Overview of the Respiratory System

I'm super excited because today we're going to be talking about one of my favorite systems. We're going to continue on with the AT&T's version 7 human anatomy and physiology portion of the exam and we're going to be focusing on the respiratory system. So let's begin by talking about the different parts of this system. When you breathe in, air is going to enter through your nasal cavity where it's going to be warmed, humidified, and filtered by the mucus and your hairs. These structures include visible nasal hairs. and microscopic cilia, which are hair-like structures. Next up, the air is going to reach our pharynx, which is the crossroads between where food is going to go down the esophagus and air is going to go down our larynx. Air is going to travel down our larynx, which is also known as our voice box, before it ultimately reaches our trachea. It's very important to note is that food should be traveling down our esophagus and not our trachea. The epiglottis is going to play a critical role, when it comes to preventing food from getting into our trachea. What's really cool about our trachea is that it has this intriguing cylindrical tube supported by these rings also known as cartilage which is going to help keep that airway open and allow air to pass through. The trachea is going to extend downward splitting into primary bronchi one leading to each lung. Speaking of the lungs there are two of them divided into sections known as lobes. you're going to find three lobes over here on your right lung and two lobes located on your left lung. Most notably, that left lung is also going to have something what we call the cardiac notch. It's a small indentation that accommodates the heart, making the left lung slightly smaller than our right. Our primary bronchi is going to split off into our secondary bronchi, then our tertiary bronchi, and then down into our brachials. So as we move down this system, you're going to find that the space that that air has to get through is going to become smaller and smaller and smaller. As we move even further down, you're going to see our terminal bronchioles are going to lead into our respiratory bronchioles that are ultimately going to lead down into our alveolar ducts. Each alveolar duct is going to be surrounded by clusters of alveolar sacs, which resemble grape-like structures. a comparison that many of them make whenever they're looking at this particular part of the structure. Contained in each one of these sacs, we're going to find alveoli. This is where the actual process of gas exchange takes place. You're going to need to know two terms when it comes to the T's, the conducting zone and the respiratory zone. In the lungs, the conducting zone and the respiratory zone serve distinct functions but are still interconnected. The conducting zone is going to include structures like our trachea, our bronchi, and our terminal bronchioles, which facilitate the passage of air to the respiratory zone but do not actually participate in the gas exchange. We like to call this space anatomical dead space, since no gas exchange takes place here. This zone's primary role is to warm, humidify, and filter the air before it reaches the deeper parts of our lungs. As we move down to our respiratory zone, this is where the actual gas exchange is going to take place. It is going to include structures like our respiratory bronchioles, alveolar ducts, as well as our alveoli. The alveoli, which are tiny sac-like structures, are pivotal as these are the sites where oxygen enters the blood and carbon dioxide is removed. The extensive surface area of the alveoli combined with their rich blood supply makes them highly effective for gas exchange. a critical process for maintaining the body's respiratory and overall metabolic balance. So as we discussed, the circulatory system is intimately connected with our respiratory system. The red blood cells traveling through our capillaries pick up that oxygen that we breathe in to distribute it throughout the body, and they also collect carbon dioxide as a waste product of our metabolic processes to be exhaled. However, the respiratory system doesn't work in isolation. It collaborates with other body systems as well. The skeletal system, which includes our ribs, help form a protective cage around our lungs. Additionally, our muscular system plays a crucial role when it comes to respiration. These structures include our intercostal muscles, which are located in between our ribs, the diaphragm that is situated beneath our lungs, and the muscles of our abdominal wall. All of these muscles work together to expand and contract the thoracic cavity, aiding in breathing. While you can control your breathing voluntarily, you'll find that it operates involuntarily most of the time. When you think about it, you don't really think about breathing, it just kind of happens. This is because our nervous system manages that autonomic control, using pH levels in our blood to help regulate our breathing. Speaking of pH, the pH scale measures hydrogen ion concentration. On this scale, acidic substances indicated by our lower numbers on the scale have higher hydrogen concentration, whereas basic substances which have higher numbers on our scale are going to have lower hydrogen concentrations. Therefore, an increase in carbon dioxide is going to lead to higher levels of hydrogen ion concentration in our blood, making the blood highly acidic. This change is going to be detected by sensors, and those sensors are going to send signals to our brain. In response, the brain is going to regulate our intercostal muscles, our diaphragm, as well as our abdominal muscles to increase the rate of breathing as well as the depth of breathing. This adjustment is going to help restore and stabilize the blood pH to around 7.5. for maintaining homeostasis. I want you to consider the adjustments your body makes during exercise. It's remarkable how finely tuned our system is, enabling the increase of our breathing rate and depth in order to match our body's metabolic demands. And then lastly, we're going to discuss the mechanisms of breathing as well as perfusion. So when we talk about breathing mechanics, we're really talking about two main processes. We're talking about inspiration, which is inhalation, meaning that we're breathing in. That's inspiration. And then we have expiration, which is also known as exhalation, meaning that we're breathing out. These are facilitated by coordinated actions of the diaphragm and our intercostal muscles. So when we talk about inspiration, this is an active process where the diaphragm and external intercostal muscles are going to play critical roles. The diaphragm, which is that dome shaped muscle that's located below our lungs is going to contract and flatten downwards. This contraction is going to increase the vertical dimensions of our thoracic cavity. Simultaneously those external intercostal muscles which are located in between our ribs are going to contract and they're going to pull that rib cage upwards and outwards. This overall action is going to expand that thoracic cavity in both the lateral and anterior posterior dimensions. This increase in volume is going to create negative pressure relative to the atmosphere causing air to flow into our lungs. In contrast, expiration is usually a passive process during normal restful breathing. Expiration involves the relaxation of our diaphragm and our external intercostal muscles. As that diaphragm relaxes, it's going to move upwards back into the original dome shape that we saw before, and the ribcage is going to move downward and inward as the external intercostal muscles relax. This overall reduction of the volume inside of our thoracic cavity is going to increase the pressure inside the cavity compared to that of the outside atmosphere, pushing that air outside of our lungs. It's important to note that during forced expiration such as like we see with vigorous exercise or even coughing, that expiration process is going to become more of an active process. This brings us to our next point. Perfusion and ventilation are two critical aspects when it comes to pulmonary physiology that work together to optimize gas exchange in the lungs. Ventilation refers to the movement of air in and out of our lungs. This process ensures that fresh air reaching oxygen is going to reach our alveoli and perfusion is going to involve the flow of blood to those alveolar capillaries. In this process, oxygen depleted blood is brought to the lungs from the body via the heart to be oxygenated and have carbon dioxide removed. The ideal scenario is when ventilation, which is our airflow, and perfusion, which is our blood flow, are matched and balanced in the various regions of the lungs. However, sometimes this process can become imbalanced. And that's when we see hyperventilation and hypoventilation. So hypoventilation occurs when the ventilation is inadequate in relation to the body's needs. You're going to see a reduced air movement into and out of the lungs, leading to an elevation in our carbon dioxide and a decrease in our oxygen. We also refer to these as hypercapnia and hypoxia. So I want you to think about it. What happens if we're not breathing appropriately, if we're breathing less than what our body needs, hence the word hypo, well, we're not going to be able to exhale enough of that carbon dioxide from our respiratory tract. So if we're not able to exhale that off, we're going to see an increase in our CO2. And also, we're not going to get enough oxygen in. So we're going to see a decrease in our oxygen because of that mechanism not working appropriately. So next, let's talk about hyperventilation. And this refers to a state where the rate... and the depth of breathing is increased excessively, leading to increased expulsion of CO2 known as hypocapnia and a rise of oxygen in our blood known as hyperoxia. This type of breathing can lead to respiratory alkalosis, which is a condition where the pH of the blood increases due to those lower CO2 levels because as we know, CO2 is a key component when it comes to our body's acid-base balance. It's important to note that both hypoventilation and hyperventilation disrupt the normal process of breathing as well as the balance of oxygen and carbon dioxide in the body. I hope that this video is helpful in understanding specifically what you need to know when it comes to the respiratory system on the ATITs version 7. If you have any additional questions, make sure that you leave them down below. I love answering your questions. Head over to NurseJungstore.com where there's a ton of additional resources available to you to help you ace those ATITs exams. And as always, I'm going to catch you in the next video. Bye.

When you breathe in, air is going to enter through your nasal cavity where it's going to be warmed, humidified, and filtered by the mucus and your hairs. These structures include visible nasal hairs. and microscopic cilia, which are hair-like structures.

Next up, the air is going to reach our pharynx, which is the crossroads between where food is going to go down the esophagus and air is going to go down our larynx. Air is going to travel down our larynx, which is also known as our voice box, before it ultimately reaches our trachea. It's very important to note is that food should be traveling down our esophagus and not our trachea.

The epiglottis is going to play a critical role, when it comes to preventing food from getting into our trachea. What's really cool about our trachea is that it has this intriguing cylindrical tube supported by these rings also known as cartilage which is going to help keep that airway open and allow air to pass through. The trachea is going to extend downward splitting into primary bronchi one leading to each lung.

Speaking of the lungs there are two of them divided into sections known as lobes. you're going to find three lobes over here on your right lung and two lobes located on your left lung. Most notably, that left lung is also going to have something what we call the cardiac notch.

It's a small indentation that accommodates the heart, making the left lung slightly smaller than our right. Our primary bronchi is going to split off into our secondary bronchi, then our tertiary bronchi, and then down into our brachials. So as we move down this system, you're going to find that the space that that air has to get through is going to become smaller and smaller and smaller.

As we move even further down, you're going to see our terminal bronchioles are going to lead into our respiratory bronchioles that are ultimately going to lead down into our alveolar ducts. Each alveolar duct is going to be surrounded by clusters of alveolar sacs, which resemble grape-like structures. a comparison that many of them make whenever they're looking at this particular part of the structure.

Contained in each one of these sacs, we're going to find alveoli. This is where the actual process of gas exchange takes place. You're going to need to know two terms when it comes to the T's, the conducting zone and the respiratory zone. In the lungs, the conducting zone and the respiratory zone serve distinct functions but are still interconnected.

The conducting zone is going to include structures like our trachea, our bronchi, and our terminal bronchioles, which facilitate the passage of air to the respiratory zone but do not actually participate in the gas exchange. We like to call this space anatomical dead space, since no gas exchange takes place here. This zone's primary role is to warm, humidify, and filter the air before it reaches the deeper parts of our lungs.

As we move down to our respiratory zone, this is where the actual gas exchange is going to take place. It is going to include structures like our respiratory bronchioles, alveolar ducts, as well as our alveoli. The alveoli, which are tiny sac-like structures, are pivotal as these are the sites where oxygen enters the blood and carbon dioxide is removed. The extensive surface area of the alveoli combined with their rich blood supply makes them highly effective for gas exchange. a critical process for maintaining the body's respiratory and overall metabolic balance.

So as we discussed, the circulatory system is intimately connected with our respiratory system. The red blood cells traveling through our capillaries pick up that oxygen that we breathe in to distribute it throughout the body, and they also collect carbon dioxide as a waste product of our metabolic processes to be exhaled. However, the respiratory system doesn't work in isolation. It collaborates with other body systems as well.

The skeletal system, which includes our ribs, help form a protective cage around our lungs. Additionally, our muscular system plays a crucial role when it comes to respiration. These structures include our intercostal muscles, which are located in between our ribs, the diaphragm that is situated beneath our lungs, and the muscles of our abdominal wall. All of these muscles work together to expand and contract the thoracic cavity, aiding in breathing. While you can control your breathing voluntarily, you'll find that it operates involuntarily most of the time.

When you think about it, you don't really think about breathing, it just kind of happens. This is because our nervous system manages that autonomic control, using pH levels in our blood to help regulate our breathing. Speaking of pH, the pH scale measures hydrogen ion concentration.

On this scale, acidic substances indicated by our lower numbers on the scale have higher hydrogen concentration, whereas basic substances which have higher numbers on our scale are going to have lower hydrogen concentrations. Therefore, an increase in carbon dioxide is going to lead to higher levels of hydrogen ion concentration in our blood, making the blood highly acidic. This change is going to be detected by sensors, and those sensors are going to send signals to our brain. In response, the brain is going to regulate our intercostal muscles, our diaphragm, as well as our abdominal muscles to increase the rate of breathing as well as the depth of breathing. This adjustment is going to help restore and stabilize the blood pH to around 7.5.

for maintaining homeostasis. I want you to consider the adjustments your body makes during exercise. It's remarkable how finely tuned our system is, enabling the increase of our breathing rate and depth in order to match our body's metabolic demands. And then lastly, we're going to discuss the mechanisms of breathing as well as perfusion. So when we talk about breathing mechanics, we're really talking about two main processes.

We're talking about inspiration, which is inhalation, meaning that we're breathing in. That's inspiration. And then we have expiration, which is also known as exhalation, meaning that we're breathing out. These are facilitated by coordinated actions of the diaphragm and our intercostal muscles. So when we talk about inspiration, this is an active process where the diaphragm and external intercostal muscles are going to play critical roles.

The diaphragm, which is that dome shaped muscle that's located below our lungs is going to contract and flatten downwards. This contraction is going to increase the vertical dimensions of our thoracic cavity. Simultaneously those external intercostal muscles which are located in between our ribs are going to contract and they're going to pull that rib cage upwards and outwards.

This overall action is going to expand that thoracic cavity in both the lateral and anterior posterior dimensions. This increase in volume is going to create negative pressure relative to the atmosphere causing air to flow into our lungs. In contrast, expiration is usually a passive process during normal restful breathing. Expiration involves the relaxation of our diaphragm and our external intercostal muscles.

As that diaphragm relaxes, it's going to move upwards back into the original dome shape that we saw before, and the ribcage is going to move downward and inward as the external intercostal muscles relax. This overall reduction of the volume inside of our thoracic cavity is going to increase the pressure inside the cavity compared to that of the outside atmosphere, pushing that air outside of our lungs. It's important to note that during forced expiration such as like we see with vigorous exercise or even coughing, that expiration process is going to become more of an active process. This brings us to our next point.

Perfusion and ventilation are two critical aspects when it comes to pulmonary physiology that work together to optimize gas exchange in the lungs. Ventilation refers to the movement of air in and out of our lungs. This process ensures that fresh air reaching oxygen is going to reach our alveoli and perfusion is going to involve the flow of blood to those alveolar capillaries. In this process, oxygen depleted blood is brought to the lungs from the body via the heart to be oxygenated and have carbon dioxide removed. The ideal scenario is when ventilation, which is our airflow, and perfusion, which is our blood flow, are matched and balanced in the various regions of the lungs.

However, sometimes this process can become imbalanced. And that's when we see hyperventilation and hypoventilation. So hypoventilation occurs when the ventilation is inadequate in relation to the body's needs.

You're going to see a reduced air movement into and out of the lungs, leading to an elevation in our carbon dioxide and a decrease in our oxygen. We also refer to these as hypercapnia and hypoxia. So I want you to think about it. What happens if we're not breathing appropriately, if we're breathing less than what our body needs, hence the word hypo, well, we're not going to be able to exhale enough of that carbon dioxide from our respiratory tract. So if we're not able to exhale that off, we're going to see an increase in our CO2.

And also, we're not going to get enough oxygen in. So we're going to see a decrease in our oxygen because of that mechanism not working appropriately. So next, let's talk about hyperventilation. And this refers to a state where the rate...

and the depth of breathing is increased excessively, leading to increased expulsion of CO2 known as hypocapnia and a rise of oxygen in our blood known as hyperoxia. This type of breathing can lead to respiratory alkalosis, which is a condition where the pH of the blood increases due to those lower CO2 levels because as we know, CO2 is a key component when it comes to our body's acid-base balance. It's important to note that both hypoventilation and hyperventilation disrupt the normal process of breathing as well as the balance of oxygen and carbon dioxide in the body. I hope that this video is helpful in understanding specifically what you need to know when it comes to the respiratory system on the ATITs version 7. If you have any additional questions, make sure that you leave them down below. I love answering your questions.

Head over to NurseJungstore.com where there's a ton of additional resources available to you to help you ace those ATITs exams. And as always, I'm going to catch you in the next video. Bye.

Transcript for:Overview of the Respiratory System

Transcript for:
Overview of the Respiratory System