The left lung has two lobes and the right lung has three lobes so the left lung only has two lobes because It needs to make room for the heart Which is on the left side as well Then we have the bronchioles and this is the smallest of the conducting passageways And then we have The aviolye and these terminal the terminal bronchioles so the bronchioles lead to the respiratory what they call the respiratory zone Structures and then even smaller conduits that eventually terminate into The alveoli or air sacs So continuing on with the anatomy of the lungs So you have pleural fluid. So the pleural membranes produce a pleural fluid So it's like a slippery serious secretion that allows the lungs to glide easily over the thorax while during breathing movements So, you know, it just helps with that friction allowing the lungs to inhale and exhale Easily and it causes the two pleural layers to cling together. Then we have the pleural space In the pleural space, the lungs are held tightly to the thorax wall and the pleural space is more of Potential space than an actual one And then we have the pleura and this Plura is the surface of each lung is covered with a visceral Serosa called the pulmonary or visceral pleura and the walls of the thoracic cavity are lined with the parietal pleura So here is um a diagram here what I was just speaking about Earlier a few slides back called the respiratory zone. So as I mentioned it to you We have the bronchi that then We have bronchioles that branch off from the bronchi and at the end of each bronchi is this aviolar sac and this is where This this is the site of gas exchange and when I say gas exchange, I mean the exchange of Oxygen and carbon dioxide that's where this happens here in these aviolar sacs At the end of these bronchioles that are in the lung so Just a little bit of detail about respiration So the major function of the respiratory system as we've been talking about is to supply the body with Oxygen and disposed of carbon dioxide. So for this to occur four very distinct actions must Happen collectively known as respiration and these include first there's pulmonary ventilation. So air must move into and out of the lungs So gases and the air sacs That we just spoke about are continuously refreshed and this process is commonly known as breathing And then we have external respiration. So gas exchange between the pulmonary blood and the aviola Must take place Next we have respiratory gas transport. So oxygen and carbon dioxide must be transported to and from the lungs And the tissue cells of the body of the body via the bloodstream And then lastly we have the internal respiration So at um in systemic capillaries gas Exchanges must be made between the blood and the tissue cells So gas transport and exchange. So we touched on this two slides back in the respiratory zone This is just a little bit more detail about it. So of course, we have the aviola here again And this is just a diagram of actual gas exchange meaning the pickup of oxygen and the um The waste of carbon dioxide. So um an external respiration or pulmonary gas exchange involves the oxygen being loaded Here and the carbon carbon dioxide being unloaded here Internal respiration or systemic capillary gas exchange Get oxygen is then unloaded and carbon dioxide is loaded into the blood And then with gas transport Oxygen is transported into the blood in two ways first by attaching to Hemoglobin molecules molecules inside the red blood cells to formulate what's known as oxy hemoglobin Or a very small amount of oxygen is actually carried dissolved in our plasma of our blood And while carbon dioxide is transported in plasma as bicarbonate ion Or a smaller amount is carried inside red blood cells bound to the hemoglobin So mechanics of breathing seems very simple. We do it all day every day without even knowing it but um volume changes lead to pressure to pressure changes which lead to the flow of gases to equalize pressure So that's the rule the mechanics of breathing So with inspiration when you're taking a deep breath in air is flowing into the lungs Your chest is expanded the rib cage is elevated and the diaphragm is actually depressed and flattened Lungs are stretched to the larger thoracic volume while air flows into the lungs With expiration, of course When you're breathing out air is leaving the lungs The chest is depressed the rib cage is smaller and the diaphragm is now open or elevated Our lungs recoil to the smaller volume and air flows out of the lung Then there's something known as intra pulmonary volume and this is the actual volume That's left within the lungs We have intraplural pressure and this normal pressure within the plural space The intraplural pressure is always negative. So um, this is a major factor preventing um, our lungs from collapsing And then we have non respiratory air movement. So A result of like a reflex it a reflex activity such as hiccups or laughing crying yawning So it's important to understand respiratory volume and capacities when we talk about the respiratory system So something known as tidal volume um tidal volume is normal quiet breathing Which moves approximately 500 ml of air into and out of the lungs with each breath So that's tidal volume. Just normal quiet breathing Inspiratory reserve volume is the amount of air that can be taken enforceably over the tidal volume. So over what normal breathing is Which is normally between 2100 mls and 3200 mls Then we have that expiratory result reserve volume And this is the amounts of air that can be forcibly exhaled after a tidal expiration. So after a normal expiration the expiratory reserve volume Can force out approximately 1200 mls more Of air and then we have the residual volume So, um, there's always about 1200 mls of air that remain in the lungs. Um, and that cannot be voluntarily expelled So this is called residual volume and it is uh, it's important because it allows gas exchange to go on continuously Even between breaths and helps to keep the alveoli inflated And just continuing on with respiratory volume and capacities We have vital capacity And this is the total amount of exchangeable air that is typically around 40 100 mls and healthy young men and this respiratory capacity is incredibly important For a vital capacity, which is the sum of the tidal volume inspiratory resolve Reserve volume and the expiratory reserve volume We also have dead space volume So much of the air that enters the respiratory tract remains in the conducting zone Passagewaysion never actually reaches the alveoli So this is called the dead space volume enduring a normal tidal breath So again, normal tidal breath is just a normal inspiration So the air that enters the respiratory tract remains in the conducting zone Passagewaysion never actually reaches the alveoli Inspiration its amount is about 150 mls We have functional volume functional volume is The air that reaches the respiratory zone and contributes to gas exchange And then we have spirometer. So respiratory capacities are measured of course with with a spirometer We should all probably know that by now. So where and so when a person breathes The volume of air exhale can be read on this indicator which The indicator which is the spirometer which shows the changes in air volume inside the apparatus So a kind of short But very important anatomy lesson here about The respiratory system and the lungs especially Again, if you have any questions or concerns or you need any Being cleared up for you. You know that you can always email me Or you can set up a schedule office hours with me on my calendar Appointment book. So I will see you all again very soon. I hope you have a wonderful evening