22 PART 1 The Respiratory System Pages 645

22 PART 1 The Respiratory System Pages 645 -665 Power. Point® Lecture Presentations prepared by Leslie Hendon University of Alabama, Birmingham © 2014 Pearson Education, Inc.

The Respiratory System • Basic functions of the respiratory system • Supplies body with oxygen • Disposes of carbon dioxide • Four processes involved in respiration • Pulmonary ventilation • External respiration • Transport of respiratory gases • Internal respiration © 2014 Pearson Education, Inc.

Functional Anatomy of the Respiratory System • Respiratory organs • Nose, nasal cavity, and paranasal sinuses • Pharynx, larynx, and trachea • Bronchi and smaller branches • Lungs and alveoli © 2014 Pearson Education, Inc.

Organs of the Respiratory System Nasal cavity Nostril Larynx Trachea Carina of trachea Right main (primary) bronchus Right lung Parietal pleura © 2014 Pearson Education, Inc. Oral cavity Pharynx Left main (primary) bronchus Bronchi Alveoli Left lung Diaphragm Figure 22. 1

Organs of the Respiratory System • Divided into • Conducting zone • Respiratory zone © 2014 Pearson Education, Inc.

The Nose • Provides an airway for respiration • Moistens and warms air • Filters inhaled air • Resonating chamber for speech • Houses olfactory receptors © 2014 Pearson Education, Inc.

The Nose • Size variation due to differences in nasal cartilages • Skin is thin—contains many sebaceous glands Frontal bone Epicranius, frontal belly Root and bridge of nose Dorsum nasi Ala of nose Apex of nose Naris (nostril) Philtrum (a) Surface anatomy © 2014 Pearson Education, Inc. Nasal bone Septal cartilage Maxillary bone (frontal process) Lateral process of septal cartilage Minor alar cartilages Dense fibrous connective tissue Major alar cartilages (b) External skeletal framework Figure 22. 2

The Nasal Cavity • External nares—nostrils • Divided by nasal septum • Continuous with nasopharynx • Posterior nasal apertures—choanae © 2014 Pearson Education, Inc.

Nasal Cavity • Two types of mucous membrane • Olfactory mucosa • Near roof of nasal cavity • Houses olfactory (smell) receptors • Respiratory mucosa • Lines nasal cavity • Epithelium is pseudostratified ciliated columnar © 2014 Pearson Education, Inc.

The Upper Respiratory Tract Cribriform plate of ethmoid bone Sphenoid sinus Posterior nasal aperture Nasopharynx Pharyngeal tonsil Opening of pharyngotympanic tube Uvula Oropharynx Palatine tonsil Isthmus of the fauces Laryngopharynx Esophagus Trachea (c) Illustration © 2014 Pearson Education, Inc. Frontal sinus Nasal cavity Nasal conchae (superior, middle and inferior) Nasal meatuses (superior, middle, and inferior) Nasal vestibule Nostril Hard palate Soft palate Tongue Larynx Lingual tonsil Hyoid bone Epiglottis Vestibular fold Thyroid cartilage Vocal fold Cricoid cartilage Thyroid gland Figure 22. 3

Nasal Conchae • Superior and middle nasal conchae • Part of the ethmoid bone • Inferior nasal conchae • Separate bone • Project medially from the lateral wall of the nasal cavity © 2014 Pearson Education, Inc.

The Pharynx • Funnel-shaped passageway • Connects nasal cavity and mouth • Divided into three sections by location • Nasopharynx • Oropharynx • Laryngopharynx • Type of mucosal lining changes along its length © 2014 Pearson Education, Inc.

© 2014 Pearson Education, Inc.

The Upper Respiratory Tract Cribriform plate of ethmoid bone Sphenoid sinus Posterior nasal aperture Nasopharynx Pharyngeal tonsil Opening of pharyngotympanic tube Uvula Oropharynx Palatine tonsil Isthmus of the fauces Laryngopharynx Esophagus Trachea (c) Illustration © 2014 Pearson Education, Inc. Frontal sinus Nasal cavity Nasal conchae (superior, middle and inferior) Nasal meatuses (superior, middle, and inferior) Nasal vestibule Nostril Hard palate Soft palate Tongue Larynx Lingual tonsil Hyoid bone Epiglottis Vestibular fold Thyroid cartilage Vocal fold Cricoid cartilage Thyroid gland Figure 22. 3

The Nasopharynx • Superior to the point where food enters • Only an air passageway • Closed off during swallowing • Pharyngeal tonsil (adenoids) • Located on posterior wall • Destroys entering pathogens • Contains the opening to the pharyngotympanic tube (auditory tube) © 2014 Pearson Education, Inc.

The Oropharynx • Arch-like entranceway—fauces • Extends from soft palate to the epiglottis • Epithelium • Stratified squamous epithelium • Two types of tonsils in the oropharynx • Palatine tonsils—in the lateral walls of the fauces • Lingual tonsils—covers the posterior surface of the tongue © 2014 Pearson Education, Inc.

The Upper Respiratory Tract Cribriform plate of ethmoid bone Sphenoid sinus Posterior nasal aperture Nasopharynx Pharyngeal tonsil Opening of pharyngotympanic tube Uvula Oropharynx Palatine tonsil Isthmus of the fauces Laryngopharynx Esophagus Trachea (c) Illustration © 2014 Pearson Education, Inc. Frontal sinus Nasal cavity Nasal conchae (superior, middle and inferior) Nasal meatuses (superior, middle, and inferior) Nasal vestibule Nostril Hard palate Soft palate Tongue Larynx Lingual tonsil Hyoid bone Epiglottis Vestibular fold Thyroid cartilage Vocal fold Cricoid cartilage Thyroid gland Figure 22. 3

The Laryngopharynx • Passageway for both food and air • Epithelium • Stratified squamous epithelium • Continuous with the esophagus and larynx © 2014 Pearson Education, Inc.

The Larynx • Three functions • Voice production • Provides an open airway • Routes air and food into the proper channels • Superior opening is • Closed during swallowing • Open during breathing © 2014 Pearson Education, Inc.

The Upper Respiratory Tract Cribriform plate of ethmoid bone Sphenoid sinus Posterior nasal aperture Nasopharynx Pharyngeal tonsil Opening of pharyngotympanic tube Uvula Oropharynx Palatine tonsil Isthmus of the fauces Laryngopharynx Esophagus Trachea (c) Illustration © 2014 Pearson Education, Inc. Frontal sinus Nasal cavity Nasal conchae (superior, middle and inferior) Nasal meatuses (superior, middle, and inferior) Nasal vestibule Nostril Hard palate Soft palate Tongue Larynx Lingual tonsil Hyoid bone Epiglottis Vestibular fold Thyroid cartilage Vocal fold Cricoid cartilage Thyroid gland Figure 22. 3

Nine Cartilages of the Larynx • Thyroid cartilage • Shield-shaped, forms laryngeal prominence (Adam’s apple) • Three pairs of small cartilages • Arytenoid cartilages • Corniculate cartilages • Cuneiform cartilages • Epiglottis • Tips inferiorly during swallowing © 2014 Pearson Education, Inc.

Anatomy of the Larynx Body of hyoid bone Laryngeal prominence (Adam’s apple) Cricoid cartilage Sternal head Clavicular head Sternocleidomastoid Clavicle Jugular notch (a) Surface view Epiglottis Thyrohyoid membrane Body of hyoid bone Thyroid cartilage Laryngeal prominence (Adam’s apple) Cricothyroid ligament Cricoid cartilage Cricotracheal ligament Tracheal cartilages © 2014 Pearson Education, Inc. (b) Anterior view Figure 22. 5 a, b

Anatomy of the Larynx Epiglottis Thyrohyoid membrane Hyoid bone Corniculate cartilage Arytenoid cartilage Thyroid cartilage Cricoid cartilage Glottis Tracheal cartilages (c) Photograph of cartilaginous framework of the larynx, posterior view Epiglottis Thyrohyoid membrane Cuneiform cartilage Corniculate cartilage Arytenoid muscle Cricoid cartilage Body of hyoid bone Thyrohyoid membrane Fatty pad Vestibular fold (false vocal cord) Thyroid cartilage Vocal fold (true vocal cord) Cricothyroid ligament Cricotracheal ligament Tracheal cartilages © 2014 Pearson Education, Inc. (d) Sagittal section (anterior on the right) Figure 22. 5 c, d

The Larynx • Vocal ligaments of the larynx • Vocal folds (true vocal cords) • Act in sound production • Vestibular folds (false vocal cords) • No role in sound production • Epithelium of the larynx • Stratified squamous—superior portion • Pseudostratified ciliated columnar—inferior portion © 2014 Pearson Education, Inc.

Movements of the Vocal Folds Anterior Thyroid cartilage Cricoid cartilage Vocal ligaments of vocal cords Glottis Lateral cricoarytenoid muscle Arytenoid cartilage Corniculate cartilage Posterior cricoarytenoid muscle Posterior Base of tongue Epiglottis Vestibular fold (false vocal cord) Vocal fold (true vocal cord) Glottis Inner lining of trachea Cuneiform cartilage Corniculate cartilage (a) Vocal folds in closed position; closed glottis © 2014 Pearson Education, Inc. (b) Vocal folds in open position; open glottis Figure 22. 6

The Trachea • Descends into the mediastinum • C-shaped cartilage rings keep airway open • Carina • Marks where trachea divides into two primary bronchi • Epithelium • Pseudostratified ciliated columnar © 2014 Pearson Education, Inc.

Organs of the Respiratory System Nasal cavity Nostril Larynx Trachea Carina of trachea Right main (primary) bronchus Right lung Parietal pleura © 2014 Pearson Education, Inc. Oral cavity Pharynx Left main (primary) bronchus Bronchi Alveoli Left lung Diaphragm Figure 22. 1

The Trachea Mucosa Pseudostratified ciliated columnar epithelium Lamina propria (connective tissue) Submucosa Seromucous gland in submucosa Posterior Hyaline cartilage Mucosa Esophagus Submucosa Trachealis muscle Lumen of trachea (b) Photomicrograph of the tracheal wall (250 ) Seromucous gland in submucosa Hyaline cartilage Adventitia Anterior (a) Cross section of the trachea and esophagus © 2014 Pearson Education, Inc. Figure 22. 7

Bronchi in the Conducting Zone • Bronchial tree • Extensively branching respiratory passageways • Primary bronchi (main bronchi) • Largest bronchi • Right main bronchi • Wider and shorter than the left © 2014 Pearson Education, Inc.

Bronchi in the Conducting Zone Superior lobe of right lung Trachea Superior lobe of left lung Left main (primary) bronchus Lobar (secondary) bronchus Segmental (tertiary) bronchus Inferior lobe of left lung Middle lobe Inferior lobe of right lung (a) The branching of the bronchial tree © 2014 Pearson Education, Inc. Figure 22. 8 a

Bronchi in the Conducting Zone • Secondary (lobar) bronchi • Three on the right • Two on the left • Tertiary (segmental) bronchi • Branch into each lung segment • Bronchioles • Little bronchi, less than 1 mm in diameter • Terminal bronchioles • Less than 0. 5 mm in diameter © 2014 Pearson Education, Inc.

Figure 22. 12 Bronchopulmonary segments. Apicoposterior Apical Superior Posterior Anterior Superior Lateral Medial Inferior Middle Inferior Superior Lingular Superior Anterior basal Medial basal Lateral basal Posterior basal Medial basal Inferior Lateral basal Posterior basal Segmental bronchi Superior lobe Apical Posterior Anterior Superior lingular Middle lobe Inferior lingular Lateral Medial Lingular division Inferior lobe Superior Inferior lobe Anterior basal Superior Lateral basal Anterior basal Lateral basal Right lung Left lung Distribution of bronchiopulmonary segments on lateral surface of lungs © 2014 Pearson Education, Inc. Superior division

Changes in Tissue Composition along Conducting Pathways • Supportive connective tissues change • C-shaped rings replaced by cartilage plates • Epithelium changes • First, pseudostratified ciliated columnar • Replaced by simple columnar, then simple cuboidal epithelium • Smooth muscle becomes important • Airways widen with sympathetic stimulation • Airways constrict under parasympathetic direction © 2014 Pearson Education, Inc.

Figure 22. 8 b The bronchi in the conducting zone. Mucosa Pseudostratified epithelium Lamina propria Lumen Fibromusculocartilaginous layer Cartilage plate Smooth muscle Photomicrograph of a bronchus (35 ) © 2014 Pearson Education, Inc.

Structures of the Respiratory Zone • Consists of air-exchanging structures • Respiratory bronchioles—branch from terminal bronchioles • Lead to alveolar ducts • Lead to alveolar sacs © 2014 Pearson Education, Inc.

Structures of the Respiratory Zone Alveoli Alveolar duct Respiratory bronchioles Terminal bronchiole Alveolar duct Alveolar sac (a) © 2014 Pearson Education, Inc. Figure 22. 9 a

Figure 22. 9 b Structures of the respiratory zone. Respiratory bronchiole Alveolar duct Alveoli Alveolar sac © 2014 Pearson Education, Inc. Alveolar pores

Structures of the Respiratory Zone • Alveoli • ~300 million alveoli account for tremendous surface area of the lungs • Structure of alveoli • Type I cells—single layer of simple squamous epithelial cells • Surrounded by basal lamina • Alveolar and capillary walls plus their basal lamina form • Respiratory membrane © 2014 Pearson Education, Inc.

Anatomy of Alveoli and the Respiratory Membrane Terminal bronchiole Respiratory bronchiole Smooth muscle Elastic fibers Alveolus Capillaries (a) Diagrammatic view of capillary-alveoli relationships © 2014 Pearson Education, Inc. Figure 22. 10 a, b

Anatomy of Alveoli and the Respiratory Membrane Red blood cell Nucleus of type I (squamous epithelial) cell Alveolar pores Capillary O 2 Macrophage Endothelial cell nucleus Alveolus Respiratory membrane Red blood cell Type I cell in capillary of alveolar wall Alveoli (gas-filled Type II (surfactantair spaces) secreting) cell Capillary CO 2 Alveolus Alveolar epithelium Fused basement membranes of the alveolar epithelium and the capillary endothelium Capillary endothelium (c) Detailed anatomy of the respiratory membrane © 2014 Pearson Education, Inc. Figure 22. 10 c

Structures of the Respiratory Zone • Structures of alveoli (continued) • Type II cells—scattered among type I cells • Are cuboidal epithelial cells • Secrete surfactant • Reduces surface tension within alveoli • Alveolar macrophages © 2014 Pearson Education, Inc.

Gross Anatomy of the Lungs • Major landmarks of the lungs • Apex, base, hilum, and root • Left lung • Superior and inferior lobes • Fissure—oblique • Right lung • Superior, middle, and inferior lobes • Fissures—oblique and horizontal © 2014 Pearson Education, Inc.

Gross Anatomy of the Lungs Anterior View of Thoracic Structures Intercostal muscle Rib Parietal pleura Pleural cavity Visceral pleura Lung Pulmonary artery Trachea Thymus Apex of lung Left superior lobe Oblique fissure Left inferior lobe Right superior lobe Horizontal fissure Right middle lobe Oblique fissure Right inferior lobe Heart (in mediastinum) Diaphragm Left superior lobe Left main bronchus Oblique fissure Pulmonary vein Impression of heart Oblique fissure Left inferior lobe Hilum Cardiac notch Base of lung (a) Anterior view. The lungs flank mediastinal structures laterally. © 2014 Pearson Education, Inc. Apex of lung Aortic impression Lobules (b) Photograph of medial view of the left lung Figure 22. 11 a, b

Intercostal muscle Rib Parietal pleura Pleural cavity Visceral pleura Lung Trachea Thymus Apex of lung Right superior lobe Horizontal fissure Right middle lobe Oblique fissure Left superior lobe Oblique fissure Left inferior lobe Right inferior lobe Heart (in mediastinum) Diaphragm Cardiac notch Base of lung (a) Anterior view. The lungs flank mediastinal structures laterally. © 2014 Pearson Education, Inc. Figure 22. 11 a

Blood Supply and Innervation of the Lungs • Pulmonary arteries • Deliver oxygen-poor blood to the lungs • Pulmonary veins • Carry oxygenated blood to the heart © 2014 Pearson Education, Inc.

Transverse Cut through the Superior Thorax 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 (d) Transverse section through the thorax, viewed from above. Lungs, pleural membranes, and major organs in the mediastinum are shown. © 2014 Pearson Education, Inc. Figure 22. 11 d

The Pleurae • A double-layered sac surrounding each lung • Parietal pleura • Visceral pleura • Pleural cavity • Space between the visceral and parietal pleurae • Pleurae help divide thoracic cavity • Central mediastinum • Two lateral pleural compartments © 2014 Pearson Education, Inc.

Diagram of the Pleurae and Pleural Cavities Intercostal muscle Rib Parietal pleura Pleural cavity Visceral pleura Lung Trachea Thymus Apex of lung Right superior lobe Horizontal fissure Right middle lobe Oblique fissure Left superior lobe Oblique fissure Left inferior lobe Right inferior lobe Heart (in mediastinum) Diaphragm Cardiac notch Base of lung (a) Anterior view. The lungs flank mediastinal structures laterally. © 2014 Pearson Education, Inc. Figure 22. 11 a

The Mechanisms of Ventilation • Two phases of pulmonary ventilation • Inspiration—inhalation • Expiration—exhalation © 2014 Pearson Education, Inc.

Inspiration • Volume of thoracic cavity increases • Decreases internal gas pressure • Action of the diaphragm • Diaphragm flattens • Action of intercostal muscles • Contraction raises the ribs © 2014 Pearson Education, Inc.

Expiration • Quiet expiration—chiefly a passive process • Inspiratory muscles relax • Diaphragm moves superiorly • Volume of thoracic cavity decreases © 2014 Pearson Education, Inc.

Figure 22. 14 Changes in thoracic volume and sequence of events during inspiration and expiration. 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 and pleural cavity increase in volume. Ribs are elevated and sternum flares as external intercostals contract. 3 Lungs are stretched; lung volume increases. External intercostals contract. 4 Air pressure in lungs decreases. 5 Air (gases) flows into lungs. Diaphragm moves inferiorly during contraction. 1 Inspiratory muscles relax (diaphragm rises; rib cage descends because of recoil of costal cartilages). Exspiration 2 Thoracic cavity and pleural cavity decrease in volume. Ribs and sternum are depressed as external intercostals relax. 3 Elastic lungs recoil passively; lung volume decreases. External intercostals relax. 4 Air pressure in lungs rises. 5 Air (gases) flows out of lungs. © 2014 Pearson Education, Inc. Diaphragm moves superiorly as it relaxes.