Heart, Lungs, and Diaphragm Function PDF

How the Heart, Lungs, and Diaphragm Work Together Name: The heart, lungs, and diaphragm work together as part of the respiratory system to keep your body alive and healthy. The lungs bring in oxygen from the air and remove carbon dioxide, a waste gas your body doesn’t...

How the Heart, Lungs, and Diaphragm Work Together Name: The heart, lungs, and diaphragm work together as part of the respiratory system to keep your body alive and healthy. The lungs bring in oxygen from the air and remove carbon dioxide, a waste gas your body doesn’t need. The diaphragm, a muscle under your lungs, helps you breathe by moving up and down to pull air in and push it out. The heart pumps blood through your body, carrying oxygen from the lungs to your cells and bringing carbon dioxide back to the lungs to be exhaled. Together, they form a system that makes sure your body gets the oxygen it needs to work properly. The Human Heart The heart functions as the body’s central pump, moving blood through a closed loop of vessels. It works continuously to maintain circulation. Each of the heart’s four chambers has a speci c role: 1. Right Atrium Receives oxygen-poor blood from two main veins: the superior vena cava (upper body) and the inferior vena cava (lower body). Contains a pacemaker, the sinoatrial (SA) node, which controls the heartbeat. 2. Right Ventricle Sends oxygen-poor blood to the lungs through the pulmonary artery. Prevents back ow with the tricuspid valve. 3. Left Atrium Collects oxygen-rich blood from the lungs via the pulmonary veins. Passes blood to the left ventricle through the mitral valve. 4. Left Ventricle The strongest chamber due to its thicker muscular walls, which allow it to pump blood through the entire body. The largest artery in the body. Pumps oxygen-rich blood to the rest of the body through the aorta, the strongest artery in the body. fi fl Heartbeats The number of heartbeats per day depends on a person’s age and resting heart rate, which varies between infants, teenagers, and adults. Here’s a breakdown: Heartbeats Per Day by Age 1. Infants Resting heart rate: 120 to 160 beats per minute (bpm) Calculation: 120 bpm × 60 minutes × 24 hours = 172,800 beats/day 160 bpm × 60 minutes × 24 hours = 230,400 beats/day Infants’ hearts beat faster because their bodies grow quickly and need more oxygen and nutrients. 2. Teenagers and adults Resting heart rate: 60 to 100 bpm Calculation: 60 bpm × 60 minutes × 24 hours = 86,400 beats/day 100 bpm × 60 minutes × 24 hours = 144,000 beats/day Effect of Fitness on Heart Rate People with a good tness regime often have a lower resting heart rate because regular exercise strengthens the heart. A stronger heart pumps more blood with each beat, so it doesn’t need to work as hard to meet the body’s oxygen needs. A well-trained athlete might have a resting heart rate as low as 40 to 60 bpm. Example for an adult athlete: 40 bpm × 60 minutes × 24 hours = 57,600 beats/day verses an adult, who does not exercises 80 bpm x 60 minutes x 24 hours = 115,200 beats/day fi  This means an athlete’s heart beats fewer times per day compared to someone who is less t, reducing wear and tear on the heart over time and improving overall cardiovascular health. How the Lungs Work: Pulmonary System The lungs make sure your body gets the oxygen it needs and gets rid of carbon dioxide, which is a waste gas. They are amazing organs because they can hold millions of tiny air sacs called alveoli, which are where the oxygen and carbon dioxide are exchanged. This process happens every time you breathe, keeping your body alive and healthy. On average, a human takes about 12 to 20 breaths per minute when at rest. Over time, this adds up to: 720 to 1,200 breaths per hour 17,000 to 30,000 breaths per day The exact number can vary depending on factors like age, activity level, or health. For example, babies breathe faster (about 30-60 breaths per minute), while adults breathe more slowly. During exercise or stress, the breathing rate increases to supply more oxygen to the body. 1. Air Passageways Air travels from your mouth or nose through the trachea (windpipe), dividing into two bronchi leading to each lung. The bronchi branch into smaller tubes called bronchioles, ending in tiny air sacs called alveoli. 2. Gas Exchange In the alveoli, oxygen passes into the blood while carbon dioxide exits. fi  This process happens through diffusion, where gases move from high to low concentration. 3. Pulmonary Circulation Blood ows from the heart to the lungs via the pulmonary arteries, then returns oxygenated via the pulmonary veins. The capillaries surrounding the alveoli are key to this gas exchange How They Work Together The heart and lungs work together as a team, exchanging gases like oxygen and carbon dioxide with the blood and continuously pumping it throughout your entire body. The lungs supply oxygen to the blood, while the heart ensures this oxygen-rich blood reaches every part of the body, and then carries carbon dioxide back to the lungs to be exhaled.. The right side of the heart sends blood to the lungs to pick up oxygen. The left side of the heart sends that oxygen-rich blood to the rest of your body. Your lungs ensure your blood always has the oxygen it needs to keep your body working. The Diaphragm The diaphragm is part of the respiratory system and plays a crucial role in helping you breathe. It’s a muscular system component and works as a skeletal muscle that controls the movement of air into and out of your lungs. 1. Structure: The diaphragm is a dome-shaped muscle located just beneath your lungs and above your stomach. It separates the chest cavity (where your heart and lungs are) from the abdominal cavity (where your stomach, liver, and intestines are). fl  Made of skeletal muscle, the diaphragm connects to the lower ribs, sternum, and spine. Has openings for the esophagus, blood vessels, and nerves. 2. Functions Beyond Breathing Assists in coughing, sneezing, vomiting, and even childbirth by increasing abdominal pressure. How the Diaphragm Works 1. Inhalation (Breathing In): When you inhale, the diaphragm contracts (tightens) and moves downward. This creates more space in your chest cavity, allowing your lungs to expand and ll with air. 2. Exhalation (Breathing Out): When you exhale, the diaphragm relaxes and moves upward. This pushes air out of your lungs, removing carbon dioxide from your body, because when you exhale you are forcing carbon dioxide out of lungs. fi How the Rib Cage Expands The rib cage is made of bones (ribs) and muscles (intercostal muscles) that protect the lungs and help with breathing. During inhalation (breathing in): 1. The external intercostal muscles contract, pulling the ribs upward and outward. This makes more space in the chest for the lungs to expand as they ll with air. During exhalation (breathing out): The internal intercostal muscles relax, and the rib cage moves back, making the chest cavity smaller and pushing air out of the lungs. There are two main types of intercostal muscles: 1. External intercostal muscles: These muscles pull the ribs up and out during inhalation (breathing in), making more room in the chest for the lungs to expand. 2. Internal intercostal muscles: These muscles help pull the ribs down and in during exhalation (breathing out), helping push air out of the lungs. Together, these muscles are key to the process of breathing, working with the diaphragm to move air in and out of the lungs. The Phrenic Nerve The phrenic nerve tells the diaphragm to move, and the brainstem controls your breathing automatically without you thinking about it. Hiccups happen when your diaphragm, the muscle that helps you breathe, suddenly tightens, or contracts, at the wrong time. This is often caused by the phrenic nerve, which controls the diaphragm, sending a sudden signal to make it move. Here’s how it works: Normally, the diaphragm moves smoothly up and down to help you breathe in and out. When the phrenic nerve gets irritated (from eating too fast, drinking soda, or even excitement), it sends a quick signal to the diaphragm, making it contract suddenly. fi  This sudden movement causes you to suck in air quickly, and the air hits your vocal cords, making the “hic” sound. Hiccups usually go away on their own once the phrenic nerve calms down! Essay Questions 1. Explain the role of the lungs in the respiratory system. Include details about air passageways, gas exchange, and how the lungs work with the heart to supply oxygen and remove carbon dioxide. 2. Describe the functions of the heart and its four chambers. Discuss the roles of the right and left atria and ventricles, and how valves ensure blood ows in one direction. 3. Discuss the role of the diaphragm in breathing. Explain how the diaphragm moves during inhalation and exhalation, its structure, and how it works with the rib cage and phrenic nerve. fl Fill-in-the-Blank Questions 1. The heart pumps blood through your body, delivering ________ to cells and carrying away ________. 2. The ________ works as the body’s central pump, continuously circulating blood. 3. The ________ is a muscle located below the lungs that helps you breathe by moving up and down. 4. The lungs remove a waste gas called ________ from your body. 5. Blood that lacks oxygen ows into the ________ side of the heart before traveling to the lungs. 6. The ________ are tiny air sacs in the lungs where oxygen and carbon dioxide are exchanged. 7. The ________ valve ensures that blood ows in one direction between the right atrium and right ventricle. 8. Oxygen-rich blood returns to the left side of the heart via the ________ veins. 9. The ________ ventricle is the strongest chamber of the heart, pumping blood through the entire body. 10. The diaphragm separates the chest cavity, where the lungs and heart are, from the ________ cavity below. fl fl 11. The movement of the diaphragm is controlled by the ________ nerve. 12. During inhalation, the ________ muscles contract, causing the rib cage to expand. 13. The heart has four chambers: two ________ and two ________. 14. The ________ is the largest artery in the body, carrying oxygen-rich blood from the heart. 15. People who exercise regularly often have a ________ resting heart rate because their hearts are stronger. 16. Oxygen enters the blood in the lungs through tiny capillaries surrounding the ________. 17. The exchange of oxygen and carbon dioxide in the lungs happens through a process called ________. 18. When the diaphragm contracts, it moves ________, making more space in the chest cavity. 19. During exhalation, the diaphragm relaxes and moves ________, helping push air out of the lungs. 20. Hiccups happen when the diaphragm contracts suddenly due to irritation of the ________ nerve. Key: 1.Oxygen, carbon dioxide 2. Heart 3. Diaphragm 4. Carbon dioxide 5. Right 6. Alveoli 7. Tricuspid 8. Pulmonary 9. Left 10. Abdominal 11. Phrenic 12. Intercostal 13. Atria, ventricles 14. Aorta 15. Lower 16. Alveoli 17. Diffusion 18. Downward 19. Upward 20. Phrenic Here are the answers to the essay questions: 1. Explain the role of the lungs in the respiratory system. The lungs are responsible for bringing oxygen into the body and removing carbon dioxide, a waste gas. Air enters through the mouth or nose and passes through the trachea, bronchi, and smaller bronchioles before reaching tiny air sacs called alveoli. In the alveoli, oxygen passes into the blood, and carbon dioxide is removed from the blood through diffusion. The lungs work closely with the heart to pump oxygen-rich blood to the body and return carbon dioxide-rich blood to the lungs to be exhaled. This gas exchange happens continuously to keep the body alive and functioning properly. 2. Describe the functions of the heart and its four chambers. The heart is the body’s main pump, moving blood throughout the body. It has four chambers: Right Atrium: Receives oxygen-poor blood from the body through the superior and inferior vena cava. Right Ventricle: Pumps oxygen-poor blood to the lungs through the pulmonary artery. Left Atrium: Receives oxygen-rich blood from the lungs via the pulmonary veins. Left Ventricle: The strongest chamber, it pumps oxygen-rich blood through the aorta to the entire body. Valves between the chambers, such as the tricuspid and mitral valves, ensure blood ows in one direction, preventing back ow. 3. Discuss the role of the diaphragm in breathing. The diaphragm is a dome-shaped muscle located below the lungs. It separates the chest cavity from the abdominal cavity and is essential for breathing. fl fl  Inhalation: When the diaphragm contracts, it moves downward, creating more space in the chest cavity and allowing the lungs to expand as air is pulled in. Exhalation: When the diaphragm relaxes, it moves upward, reducing space in the chest cavity and helping push air out of the lungs. The diaphragm works together with the rib cage and intercostal muscles to facilitate smooth breathing. The movement of the diaphragm is controlled by the phrenic nerve, and its coordinated actions are essential for effective oxygen intake and carbon dioxide removal.