Respiratory System Outcome D1 PDF

OutOutcome D1b: Respiratory System This outcome explains how the human respiratory system exchanges energy and matter with the environment. Air Composition Air is made up of: ○ Nitrogen (78%) ○ Oxygen (21%) ○ Argon (0.9%) ○ Carbon Dioxid...

OutOutcome D1b: Respiratory System This outcome explains how the human respiratory system exchanges energy and matter with the environment. Air Composition Air is made up of: ○ Nitrogen (78%) ○ Oxygen (21%) ○ Argon (0.9%) ○ Carbon Dioxide (0.04%) ○ Trace gases (0.06%) Oxygen is obtained through breathing into the lungs. Lack of oxygen for more than a few minutes can lead to death. Why Breathe? Cells need oxygen for cellular respiration. Cellular respiration produces carbon dioxide as waste. High carbon dioxide levels are harmful to the body. The respiratory system's main function is to take in oxygen and release carbon dioxide. Respiration Requirements Respiration needs a large surface area for efficient gas exchange. A moist environment is needed for oxygen and carbon dioxide to dissolve and diffuse across the membrane. Respiratory Tract: Upper The lungs are the primary organs of respiration, located in the thoracic cavity (chest cavity). The airway is called the respiratory tract, divided into upper and lower sections. The nasal passages warm, moisten, and clean incoming air. Ciliated cells within move foreign particles out of the respiratory tract. Turbinate bones increase the surface area of the nasal cavity, aiding in warming and moistening the air, as well as trapping dust particles. Heat from blood vessels in the nasal passages further warms the air. The pharynx is the common passageway for air and food. The epiglottis is a flap of tissue that covers the trachea (windpipe) to prevent food from entering the airways when swallowing. The glottis is the opening to the trachea.  The larynx, or voice box, contains vocal cords that vibrate to produce sound. The pitch of the voice depends on the length of the vocal cords (longer cords = lower pitch, shorter cords = higher pitch). The trachea, or windpipe, carries air to the lungs. It's supported by C-shaped cartilaginous rings to prevent it from collapsing. Respiratory Tract: Lower The bronchi (singular: bronchus) are two branches that extend from the trachea into each lung. They are supported by C-shaped cartilaginous rings for support. The bronchi are lined with cilia and mucous-producing cells. Bronchioles are subdivisions of the bronchi inside each lung, and do not contain cartilage. The lining is also lined with cilia and mucous-producing cells. Alveoli (singular: alveolus) are clusters of tiny air sacs at the ends of terminal bronchioles. They are the site of gas exchange. Each alveolus wall is extremely thin and is surrounded by a network of capillaries. The alveoli have a moist membrane, a large surface area, and thin walls to optimise gas exchange. They are covered in surfactant to prevent the alveoli from collapsing. Lungs are divided into lobes (the right lung has three, and the left lung has two). The pleural membrane is a double membrane that surrounds the lungs, allowing them to expand and contract with the movement of the chest. The diaphragm is a dome-shaped muscle below the lungs that aids in breathing. It works in conjunction with rib muscles to move air in and out of the lungs. Respiration Respiration is the exchange of air between the atmosphere and the lungs. Breathing involves inhalation (inspiration) and exhalation (expiration). Inhalation involves the contraction of intercostal and rib muscles, causing the ribs to move up and out, and the diaphragm to move down. This increases the size and volume of the thoracic cavity, leading to a decrease in air pressure in the lungs. Air moves from the higher pressure atmosphere into the lower pressure lungs. Exhalation involves the relaxation of intercostal and rib muscles, causing the ribs to move down and in, and the diaphragm to move up. This decreases the size and volume of the thoracic cavity, leading to an increase in air pressure in the lungs. Air moves from the higher pressure lungs to the lower pressure atmosphere. Breathing is an active process during inhalation and a passive process during exhalation. Mechanics of Breathing Breathing relies on the movement of gases from areas of high pressure to areas of low pressure. A difference in air pressure is necessary for breathing to occur. Muscles for Breathing The diaphragm is a dome-shaped muscle at the bottom of the thoracic cavity. Intercostal muscles, also called rib muscles, are found between the ribs on the inside surface. Types of Breathing Inhalation, also known as inspiration, is the process of air entering the lungs. Exhalation, also known as expiration, is the process of air exiting the lungs. Inhalation Inhalation is an active process that requires energy. Intercostal and rib muscles contract, moving the ribs up and out. The diaphragm moves down. The size and volume of the thoracic cavity increase. Air moves from higher atmospheric pressure to lower lung pressure; air enters the lungs. Exhalation Exhalation is generally a passive process. Intercostal and rib muscles relax, moving the ribs down and in.  The diaphragm moves up. The size and volume of the thoracic cavity decrease. Air moves from higher lung pressure to lower atmospheric pressure; air leaves the lungs. Stages of Respiration Breathing involves the exchange of air between the atmosphere and the lungs, including inhalation and exhalation. External respiration is the exchange of gases between the air in the alveoli and the blood in the capillaries within the lungs. Oxygen moves from the air to the blood, and carbon dioxide moves from the blood to the air. Internal respiration is the exchange of gases between the blood and the body's cells. Oxygen moves from the blood to the cells, and carbon dioxide moves from the cells to the blood. Cellular respiration is the process where body cells use oxygen to break down nutrients and produce energy. External Respiration External respiration occurs in the lungs where gases are exchanged. Oxygen moves from the high concentration in the air to the low concentration in the blood by diffusion. Carbon dioxide moves from the high concentration in the blood to the low concentration in the air by diffusion. Transport of Oxygen In the blood, nearly 99% of oxygen is carried bound to hemoglobin within red blood cells. A small portion of oxygen remains dissolved in the plasma. Transport of Carbon Dioxide Approximately 23% of carbon dioxide is carried by hemoglobin. About 7% is dissolved in the blood plasma. Approximately 70% is transported as bicarbonate ions. Carbonic acid dissociates into hydrogen ions and bicarbonate ions in red blood cells, then diffuses into the plasma. Internal Respiration Internal respiration occurs in various tissues of the body. Gases are exchanged between the capillaries and the body cells. Oxygen moves from the blood to the body cells by diffusion. Carbon dioxide moves from the cells to the blood by diffusion. Regulation of Breathing Chemoreceptors are specialized sensory cells detecting changes in blood chemistry (like pH from CO2 levels) that can stimulate the medulla oblongata. The medulla oblongata is a part of the brainstem that regulates breathing; it receives input from chemoreceptors and controls breathing rate and depth. The medulla oblongata also regulates other systems like the cardiovascular system. High CO2 levels in the blood stimulate a nerve response to increase breathing movements. Low levels of oxygen also trigger increased breathing. Individuals can consciously override the automatic breathing regulation of the medulla oblongata, but if CO2 levels get too high, automatic controls take over to prevent dangerous conditions. Lung Volume Lung volume, or lung capacity, is the maximum volume of air that can be held in the lungs. The average male adult lung volume is 6 liters, while the average female's is 5.2-4 liters (10-12% smaller). Lung volume is influenced by height and gender, affecting the size of the thoracic cavity and lungs. During quiet breathing, only about 0.5 liters of air are inhaled and exhaled. Spirometer A spirometer measures lung capacity. Different types exist, including wet spirometers, which use a tube connected to an inverted container floating on water. The expelled air displaces water. Spirograph A spirograph represents the amount of air moving in and out of the lungs with each breath. The graph shows the volume of air in the lungs over time. Lung Volume and Breathing Tidal volume is the volume of air breathed in and out in one normal breath. Typically around 0.50 L.  Only about 0.35 L of air reaches the alveoli; the rest fills the trachea, bronchi, and bronchioles. With an average respiratory rate of 12-20 breaths per minute, 4.2-7 L of air is exchanged per minute. Inspiratory reserve volume is the additional volume of air that can be inhaled beyond a normal breath. It involves expanding the lungs, using neck and abdominal muscles along with the diaphragm and intercostal muscles. Expiratory reserve volume is the additional volume of air that can be exhaled beyond a normal breath. Capacity Definitions Inspiratory capacity is the total amount of air that can be inhaled. This is the sum of tidal volume and inspiratory reserve volume. Vital capacity is the total volume of gas that can be moved in and out of the lungs. This is the sum of inspiratory capacity + expiratory reserve volume. Total lung volume is the total amount of gas that can be held in the lungs and is equal to the sum of vital capacity and residual volume. Residual volume is the amount of gas remaining in the lungs and airways after a forced exhalation. This prevents lung collapse (~1L). Factors Affecting Lung Volume Exercise: Extended exercise increases lung capacity and tidal volume. Illness: Illness can decrease vital capacity and tidal volume by affecting the number of alveoli or weakening the breathing muscles. Tidal volume and vital capacity are reduced. Patient Data Analysis A table of patient data, showing tidal volume, vital capacity, and respiratory rates, is included and used to answer questions related to a long-distance runner or someone with a respiratory disorder. Key differences between tidal volume and vital capacity include that tidal volume describes regular breathing; vital capacity shows maximum air intake/exhale. Based on the data, patient #5 is likely a long-distance runner, having the largest vital capacity and a lower respiratory rate. Patient #3 is potentially suffering from a respiratory disorder – they show a lower than average tidal volume with a higher than average respiratory rate. Respiratory Health The respiratory system connects the body's internal environment to the external environment, like the digestive system. The health of the respiratory system depends on the quality of both the internal and external environments. Lifestyle choices and external environmental changes affect how the respiratory system functions. Upper Respiratory Tract Infections Common causes are viruses or bacteria. Bacterial infections require antibiotics. Infections affect structures in the upper respiratory tract (nasal passages and trachea). Respiratory tract infections are usually short-term and do not block breathing. Tonsillitis Tonsillitis is an infection of the tonsils located in the pharynx. Viral infections are more common than bacterial infections. Frequent tonsillitis may require surgical removal. Tonsils help prevent foreign pathogens from entering the body, but removal does not guarantee a lower infection rate. Laryngitis Laryngitis is the inflammation of the larynx. Inflammation may be caused by a viral infection or allergies, or by straining the voice. This inflammation causes the vocal cords to not vibrate correctly. Symptoms include sore throat and hoarseness. Reduced or complete inability to speak normally may occur. Lower Respiratory Tract Infections These infections are caused by various factors including infections, obstructive pulmonary disorders (OPD), and lung cancer. They affect the bronchi and alveoli. These infections impair breathing and interfere with oxygen delivery to the body's cells. Bronchitis Bronchitis involves inflamed bronchi filled with mucus. Mucus is expelled through coughing. Acute bronchitis is short-term and is usually caused by a bacterial infection, treated with antibiotics. Chronic bronchitis is long-term and is associated with regular exposure to irritants and foreign bodies,. The cilia are damaged and there's no cure, only treatment to reduce symptoms. Smoking is a common cause of chronic bronchitis. Pneumonia Alveoli get inflamed and fill with fluid. This interferes with gas exchange, leading to oxygen starvation. Bacterial pneumonia (Streptococcus pneumoniae) has a preventative vaccine. Viral pneumonia is less severe and can be treated with anti-viral medication. Pleurisy Pleurisy is the inflammation or swelling of the pleura membrane. Causes may be viral, bacterial, blood clots in the lungs, or cancer. Symptoms include sharp stabbing chest pain concentrated to a specific area. Treatment focuses on addressing the underlying cause of the swelling and irritation. Emphysema Alveolar walls weaken and lose elasticity. This reduces the surface area for gas exchange. This leads to oxygen shortage requiring oxygen tanks for breathing. Emphysema is permanently caused by smoking. Cystic Fibrosis It's a genetic condition that affects the lungs, making the mucus lining thick and sticky. Thick mucus traps pathogens, causing frequent lung infections. Treatment involves mucus-thinning medications and antibiotics. Life expectancy is less than 45 years. Asthma Asthma is a chronic inflammatory condition affecting bronchi and bronchioles. Asthma causes breathing difficulties due to reduced airflow. Asthma attacks are triggered by various factors (allergens, pollutants, exercise, etc.).  Inhalers are used to reduce airway inflammation and relax the bronchioles. Lung Cancer Lung cancer involves uncontrollable growth of abnormal cells in the lungs. It is a leading cause of death in men and women globally. Malignant tumors called carcinomas and tumors can impede airway access leading to breathing issues. Smoking is a significant risk factor for lung cancer. Vaping Vaping is a delivery system comparable to a nebulizer. Instead of delivering medication, vaping delivers potentially harmful chemicals. E-cigarettes' liquid mix components include flavorings or various additives and nicotine/THC. Exposure to chemicals in e-liquids might lead to lung inflammation, damage, or cancer. Vaping has been also linked to a range of respiratory problems including chronic lung conditions.