Respiratory System PDF

Section 11.1: The Respiratory System The Respiratory System The respiratory system is responsible for the intake of oxygen and the expulsion of carbon dioxide from the body. It includes the following major components: Upper Respiratory Tract 1. Nose and Nasal...

Section 11.1: The Respiratory System The Respiratory System The respiratory system is responsible for the intake of oxygen and the expulsion of carbon dioxide from the body. It includes the following major components: Upper Respiratory Tract 1. Nose and Nasal Cavity a. Function: The primary entry point for air. The nose filters, warms, and moistens the air before it enters the lungs. b. Details: Hairs and mucus in the nasal cavity trap dust, pollen, and other particles. 2. Pharynx (Throat) a. Function: Serves as a passageway for air from the nasal cavity to the larynx and for food from the mouth to the  esophagus. b. Details: Divided into three regions - nasopharynx, oropharynx, and laryngophar- ynx. 3. Larynx (Voice Box) a. Function: Connects the pharynx to the trachea and houses the vocal cords, which produce sound. b. Details: Contains the epiglottis, which prevents food from entering the trachea during swallowing. Lower Respiratory Tract 4. Trachea (Windpipe) a. Function: A tube that conducts air from the larynx into the bronchi.  b. Details: Lined with ciliated epithelium and mucus to trap particles and move them away from the lungs. 5. Bronchi a. Function: The trachea divides into two main bronchi (left and right) that enter the lungs and branch into smaller bronchi. b. Details: The bronchi continue to branch into smaller and smaller tubes called bronchioles. 6. Bronchioles a. Function: Smaller airways that lead from the bronchi to the alveoli. b. Details: Control the  flow of air in the lungs and play a key role in regulating airflow resistance. 7. Alveoli a. Function: Tiny air sacs where gas exchange occurs. Oxygen from inhaled air diffuses into the blood, and carbon dioxide diffuses from the blood into the alveoli to be exhaled. b. Details: Surrounded by capillaries and have thin walls to facilitate gas exchange. 8. Lungs a. Function: Main organs of the respiratory system where gas exchange occurs. b. Details:  The right lung has three lobes, and the left lung has two lobes to accommo- date the heart. 9. Diaphragm a. Function: A dome-shaped muscle that contracts to allow inhalation by increasing the thoracic cavity volume, and relaxes for exhalation by decreasing thoracic cavity volume. b. Details: Separates the thoracic cavity from the abdominal cavity. Additional Structures and Functions 10. Pleura a. Function: A double- layered membrane  surrounding each lung and lining the thoracic cavity. b. Details: The pleura produces pleural fluid to reduce friction during breathing. 11. Intercostal Muscles a. Function: Muscles located between the ribs that assist with breathing by expanding and contracting the chest cavity. b. Details: External intercostals help with inhalation, while internal intercostals assist with exhalation. 12. Epiglottis a. Function: A flap of tissue  that covers the trachea during swallowing to prevent food from entering the airway. b. Details: Automatically opens and closes as needed. The Process of Breathing · Inhalation (Inspiration): o The diaphragm contracts and moves downward. o The external intercostal muscles contract, lifting the rib cage. o These actions increase the volume of the thoracic cavity and decrease the pressure inside the lungs, allowing air to flow in. · Exhalation (Expiration):  o The diaphragm relaxes and moves upward. o The internal intercostal muscles may contract to pull the rib cage downward. o These actions decrease the volume of the thoracic cavity and increase the pressure inside the lungs, pushing air out. Gas Exchange · External Respiration: o Occurs in the alveoli where oxygen diffuses from the air into the blood, and carbon dioxide diffuses from the blood into the alveoli to be exhaled. · Internal  Respiration: o Occurs at the systemic capillaries where oxygen diffuses from the blood into the body tissues, and carbon dioxide diffuses from the tissues into the blood. Transport of Gases · Oxygen Transport: o Most oxygen is transported by binding to hemoglobin in red blood cells, forming oxyhemoglo- bin. · Carbon Dioxide Transport: o Carbon dioxide is transported in three ways: dissolved in plasma, bound to hemoglobin (forming carbaminohe- moglobin), and as  bicarbonate ions (HCO3-) in the plasma. Respiratory Regulation · Respiratory Center: o Located in the brainstem (medulla oblongata and pons), it controls the rate and depth of breathing. · Chemoreceptors: o Located in the carotid and aortic bodies, they detect changes in blood pH, CO2, and O2 levels and send signals to the respiratory center to adjust breathing. 1. Question: What are the main components of the respiratory system? Answer: The main components are the nose, pharynx, larynx, trachea, bronchi, bronchioles, alveoli, lungs, and diaphragm. 2. Question: Describe the function of the alveoli. Answer: The alveoli are tiny air sacs where gas exchange occurs. Oxygen from inhaled air diffuses into the blood, and carbon dioxide from the blood diffuses into the alveoli to be exhaled. 3. Question: What is the role of the diaphragm in breathing? Answer: The diaphragm contracts during inhalation, increasing thoracic volume and allowing air to enter the lungs. It relaxes during exhalation, decreasing thoracic volume and pushing air out of the lungs. 4. Question: Differentiate between the upper and lower respiratory tracts. Answer: The upper respiratory tract includes the nose, nasal cavity, pharynx, and larynx, responsible for filtering, warming, and moistening air. The lower respiratory tract includes the trachea, bronchi, bronchioles, and alveoli, responsible for conducting air to the lungs and gas exchange. You've covered most of the essential parts and functions of the respiratory system comprehensively. However, there are a few additional details and structures that might be worth mentioning for a more thorough understanding: Additional Details and Structures 1. Cilia and Mucus a. Cilia: Tiny hair-like structures lining the respiratory  tract, particularly in the nasal cavity, trachea, and bronchi. They move rhythmically to sweep mucus and trapped particles out of the airways. b. Mucus: Produced by goblet cells and mucous glands in the respiratory tract. It traps dust, microbes, and other particles, preventing them from reaching the lungs. 2. Sinuses a. Function: Air-filled spaces in the bones of the face (frontal, maxillary, ethmoidal, and sphenoidal sinuses).  They help lighten the weight of the skull, warm and moisten the air, and enhance voice resonance. b. Details: The sinuses are connected to the nasal cavity and contribute to the humidifica- tion and filtration of inhaled air. 3. Laryngeal Cartilages a. Thyroid Cartilage: The largest cartilage of the larynx, commonly known as the Adam's apple. b. Cricoid Cartilage: A ring-shaped structure below the thyroid cartilage, providing support and  structure to the larynx. c. Arytenoid Cartilages: Paired cartilages that anchor the vocal cords. 4. Respiratory Membrane a. Function: The thin barrier between the alveolar air and the blood in the capillaries where gas exchange occurs. b. Details: Composed of the alveolar epithelial cells, the capillary endothelial cells, and their fused basement membranes. 5. Surfactant a. Function: A lipoprotein substance secreted by  type II alveolar cells that reduces surface tension in the alveoli, preventing their collapse and making breathing easier. b. Details: Essential for maintaining alveolar stability and function, especially important in preventing respiratory distress syndrome in newborns. 6. Respiratory Volumes and Capacities a. Tidal Volume (TV): The amount of air inhaled or exhaled during normal breathing. b. Inspiratory Reserve Volume (IRV): The additional air that can be  inhaled after a normal inhalation. c. Expiratory Reserve Volume (ERV): The additional air that can be exhaled after a normal exhalation. d. Residual Volume (RV): The air remaining in the lungs after a maximal exhalation. e. Vital Capacity (VC): The total amount of air that can be exhaled after a maximal inhalation (TV + IRV + ERV). f. Total Lung Capacity (TLC): The total volume of the lungs (VC + RV). 7. Alveolar Macrophages a.  Function: Immune cells that reside in the alveoli and engulf and digest microbes, dust, and other particles that have reached the alveolar spaces. b. Details: Play a crucial role in protecting the lungs from infection and clearing debris. 8. Respiratory Centers in the Brainstem a. Medulla Oblongata: Contains the dorsal respiratory group (DRG) and the ventral respiratory group (VRG), which control the basic rhythm of breathing. b. Pons: Contains the pneumotaxic  center and the apneustic center, which modulate the activity of the medullary respiratory centers to smooth the transitions between inhalation and exhalation. Physiology and Pathophysiology 1. Ventilation- Perfusion Ratio (V/ Q Ratio) a. Function: The ratio of the amount of air reaching the alveoli (ventilation) to the blood flow in the pulmonary capillaries (perfusion). b. Details: Optimal gas exchange occurs when ventilation and perfusion are matched. Imbalances can lead to respiratory issues like  hypoxia or hypercapnia. 2. Hypoxia and Hypercapnia a. Hypoxia: A condition where there is insufficient oxygen in the tissues. b. Hypercapnia: An excess of carbon dioxide in the bloodstream, often due to inadequate respiration. 3. Chronic Obstructive Pulmonary Disease (COPD) a. Details: A group of lung diseases, including emphysema and chronic bronchitis, characterized by obstructed airflow and breathing difficulties. 4. Asthma a. Details: A chronic condition characterized  by episodes of airway constriction, inflammation, and increased mucus production, leading to breathing difficulties. 5. Pulmonary Fibrosis a. Details: A condition where lung tissue becomes scarred and stiff, making it difficult to breathe and for oxygen to enter the bloodstream. Section 11.2: Mechanism of Breathing 5. Question: What happens to the thoracic cavity during inhalation? Answer: During inhalation, the diaphragm contracts and the intercostal muscles lift the rib cage, increasing the thoracic cavity volume and causing air to flow into the lungs. 6. Question: Explain the role of the respiratory centre in the brainstem. Answer: The respiratory centre in the brainstem (medulla oblongata) controls the rate and depth of breathing by sending signals to the respiratory muscles. 7. Question: How do chemoreceptors regulate breathing? Answer: Chemoreceptors in the carotid and aortic bodies detect changes in blood pH, CO2, and O2 levels and send signals to the respiratory centre to adjust breathing rate and depth. 8. Question: What is vital capacity, and how is it calculated? Answer: Vital capacity is the total amount of air exhaled after a maximum inhalation. It is calculated as the sum of tidal volume (TV), inspiratory reserve volume (IRV), and expiratory reserve volume (ERV). Section 11.3: Gas Exchange in the Body 9. Question: Describe the process of external respiration. Answer: External respiration occurs in the alveoli, where oxygen from inhaled air diffuses into the blood in the pulmonary capillaries, and carbon dioxide diffuses from the blood into the alveoli to be exhaled. 10. Question: How is oxygen transported in the blood? Answer: Oxygen is primarily transported in the blood by binding to hemoglobin in red blood cells, forming oxyhemoglobin. 11. Question: What are the three main forms of carbon dioxide transport in the blood? Answer: Carbon dioxide is transported as bicarbonate ions (HCO3-), dissolved in plasma, and bound to hemoglobin (forming carbaminohemoglobin). 12. Question: What enzyme catalyzes the conversion of carbon dioxide and water to carbonic acid? Answer: The enzyme carbonic anhydrase catalyzes this conversion. Section 11.4: Disorders of the Respiratory System 13. Question: What are the primary symptoms of asthma? Answer: The primary symptoms of asthma include wheezing, shortness of breath, chest tightness, and coughing. 14. Question: How does smoking contribute to chronic bronchitis and emphysema? Answer: Smoking irritates and inflames the airways, leading to chronic bronchitis, and damages the alveoli, reducing their elasticity and surface area, leading to emphysema. 15. Question: Describe the genetic basis and respiratory effects of cystic fibrosis. Answer: Cystic fibrosis is a genetic disorder caused by mutations in the CFTR gene, leading to thick, sticky mucus production that clogs airways and affects lung function. 16. Question: What are the main differences between acute bronchitis and chronic bronchitis? Answer: Acute bronchitis is a short- term inflammation of the bronchi, usually caused by infection, while chronic bronchitis is a long-term condition often caused by smoking, characterized by persistent cough and mucus production. 17. Question: Explain how pneumonia affects the lungs. Answer: Pneumonia is an infection that inflames the air sacs (alveoli) in one or both lungs, causing them to fill with fluid or pus, leading to cough, fever, chills, and difficulty breathing. 18. Question: What is pulmonary fibrosis, and how does it affect lung function? Answer: Pulmonary fibrosis is the formation of scar tissue in the lungs, which reduces their elasticity and impairs gas exchange, leading to breathing difficulties and reduced oxygen levels in the blood. 19. Question: How does lung cancer typically develop and what are its main risk factors? Answer: Lung cancer typically develops due to uncontrolled cell growth in lung tissue, with main risk factors including smoking, exposure to secondhand smoke, and exposure to certain toxins and pollutants. Additional Practice Questions 20. Question: What is the role of the pharynx in the respiratory system? Answer: The pharynx serves as a passageway for air from the nasal cavity to the larynx and for food from the mouth to the esophagus. 21. Question: How do vocal cords produce sound? Answer: Vocal cords produce sound by vibrating as air passes through them when expelled from the lungs during exhalation. The tension and length of the vocal cords can be adjusted to change pitch and tone. 22. Question: What happens to the rib cage during exhalation? Answer: During exhalation, the intercostal muscles relax, causing the rib cage to move downward and inward, decreasing thoracic volume and pushing air out of the lungs. 23. Question: Define tidal volume and its significance in respiration. Answer: Tidal volume (TV) is the amount of air inhaled or exhaled during a normal breath. It is significant because it reflects the basic respiratory function and can be used to assess lung health. 24. Question: What causes laryngitis, and what are its symptoms? Answer: Laryngitis is caused by inflammation of the larynx, often due to viral infections, overuse of the voice, or irritants. Symptoms include hoarseness, loss of voice, and throat pain. 25. Question: How does the body adjust breathing in response to high levels of carbon dioxide in the blood? Answer: High levels of carbon dioxide in the blood are detected by chemoreceptors, which send signals to the respiratory centre to increase the rate and depth of breathing, allowing more CO2 to be exhaled and reducing blood CO2 levels. 26. Question: What is the significance of the bicarbonate ion (HCO3-) in carbon dioxide transport? Answer: The bicarbonate ion is significant because it is the primary form in which carbon dioxide is transported in the blood. It helps maintain blood pH balance by acting as a buffer. 27. Question: Describe the process of internal respiration. Answer: Internal respiration is the exchange of gases between the blood in systemic capillaries and body tissues. Oxygen diffuses from the blood into the tissues, while carbon dioxide diffuses from the tissues into the blood. 28. Question: What are the symptoms and potential complications of untreated sinusitis? Answer: Symptoms of sinusitis include nasal congestion, facial pain, pressure, and discharge. Potential complications include chronic sinusitis, spread of infection to nearby structures (such as the eyes or brain), and reduced quality of life due to persistent symptoms. 29. Question: Explain how pulmonary tuberculosis is diagnosed and treated. Answer: Pulmonary tuberculosis is diagnosed through skin tests (e.g., Mantoux test), blood tests, chest X- rays, and sputum analysis. Treatment involves a prolonged course of multiple antibiotics to eradicate the Mycobacterium tuberculosis bacteria. 30. Question: What lifestyle changes can help manage chronic bronchitis? Answer: Lifestyle changes that can help manage chronic bronchitis include quitting smoking, avoiding lung irritants (such as pollution and chemical fumes), staying hydrated, and engaging in regular physical activity to strengthen respiratory muscles. Chapter Review Questions Chapter 11.1: The Respiratory System Key Terms 1. Question: What are the main functions of the respiratory system?. Answer: The main functions are to supply the body with oxygen and remove carbon dioxide. 3. Question: What structures make up the upper respiratory tract? Answer: The upper respiratory tract includes the nose, pharynx, and larynx. 4. Question: What structures make up the lower respiratory tract? Answer: The lower respiratory tract includes the trachea, bronchi, bronchioles, and lungs. 5. Question: What is the function of the larynx? Answer: The larynx houses the vocal cords and is responsible for sound production. 6. Question: What is the role of the alveoli? Answer: Alveoli are tiny air sacs where gas exchange occurs between the air and the blood. Key Concepts 1. Question:  Describe the pathway of air from the nose to the alveoli. Answer: Air enters through the nose, passes through the pharynx and larynx, travels down the trachea, enters the bronchi Scene 1: Lungs (Alveoli) Props: Small pieces of paper labeled Water (H₂O), Carbon Dioxide (CO₂), Oxygen (O₂), Bicarbonate Ion (HCO₃⁻), Hydrogen Ion (H⁺), Hemoglobin, Red Blood Cell. Narrator: "Welcome to the journey of gas exchange and transport in the body. We begin our journey in the lungs, specifically in the alveoli, where gas exchange takes place." Action: 1. Place the pieces of paper labeled Oxygen (O₂) (two of them) into the alveoli section. Narrator: "Here in the alveoli, oxygen (O₂) from the inhaled air diffuses into the blood vessels." 2. Place the piece of paper labeled Red Blood Cell and two Hemoglobin into the blood vessel section adjacent to the alveoli. Narrator: "Red blood cells, containing hemoglobin, are ready to pick up the oxygen." 3. Move the Oxygen (O₂) papers from the alveoli to the Red Blood Cell. Narrator: "Oxygen (O₂) binds to hemoglobin in the red blood cells, forming oxyhemoglobin. Now, the oxygenated blood is ready to travel through the body." Scene 2: Blood Vessel (Arterial Blood) Narrator: "Our journey continues through the blood vessels as the oxygenated blood travels towards the tissues." Action: 1. Move the Red Blood Cell (with Oxygen (O₂) papers) through the blood vessel section. Narrator: "The red blood cells carry oxygen (O₂) through the arteries to various tissues in the body." Scene 3: Tissue (Toes) Narrator: "Now we arrive at the tissues, such as the toes, where oxygen (O₂) is delivered, and carbon dioxide (CO₂) is picked up." Action: 1. Move the Red Blood Cell (with Oxygen (O₂) papers) to the tissue section (toes). Narrator: "In the tissues, oxygen (O₂) is released from the red blood cells and diffuses into the cells for use in metabolism." 2. Remove the Oxygen (O₂) papers from the Red Blood Cell and place them into the tissue (toes) section. Narrator: "Oxygen (O₂) is now being used by the cells to produce energy, resulting in the production of carbon dioxide (CO₂) as a waste product." 3. Place the Carbon Dioxide (CO₂) paper into the tissue (toes) section. Narrator: "Carbon dioxide (CO₂) diffuses from the tissues into the blood vessels." 4. Move the Carbon Dioxide (CO₂) paper from the tissue (toes) section to the Red Blood Cell. 1. Pay attention to the words in bold letters. Circle the correct word that makes the sentence make sense. During external respiration in the lungs, oxygen/carbon dioxide leaves the blood and oxygen/carbon dioxide enters the blood. During internal respiration in the tissues, oxygen/carbon dioxide leaves the blood and oxygen/carbon dioxide enters the blood 2. Fill in the blanks with the correct words (Words are used once only and there will be some left over) carbonic acid, basie, warm, tower, acidie, carbaminahemeglobin (HbCOz), oxyhemoglobin (HbOz) , carbonhemoglobin, bicarbonate ions (HCO3), reduced Hemoglobin (HHb), carbonic anhydrase, oxygen, carbon dioxide. Most carbon dioxide is carried in the plasma as Dicaponarion. As free COz starts to diffuse out of and torme by izame came any rapen orel die cels, speeds the breakdown of carbonic. Hemoglobin has a higher affinity for oxygen at lower temperatures and baste _conditions. It becomes oxyhemaglobin _ in the lungs during external respiration. 3. In internal respiration, involving the exchange between tissues and capillaries, the warm _ temperature and acidic condition allows hemoglobin to give up the oxygen and to take up carbon dioxide that has diffused into the capillaries from the tissues. This molecule is called Car hunainahemog obn 4. The remaining COz combines with water to form Carbonic acid _, which dissociates to hydrogen ions and bicarbonate ions. Bicarbonate ions diffuse out into the plasma and the globin portion of the hemoglobin combines with excess H+ and becomes reduced hemoglobin 6 characteristics 1. S p h e r i c a l i n s h a p e - l a r g e s u r f a c e a r e a f o r g a s e x c h a n g e. T h e y v a r y i n s i z e. 2. N u m e r o u s - h e l p s w i t h t h e e f f i c i e n c y o f g a s e x c h a n g e. T h e r e a r e a b o u t 3 0 0 m i l l i o n a l v e o l i i n t h e l u n g s. 3. W e l l v a s c u l a r i z e d - h e l p s t o p i c k u p o x y g e n a n d c a r r y i t t o t h e b l o o d c a p i l l a r i e s t h a t s u r r o u n d t h e m , d u r i n g i n h a l a t i o n , o x y g e n m o v e s f r o m t h e l u n g s t o t h e b l o o d c a p i l l a r i e s t h a t s u r r o u n d t h e m , d u r i n g i n h a l a t i o n , o x y g e n m o v e s f r o m t h e l u n g s t o t h e b l o o d c a p i l l a r i e s t h a t s u r r o u n d t h e m , d u r i n g i n h a l a t i o n , o x y g e n m o v e s f r o m t h e l u n g s t o t h e b l o o d c a p i l l a r i e s t h a t s u r r o u n d t h e m. 4. C o a t e d w i t h a l v e o l a r f l u i d t o r e d u c e s u r f a c e t e n s i o n w i t h o u t a l v e o l a r f l u i d t o r e d u c e s u r f a c e t e n s i o n , t h e a l v e o l i w o u l d c o l l a p s e , a n d t h e a l v e o l i w o u l d c o l l a p s e , a n d t h e s u r f a c e t e n s i o n o f w a t e r w o u l d c o l l a p s e , a n d t h e s u r f a c e t e n s i o n o f w a t e r w o u l d c o l l a p s e , a n d t h e s u r f a c e t e n s i o n o f w a t e r w o u l d c o l l a p s e. 5. C o n t a i n s t r e t c h r e c e p t o r s t o h e l p p r e v e n t o v e r - i n f l a t i o n o f t h e l u n g s. T h e y h e l p t o r e g u l a t e t h e i n f l a t i o n o f t h e l u n g s. 6. T h i n w a l l e d - h e l p s g a s e x c h a n g e f o r e f f i c i e n t g a s e x c h a n g e f o r e f f i c i e n t g a s e x c h a n g e.