Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
PowerPoint® Lecture Slides prepared by Barbara Heard, Atlantic Cape Community College CHAPTER 22 The Respiratory System: Part A © Annie Leibovitz/Contact Press Images © 2013 Pearson Education, Inc. © 2013 Pearson Education, Inc. The Respiratory System • Major function-respiration – Supply body with O2 for cellular respiration; dispose of CO2, a waste product of cellular respiration – Its four processes involve both respiratory and circulatory systems • Also functions in olfaction and speech © 2013 Pearson Education, Inc. Processes of Respiration • Pulmonary ventilation (breathing)movement of air into and out of lungs • External respiration-O2 and CO2 exchange between lungs and blood • Transport-O2 and CO2 in blood • Internal respiration-O2 and CO2 exchange between systemic blood vessels and tissues © 2013 Pearson Education, Inc. Respiratory system Circulatory system Respiratory System: Functional Anatomy • Major organs – Nose, nasal cavity, and paranasal sinuses – Pharynx – Larynx – Trachea – Bronchi and their branches – Lungs and alveoli © 2013 Pearson Education, Inc. Figure 22.1 The major respiratory organs in relation to surrounding structures. Nasal cavity Oral cavity Nostril Pharynx Larynx Trachea Carina of trachea Right main (primary) bronchus Right lung Left main (primary) bronchus Left lung Diaphragm © 2013 Pearson Education, Inc. The Nose • Functions – Provides an airway for respiration – Moistens and warms entering air – Filters and cleans inspired air – Serves as resonating chamber for speech – Houses olfactory receptors © 2013 Pearson Education, Inc. Nasal Cavity • Nasal vestibule-nasal cavity superior to nostrils – Vibrissae (hairs) filter coarse particles from inspired air • Rest of nasal cavity lined with mucous membranes – Olfactory mucosa – Respiratory mucosa © 2013 Pearson Education, Inc. Nasal Cavity • Respiratory mucosa – Mucous and serous secretions contain lysozyme and defensins – Cilia move contaminated mucus posteriorly to throat © 2013 Pearson Education, Inc. Figure 22.3b The upper respiratory tract. Cribriform plate of ethmoid bone Sphenoidal sinus Frontal sinus Nasal cavity Nasal conchae (superior, middle and inferior) Nasal meatuses (superior, middle, and inferior) Nasal vestibule Posterior nasal aperture Nasopharynx Pharyngeal tonsil Opening of pharyngotympanic tube Uvula Nostril Oropharynx Palatine tonsil Isthmus of the fauces Hard palate Soft palate Tongue Lingual tonsil Laryngopharynx Esophagus Larynx Epiglottis Vestibular fold Thyroid cartilage Vocal fold Cricoid cartilage Trachea Thyroid gland Illustration © 2013 Pearson Education, Inc. Hyoid bone Figure 22.3a The upper respiratory tract. Olfactory nerves Olfactory epithelium Superior nasal concha and superior nasal meatus Mucosa of pharynx Middle nasal concha and middle nasal meatus Tubal tonsil Inferior nasal concha and inferior nasal meatus Pharyngotympanic (auditory) tube Nasopharynx Hard palate Soft palate Uvula Photograph © 2013 Pearson Education, Inc. Functions of the Nasal Mucosa and Conchae • During inhalation, conchae and nasal mucosa – Filter, heat, and moisten air • During exhalation these structures – Reclaim heat and moisture © 2013 Pearson Education, Inc. Paranasal Sinuses • In frontal, sphenoid, ethmoid, and maxillary bones • Lighten skull; secrete mucus; help to warm and moisten air © 2013 Pearson Education, Inc. Homeostatic Imbalance • Rhinitis – Inflammation of nasal mucosa – Nasal mucosa continuous with mucosa of respiratory tract spreads from nose throat chest – Spreads to tear ducts and paranasal sinuses causing • Blocked sinus passageways air absorbed vacuum sinus headache © 2013 Pearson Education, Inc. Pharynx • Muscular tube – Connects nasal cavity and mouth to larynx and esophagus – Composed of skeletal muscle • Three regions – Nasopharynx – Oropharynx – Laryngopharynx © 2013 Pearson Education, Inc. Figure 22.3c The upper respiratory tract. Pharynx Nasopharynx Oropharynx Laryngopharynx Regions of the pharynx © 2013 Pearson Education, Inc. Nasopharynx • Air passageway posterior to nasal cavity • Lining - pseudostratified columnar epithelium • Soft palate and uvula close nasopharynx during swallowing • Pharyngeal tonsil (adenoids) on posterior wall • Pharyngotympanic (auditory) tubes drain and equalize pressure in middle ear; open into lateral walls © 2013 Pearson Education, Inc. Oropharynx • Passageway for food and air from level of soft palate to epiglottis • Lining of stratified squamous epithelium • Isthmus of fauces-opening to oral cavity • Palatine tonsils-in lateral walls of fauces • Lingual tonsil-on posterior surface of tongue © 2013 Pearson Education, Inc. Laryngopharynx • Passageway for food and air • Posterior to upright epiglottis • Extends to larynx, where continuous with esophagus • Lined with stratified squamous epithelium © 2013 Pearson Education, Inc. Figure 22.3b The upper respiratory tract. Cribriform plate of ethmoid bone Sphenoidal sinus Frontal sinus Nasal cavity Nasal conchae (superior, middle and inferior) Nasal meatuses (superior, middle, and inferior) Nasal vestibule Posterior nasal aperture Nasopharynx Pharyngeal tonsil Opening of pharyngotympanic tube Uvula Nostril Oropharynx Palatine tonsil Isthmus of the fauces Hard palate Soft palate Tongue Lingual tonsil Laryngopharynx Esophagus Larynx Epiglottis Vestibular fold Thyroid cartilage Vocal fold Cricoid cartilage Trachea Thyroid gland Illustration © 2013 Pearson Education, Inc. Hyoid bone Larynx • Attaches to hyoid bone; opens into laryngopharynx; continuous with trachea • Functions – Provides patent airway – Routes air and food into proper channels – Voice production • Houses vocal folds © 2013 Pearson Education, Inc. Figure 22.4a The larynx. Epiglottis Thyrohyoid membrane Body of hyoid bone Thyroid cartilage Laryngeal prominence (Adam’s apple) Cricothyroid ligament Cricoid cartilage Cricotracheal ligament Tracheal cartilages Anterior superficial view © 2013 Pearson Education, Inc. Figure 22.4b The larynx. Epiglottis Thyrohyoid membrane Body of hyoid bone Thyrohyoid membrane Cuneiform cartilage Fatty pad Corniculate cartilage Vestibular fold (false vocal cord) Arytenoid cartilage Thyroid cartilage Arytenoid muscles Vocal fold (true vocal cord) Cricoid cartilage Cricothyroid ligament Cricotracheal ligament Tracheal cartilages Sagittal view; anterior surface to the right © 2013 Pearson Education, Inc. Figure 22.4c The larynx. Epiglottis Hyoid bone Thyroid cartilage Lateral thyrohyoid membrane Corniculate cartilage Arytenoid cartilage Glottis Cricoid cartilage Tracheal cartilages Photograph of cartilaginous framework of the larynx, posterior view © 2013 Pearson Education, Inc. Figure 22.4d The larynx. Epiglottis Laryngeal inlet Corniculate cartilage Posterior cricoarytenoid muscle on cricoid cartilage Trachea (d) Photograph of posterior aspect © 2013 Pearson Education, Inc. Figure 22.5 Movements of the vocal folds. Base of tongue Epiglottis Vestibular fold (false vocal cord) Vocal fold (true vocal cord) Glottis Inner lining of trachea Cuneiform cartilage Corniculate cartilage Vocal folds in closed position; closed glottis © 2013 Pearson Education, Inc. Vocal folds in open position; open glottis Trachea • Windpipe–from larynx into mediastinum • Wall composed of three layers – Mucosa-ciliated pseudostratified epithelium with goblet cells – Submucosa-connective tissue with seromucous glands – Adventitia-outermost layer made of connective tissue; encases C-shaped rings of hyaline cartilage © 2013 Pearson Education, Inc. Figure 22.6b Tissue composition of the tracheal wall. Goblet cell Mucosa • Pseudostratified ciliated columnar epithelium • Lamina propria (connective tissue) Submucosa Seromucous gland In submucosa Hyaline cartilage Photomicrograph of the tracheal wall (320x) © 2013 Pearson Education, Inc. Figure 22.6c Tissue composition of the tracheal wall. Scanning electron micrograph of cilia in the trachea (2500x) © 2013 Pearson Education, Inc. Conducting Zone Structures • Trachea right and left main (primary) bronchi © 2013 Pearson Education, Inc. Conducting Zone Structures • Branches become smaller and smaller – Bronchioles-less than 1 mm in diameter – Terminal bronchioles-smallest-less than 0.5 mm diameter © 2013 Pearson Education, Inc. Figure 22.7 Conducting zone passages. Trachea Superior lobe of left lung Left main (primary) bronchus Superior lobe of right lung Lobar (secondary) bronchus Segmental (tertiary) bronchus Middle lobe of right lung Inferior lobe of right lung © 2013 Pearson Education, Inc. Inferior lobe of left lung Conducting Zone Structures • From bronchi through bronchioles, structural changes occur – Cartilage rings become irregular plates; in bronchioles elastic fibers replace cartilage – Epithelium changes from pseudostratified columnar to cuboidal; cilia and goblet cells become sparse – Relative amount of smooth muscle increases • Allows constriction © 2013 Pearson Education, Inc. Respiratory Zone • Begins as terminal bronchioles respiratory bronchioles alveolar ducts alveolar sacs – Alveolar sacs contain clusters of alveoli • ~300 million alveoli make up most of lung volume • Sites of gas exchange © 2013 Pearson Education, Inc. Figure 22.8a Respiratory zone structures. Alveoli Alveolar duct Respiratory bronchioles Terminal bronchiole © 2013 Pearson Education, Inc. Alveolar duct Alveolar sac Figure 22.8b Respiratory zone structures. Respiratory bronchiole Alveolar duct Alveoli Alveolar sac © 2013 Pearson Education, Inc. Alveolar pores Respiratory Membrane • Alveolar and capillary walls and their fused basement membranes – ~0.5-µm-thick; gas exchange across membrane by simple diffusion • Alveolar walls – Single layer of squamous epithelium (type I alveolar cells) • Scattered cuboidal type II alveolar cells secrete surfactant and antimicrobial proteins © 2013 Pearson Education, Inc. Figure 22.9a Alveoli and the respiratory membrane. Terminal bronchiole Respiratory bronchiole Smooth muscle Elastic fibers Alveolus Capillaries Diagrammatic view of capillary-alveoli relationships © 2013 Pearson Education, Inc. Figure 22.9b Alveoli and the respiratory membrane. Scanning electron micrograph of pulmonary capillary casts (70x) © 2013 Pearson Education, Inc. Alveoli • Surrounded by fine elastic fibers and pulmonary capillaries • Alveolar pores connect adjacent alveoli • Equalize air pressure throughout lung • Alveolar macrophages keep alveolar surfaces sterile – 2 million dead macrophages/hour carried by cilia throat swallowed © 2013 Pearson Education, Inc. Figure 22.9c Alveoli and the respiratory membrane. Red blood cell Nucleus of type I alveolar cell Alveolar pores Capillary Capillary Macrophage Endothelial cell nucleus Alveolus Respiratory membrane Alveoli (gas-filled air spaces) Red blood cell in capillary Type II alveolar cell Type I alveolar cell Detailed anatomy of the respiratory membrane © 2013 Pearson Education, Inc. Alveolus Alveolar epithelium Fused basement membranes of alveolar epithelium and capillary endothelium Capillary endothelium Figure 22.10c Anatomical relationships of organs in the thoracic cavity. Vertebra Right lung Parietal pleura Visceral pleura Pleural cavity Posterior Esophagus (in mediastinum) Root of lung at hilum • Left main bronchus • Left pulmonary artery • Left pulmonary vein Left lung Thoracic wall Pulmonary trunk Pericardial membranes Sternum Heart (in mediastinum) Anterior mediastinum Anterior Transverse section through the thorax, viewed from above. Lungs, pleural membranes, and major organs in the mediastinum are shown. © 2013 Pearson Education, Inc. Figure 22.10a Anatomical relationships of organs in the thoracic cavity. Intercostal muscle Rib Lung Parietal pleura Pleural cavity Visceral pleura Trachea Thymus Apex of lung Left superior lobe Right superior lobe Horizontal fissure Right middle lobe Oblique fissure Oblique fissure Left inferior lobe Right inferior lobe Heart (in mediastinum) Diaphragm Cardiac notch Base of lung Anterior view. The lungs flank mediastinal structures laterally. © 2013 Pearson Education, Inc. Figure 22.10b Anatomical relationships of organs in the thoracic cavity. Apex of lung Pulmonary artery Left superior lobe Oblique fissure Pulmonary vein Left inferior lobe Cardiac impression Hilum of lung Oblique fissure Aortic impression © 2013 Pearson Education, Inc. Left main bronchus Lobules Photograph of medial view of the left lung. Figure 22.11 A cast of the bronchial tree. Right lung Right superior lobe (3 segments) Left lung Left superior lobe (4 segments) Right middle lobe (2 segments) Right inferior lobe (5 segments) © 2013 Pearson Education, Inc. Left inferior lobe (5 segments) Blood Supply • Pulmonary circulation (low pressure, high volume) – Pulmonary arteries deliver systemic venous blood to lungs for oxygenation • Branch profusely; feed into pulmonary capillary networks – Pulmonary veins carry oxygenated blood from respiratory zones to heart © 2013 Pearson Education, Inc. Figure 22.10c Anatomical relationships of organs in the thoracic cavity. Vertebra Right lung Parietal pleura Visceral pleura Pleural cavity Posterior Esophagus (in mediastinum) Root of lung at hilum • Left main bronchus • Left pulmonary artery • Left pulmonary vein Left lung Thoracic wall Pulmonary trunk Pericardial membranes Sternum Heart (in mediastinum) Anterior mediastinum Anterior Transverse section through the thorax, viewed from above. Lungs, pleural membranes, and major organs in the mediastinum are shown. © 2013 Pearson Education, Inc. Mechanics of Breathing • Pulmonary ventilation consists of two phases – Inspiration-gases flow into lungs – Expiration-gases exit lungs © 2013 Pearson Education, Inc. Figure 22.12 Intrapulmonary and intrapleural pressure relationships. Atmospheric pressure (Patm) 0 mm Hg (760 mm Hg) Parietal pleura Thoracic wall Visceral pleura Pleural cavity Transpulmonary pressure 4 mm Hg (the difference between 0 mm Hg and −4 mm Hg) –4 0 Lung Diaphragm © 2013 Pearson Education, Inc. Intrapulmonary pressure (Ppul) 0 mm Hg (760 mm Hg) Intrapleural pressure (Pip) −4 mm Hg (756 mm Hg) Homeostatic Imbalance • Atelectasis (lung collapse) due to – Plugged bronchioles collapse of alveoli – Pneumothorax-air in pleural cavity • From either wound in parietal or rupture of visceral pleura • Treated by removing air with chest tubes; pleurae heal lung reinflates © 2013 Pearson Education, Inc. Figure 22.13 Changes in thoracic volume and sequence of events during inspiration and expiration. (1 of 2) Slide 1 Sequence of events Changes in anterior-posterior and superior-inferior dimensions Changes in lateral dimensions (superior view) 1 Inspiratory muscles contract (diaphragm descends; rib cage rises). Inspiration 2 Thoracic cavity volume increases. 3 Lungs are stretched; intrapulmonary volume increases. Ribs are elevated and sternum flares as external intercostals contract. External intercostals contract. 4 Intrapulmonary pressure drops (to –1 mm Hg). 5 Air (gases) flows into lungs down its pressure gradient until intrapulmonary pressure is 0 (equal to atmospheric pressure). © 2013 Pearson Education, Inc. Diaphragm moves inferiorly during contraction. Expiration • Quiet expiration normally passive process – Inspiratory muscles relax – Thoracic cavity volume decreases – Elastic lungs recoil and intrapulmonary volume decreases pressure increases (Ppul rises to +1 mm Hg) – Air flows out of lungs down its pressure gradient until Ppul = 0 • Note: forced expiration-active process; uses abdominal (oblique and transverse) and internal intercostal muscles © 2013 Pearson Education, Inc. Figure 22.13 Changes in thoracic volume and sequence of events during inspiration and expiration. (2 of 2) Slide 1 Sequence of events Changes in anterior-posterior and superior-inferior dimensions Changes in lateral dimensions (superior view) 1 Inspiratory muscles relax (diaphragm rises; rib cage descends due to recoil of costal cartilages). Expiration 2 Thoracic cavity volume decreases. 3 Elastic lungs recoil passively; intrapulmonary Volume decreases. Ribs and sternum are depressed as external intercostals relax. External intercostals relax. 4 Intrapulmonary pressure rises (to +1 mm Hg). 5 Air (gases) flows out of lungs down its pressure gradient until intrapulmonary pressure is 0. © 2013 Pearson Education, Inc. Diaphragm moves superiorly as it relaxes. Homeostatic Imbalance • As airway resistance rises, breathing movements become more strenuous • Severe constriction or obstruction of bronchioles – Can prevent life-sustaining ventilation – Can occur during acute asthma attacks; stops ventilation • Epinephrine dilates bronchioles, reduces air resistance © 2013 Pearson Education, Inc. Alveolar Surface Tension • Surfactant – Detergent-like lipid and protein complex produced by type II alveolar cells – Reduces surface tension of alveolar fluid and discourages alveolar collapse – Insufficient quantity in premature infants causes infant respiratory distress syndrome • alveoli collapse after each breath © 2013 Pearson Education, Inc.