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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. 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. Functional Anatomy • Respiratory zone-site of gas exchange – Microscopic structures-respiratory bronchioles, alveolar ducts, and alveoli • Conducting zone-transit area to gas exchange sites: throat, trachea etc – Includes all other respiratory structures; cleanses, warms, humidifies air • Diaphragm and other respiratory muscles promote ventilation PLAY Animation: Rotating face © 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. The Nose • Two regions-external nose and nasal cavity • External nose-root, bridge, dorsum nasi, and apex – Philtrum-shallow vertical groove inferior to apex – Nostrils (nares)-bounded laterally by alae © 2013 Pearson Education, Inc. Figure 22.2a The external nose. Epicranius, frontal belly Root and bridge of nose Dorsum nasi Ala of nose Apex of nose Naris (nostril) Surface anatomy © 2013 Pearson Education, Inc. Figure 22.2b The external nose. Frontal bone Nasal bone Septal cartilage Maxillary bone (frontal process) Lateral process of septal cartilage Minor alar cartilages Dense fibrous connective tissue Major alar cartilages External skeletal framework © 2013 Pearson Education, Inc. The Nose • Nasal cavity-within and posterior to external nose – Divided by midline nasal septum – Posterior nasal apertures (choanae) open into nasal pharynx – Roof-ethmoid and sphenoid bones – Floor–hard (bone) and soft palates (muscle) © 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 • Olfactory mucosa contains olfactory epithelium • Respiratory mucosa – Pseudostratified ciliated columnar epithelium – Mucous and serous secretions contain lysozyme and defensins – Cilia move contaminated mucus posteriorly to throat – Inspired air warmed by plexuses of capillaries and veins – Sensory nerve endings trigger sneezing © 2013 Pearson Education, Inc. Figure 22.3b The upper respiratory tract. Cribriform plate of ethmoid bone Sphenoid 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. Nasal Cavity • Nasal conchae-superior, middle, and inferior – During inhalation, conchae and nasal mucosa • Filter, heat, and moisten air – During exhalation these structures • Reclaim heat and moisture © 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 from base of skull to C6 – 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 • 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 © 2013 Pearson Education, Inc. Laryngopharynx • Passageway for food and air • Posterior to upright epiglottis © 2013 Pearson Education, Inc. Figure 22.3b The upper respiratory tract. Cribriform plate of ethmoid bone Sphenoid 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. Larynx • Nine cartilages of larynx – All hyaline cartilage except epiglottis – Thyroid cartilage with laryngeal prominence (Adam's apple) – Epiglottis-elastic cartilage; covers laryngeal inlet during swallowing; covered in taste budcontaining mucosa © 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. Larynx • Vocal ligaments-deep to laryngeal mucosa – Contain elastic fibers – Folds vibrate to produce sound as air rushes up from lungs © 2013 Pearson Education, Inc. Larynx • Vestibular folds (false vocal cords) – Superior to vocal folds – No part in sound production – Help to close glottis during swallowing © 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 Voice Production • Speech-intermittent release of expired air while opening and closing glottis • Pitch determined by length and tension of vocal cords • Loudness depends upon force of air • Chambers of pharynx, oral, nasal, and sinus cavities amplify and enhance sound quality • Sound is "shaped" into language by muscles of pharynx, tongue, soft palate, and lips © 2013 Pearson Education, Inc. Larynx • Vocal folds may act as sphincter to prevent air passage • Example-Valsalva's maneuver – Glottis closes to prevent exhalation – Abdominal muscles contract – Intra-abdominal pressure rises – Helps to empty rectum or stabilizes trunk during heavy lifting © 2013 Pearson Education, Inc. Trachea • Windpipe–from larynx into mediastinum © 2013 Pearson Education, Inc. Trachea • Trachealis muscle – Connects posterior parts of cartilage rings – Contracts during coughing to expel mucus © 2013 Pearson Education, Inc. Figure 22.6a Tissue composition of the tracheal wall. Posterior Mucosa Esophagus Trachealis muscle Submucosa Lumen of trachea Seromucous gland in submucosa Hyaline cartilage Adventitia Anterior Cross section of the trachea and esophagus © 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. Bronchi • Tubes coming off each side of the bottom of the trachea © 2013 Pearson Education, Inc. Conducting Zone Structures • Trachea right and left main (primary) bronchi • Each main bronchus enters hilum of one lung – Right main bronchus wider, shorter, more vertical than left • Each main bronchus branches into lobar (secondary) bronchi (three on right, two on left) – Each lobar bronchus supplies one lobe © 2013 Pearson Education, Inc. Conducting Zone Structures • Each lobar bronchus branches into segmental (tertiary) bronchi – Segmental bronchi divide repeatedly • 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- m-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 Lungs • Occupy all thoracic cavity except mediastinum • Composed primarily of alveoli © 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. Lungs • Apex-superior tip; deep to clavicle • Base-inferior surface; rests on diaphragm • Hilum-on mediastinal surface; site for entry/exit of blood vessels, bronchi, lymphatic vessels, and nerves • Left lung smaller than right – Cardiac notch-concavity for heart – Separated into superior and inferior lobes by oblique fissure © 2013 Pearson Education, Inc. Lungs • Right lung – Superior, middle, inferior lobes separated by oblique and horizontal fissures • Bronchopulmonary segments (10 right, 8–10 left) separated by connective tissue septa – If diseased can be individually removed • Lobules-smallest subdivisions visible to naked eye; served by bronchioles and their branches © 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. Blood Supply – Lung capillary endothelium contains enzymes that act on substances in blood • E.g., angiotensin-converting enzyme–activates blood pressure hormone © 2013 Pearson Education, Inc. Blood Supply • Bronchial arteries provide oxygenated blood to lung tissue – Arise from aorta and enter lungs at hilum – Part of systemic circulation (high pressure, low volume) – Supply all lung tissue except alveoli – Bronchial veins anastomose with pulmonary veins • Pulmonary veins carry most venous blood back to heart © 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. 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. Pulmonary Ventilation • Inspiration and expiration • Mechanical processes that depend on volume changes in thoracic cavity – Volume changes pressure changes – Pressure changes gases flow to equalize pressure © 2013 Pearson Education, Inc. Inspiration • Active process – Inspiratory muscles (diaphragm and external intercostals) contract – Thoracic volume increases intrapulmonary pressure drops (to 1 mm Hg) – Lungs stretched and intrapulmonary volume increases – Air flows into lungs, down its pressure gradient, until Ppul = Patm © 2013 Pearson Education, Inc. 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.