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Chapter 24 - The respiratory system. After completing chapter 24, you will be able to: Explain the functions of the respiratory system, explain the difference between internal respiration and external respiration, describe how the larynx produces voice sounds, list the structures contained within the lungs, describe the coverings of the lungs and chest cavity,...
CHAPTER 24 The Respiratory System © 2011 The McGraw-Hill Companies, Inc All rights reserved 242 Learning Outcomes 24.1 Explain the functions of the respiratory system 24.2 Explain the difference between internal respiration and external respiration 24.3 Describe how the larynx produces voice sounds 24.4 List the structures contained within the lungs 24.5 Describe the coverings of the lungs and chest cavity © 2011 The McGraw-Hill Companies, Inc All rights reserved 243 Learning Outcomes (cont.) 24.6 Describe the events that lead to the inspiration and expiration of air 24.7 Explain how the brain controls breathing and how normal breathing patterns can be disrupted 24.8 Describe how oxygen is transported from the lungs to body cells © 2011 The McGraw-Hill Companies, Inc All rights reserved 244 Learning Outcomes (cont.) 24.9 Describe how carbon dioxide is transported from body cells to the lungs 24.10List and explain various respiratory volumes and tell how they are used to diagnose respiratory problems 24.11Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the respiratory system © 2011 The McGraw-Hill Companies, Inc All rights reserved 245 Introduction • Function – Move air in and out of lungs (ventilation) – Delivers oxygen (O2) – Removes carbon dioxide (CO2) CO2 • External respiration O2 – Occurs in the lungs • Internal respiration – Occurs in the hemoglobin O2 Lungs CO2 CO2 O2 © 2011 The McGraw-Hill Companies, Inc All rights reserved 246 Organs of the Respiratory System Nose Pharynx Larynx Trachea Bronchial tree Lungs © 2011 The McGraw-Hill Companies, Inc All rights reserved 247 Nasal Cavity • Nasal septum divides the cavity into right and left portions – Nares – openings of the nose • Nasal conchae extend from walls of nasal cavity • Mucous membrane warms and moistens the air • Cilia help eliminate particles © 2011 The McGraw-Hill Companies, Inc All rights reserved 248 Paranasal Sinuses • Air-filled spaces within the skull bones – Open into the nasal cavity • Reduce the weight of the skull • Equalize pressure • Give the voice its certain tone • Skull bones with sinuses include: – – – – Frontal Sphenoid Ethmoid Maxillae bones © 2011 The McGraw-Hill Companies, Inc All rights reserved 249 Pharynx and Larynx • Pharynx – Serves both the respiratory and digestive systems • Larynx – Also called the “voice box” – Moves air in and out of the trachea and produces voice – Composed of three cartilages: • Thyroid cartilage • Epiglottic cartilage • Cricoid cartilage © 2011 The McGraw-Hill Companies, Inc All rights reserved 2410 Vocal Cords • Stretched between the thyroid cartilage and the cricoid cartilage • Upper – false cords • Lower – true vocal cords • Glottis – the opening between the vocal cords • Stretch = pitch of voice Posterior Portion of Tongue False Vocal Cords Glottis True Vocal Cords © 2011 The McGraw-Hill Companies, Inc All rights reserved 2431 Common Diseases and Disorders (cont.) Disease Description Chronic obstructive pulmonary disease (COPD) A group of lung disorders that limit airflow to lungs and usually cause enlargement of the alveoli Emphysema A chronic condition associated with smoking that damages the alveoli; one type of COPD Influenza A viral disease that attacks the respiratory system; commonly called the flu © 2011 The McGraw-Hill Companies, Inc All rights reserved 2432 Common Diseases and Disorders (cont.) Disease Description Laryngitis An acute inflammation of the larynx causing hoarseness (dysphonia) Legionnaire’s disease Acute bacterial pneumonia caused by Legionnaire bacteria that usually grows in the standing water of air conditioning systems Lung cancer Cancer closely associated with smoking and exposure to second-hand smoke; four types of lung cancers Pleural effusion A buildup of fluid in the pleural cavity © 2011 The McGraw-Hill Companies, Inc All rights reserved 2433 Common Diseases and Disorders (cont.) Disease Description Pleuritis/Pleurisy Inflammation of the membranes that cover the lungs, known as pleura Pneumoconiosis Lung diseases that result from years environmental or occupational exposure to different types of dust; three types Pneumonia/ Pneumonitis An inflammation of the lungs that is most often caused by a bacterial, viral, or fungal infection © 2011 The McGraw-Hill Companies, Inc All rights reserved 2434 Common Diseases and Disorders (cont.) Disease Description Pneumothorax A collection of air in the chest around the lungs, which may cause atelectasis Pulmonary edema A condition in which fluids fill spaces within the lungs, making it very difficult for the lungs to oxygenate the blood Pulmonary embolism A blood clot (embolism) that travels usually from the legs and blocks an artery in the lungs © 2011 The McGraw-Hill Companies, Inc All rights reserved 2435 Common Diseases and Disorders (cont.) Disease Description Respiratory distress syndrome (RDS) Syndrome in which a lack of surfactant in the lungs allows the alveoli to collapse on exhalation, resulting in poor oxygenation Severe acute respiratory syndrome (SARS) A viral respiratory disease that is very contagious and sometimes fatal Sinusitis An inflammation of the membranes lining the sinuses of the skull © 2011 The McGraw-Hill Companies, Inc All rights reserved 2436 Common Diseases and Disorders (cont.) Disease Description Sudden infant death syndrome (SIDS) A syndrome without characteristic signs or symptoms; usually a baby with this disorder simply goes to sleep and never wakes up Tuberculosis Primarily a respiratory disease caused by various strains of the bacterium Mycobacterium tuberculosis Upper respiratory Coryza, or the common cold (tract) infection (URI) © 2011 The McGraw-Hill Companies, Inc All rights reserved 2437 Apply Your Knowledge The medical assistant working for a general practitioner is taking the medical history of a new patient The patient states, “Even after sleeping to hours, I still feel really tired.” The patient’s spouse states, “Well, you sure snore loud, as if the sleep is so good.” Which of the following is a possible cause for the excessive fatigue? ANSWER: a Sleep apnea b Depression c Tuberculosis © 2011 The McGraw-Hill Companies, Inc All rights reserved 2438 In Summary 24.1 The function of the respiratory system is to move air in and out of the lungs in a process known as ventilation, respiration, or breathing 24.2 The exchange of oxygen and carbon dioxide in the lungs is called external respiration The same exchange within the hemoglobin of red blood cells is internal respiration 24.3 The larynx contains the vocal cords, which stretch between the thyroid and cricoid cartilages The muscles of the lower (true) vocal cords stretch and relax them to produce different sounds © 2011 The McGraw-Hill Companies, Inc All rights reserved 2439 In Summary (cont.) 24.4 The lungs contain connective tissue, the bronchial tree, nerves, lymphatic vessels, and blood vessels The left lung consists of two lobes (upper and lower), and the right lung consists of three lobes (upper, middle, and lower) Within each lung are the primary, secondary, and tertiary branches of the bronchi, the bronchioles, and the alveoli 24.5 The lungs are covered by, and the chest cavity is lined with, the pleura The outer membrane is the parietal pleura and the inner membrane is the visceral pleura © 2011 The McGraw-Hill Companies, Inc All rights reserved 2440 In Summary (cont.) 24.6 During inspiration, the diaphragm contracts and the intercostal muscles raise the ribs, increasing the space in the thoracic cavity This decreases the pressure within the cavity so that the air outside the body passively flows into the thoracic cavity During expiration, the diaphragm relaxes, pushing up into the thoracic cavity, and the intercostal muscles lower the ribs, forcing the air to flow out of the body © 2011 The McGraw-Hill Companies, Inc All rights reserved 2441 In Summary (cont.) 24.7 Breathing is controlled by the respiratory center of the brain located in the pons and medulla oblongata Carbon dioxide levels and pH levels of the blood also affect breathing Everyday situations such as coughing, sneezing, laughing, crying, hiccups, yawning, and speaking also alter breathing patterns 24.8 Most of the oxygen in the bloodstream binds to the hemoglobin within red blood cells, resulting in oxyhemoglobin, although a small amount does not bind to hemoglobin and remains dissolved in the plasma © 2011 The McGraw-Hill Companies, Inc All rights reserved 2442 In Summary (cont.) 24.9 Carbon dioxide binds to hemoglobin, resulting in carboxyhemoglobin Most of the carbon dioxide that enters the body reacts with water in blood and cerebral spinal fluid to form carbonic acid As carbonic acid ionizes, it releases hydrogen and bicarbonate ions, which attach to hemoglobin making its way back to the lungs to be exhaled © 2011 The McGraw-Hill Companies, Inc All rights reserved 2443 In Summary (cont.) 24.10 Respiratory volumes are measured to check the health of the respiratory system The volumes are listed here and the normal capacities are found in the chapter: tidal volume, inspiratory and expiratory reserve volumes, residual volume, inspiratory capacity, functional residual capacity, vital capacity, and total lung capacity © 2011 The McGraw-Hill Companies, Inc All rights reserved 2444 In Summary (cont.) 24.11 The diseases and disorders of the respiratory system are many and varied, as are the causes and treatments of these diseases Many of the more common respiratory disorders, with their individual causes and treatments, are discussed in detail in the Pathophysiology section of this chapter © 2011 The McGraw-Hill Companies, Inc All rights reserved 2445 End of Chapter 24 The air of ideas is the only air worth breathing ~Edith Wharton © 2011 The McGraw-Hill Companies, Inc All rights reserved ... CO2 levels in the blood – Medulla oblongata – controls rhythm and depth of breathing – pH of the blood – Pons – controls the rate of breathing – Inflation reflex – Fear and pain © 2011 The McGraw-Hill... • Skull bones with sinuses include: – – – – Frontal Sphenoid Ethmoid Maxillae bones © 2011 The McGraw-Hill Companies, Inc All rights reserved 24 9 Pharynx and Larynx • Pharynx – Serves both... Inc All rights reserved 24 18 The Mechanisms of Breathing (cont.) • Causes of altered breathing patterns – Coughing – Sneezing – Laughing – Crying – Hiccups – Yawning – Speaking © 2011 The McGraw-Hill