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Download Chapter 25-Respiratory System
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Chapter 25 Respiratory System Fig. 25.1 • Upper respiratory tract • Sinuses • Nasal cavity • Pharynx • Lower respiratory tract • • • • Larynx Trachea Bronchi Lungs Sphenoidal sinus Frontal sinus Nasal cavity Upper respiratory Pharynx tract Larynx Trachea Lower respiratory Bronchi tract Lungs Pleura Diaphragm Fig. 25.1 • Conducting portion transports air • Nose, nasal cavity, pharynx, larynx, trachea, airways • Respiratory portion does gas exchange • respiratory bronchioles, alveolar ducts, alveoli (air sacs) Sphenoidal sinus Frontal sinus Nasal cavity Upper respiratory Pharynx tract Larynx Trachea Lower respiratory Bronchi tract Lungs Pleura Diaphragm External Respiration • Exchange of gases between atmosphere and blood • inhalation of air • diffusion into blood Internal Respiration • Exchange of gases between blood and cells of the body • transport from lungs to body and back Other Functions • Gas conditioning • warming • humidifying • cleansing of particulates • Sound production • Olfaction • Defense Fig. 25.10 • Lungs surrounded by pleura Parietal pleura Visceral pleura Pleural cavity • simple squamous epithelium called mesothelium Parietal pleura Pleural cavity Visceral pleura Diaphragm • Outer surface is parietal pleura • Inner surface (contact with lung) is visceral pleura • Pleural cavity divides pleural layers, has thin layer of fluid Fig. 25.11 Apex Superior lobe Horizontal fissure Oblique fissure Middle lobe Cardiac notch Inferior lobe Lingula Base Right lung Left lung (a) Lateral views Fig. 25.11 Apex Superior lobe Oblique fissure Pulmonary artery Main bronchus Pulmonary veins Hilum Root of the lung Horizontal fissure Cardiac impression Cardiac notch Middle lobe Inferior lobe Oblique fissure Oblique fissure Base Right lung Lingula Left lung (b) Medial views Fig. 25.2 Superior nasal concha Middle nasal concha Nasal Inferior nasal concha cavity Vestibule Nostril Hard palate • Vestibule is area behind nostrils Superior meatus Middle meatus Inferior meatus Nasal cavity • Nasal cavity includes nasal conchae (bony ridges) • Divide nasal cavity into 3 air passages called nasal meatus • Create turbulence, slow air passage, ensure air is warmed and humidified Fig. 25.2 Superior nasal concha Middle nasal concha Nasal Inferior nasal concha cavity Vestibule Nostril Hard palate • Hard palate is bottom of nasal cavity • Nasal septum divides right and left sides Superior meatus Middle meatus Inferior meatus Nasal cavity • Nasal cavity is lined with pseudostratified ciliated columnar epithelium with goblet cells • produce mucus • highly vascularized Fig. 25.2 Paranasal sinuses Frontal sinus Sphenoidal sinus • Paranasal sinuses named for bone • frontal sinus housed in frontal bone • sphenoidal sinus housed in sphenoid bone • maxillary sinuses housed in maxillary bone Fig. 25.3 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Frontal Ethmoidal Sphenoidal Maxillary Fig. 25.2 • Pharynx = throat • divided into 3 parts • pathway for food and air until epiglottis • Nasopharynx usually for air only Pharynx: Nasopharynx Oropharynx Laryngopharynx (b) Regions of pharynx • soft palate blocks food from mouth • lined with pseudostratified ciliated columnar epithelium • Oropharynx pathway for air and food • lined with non-keratinized stratified squamous epithelium • Laryngopharynx extends from hyoid bone to larynx and esophagus • lined with non-keratinized stratified squamous epithelium • Auditory tube opens into nasopharynx • Soft palate lifts to block passage of food to nasal cavity during swallowing Fig. 25.2 Opening of auditory tube Soft palate Uvula Nasopharynx Oropharynx Laryngopharynx Palatine tonsil Lingual tonsil Pharynx Fig. 25.2 • Tonsils provide first line of defense in immune system Pharyngeal tonsil Nasopharynx Oropharynx Laryngopharynx Palatine tonsil Lingual tonsil Pharynx • Epiglottis flips down during swallowing to cover opening to trachea • Food passes down esophagus Fig. 25.2 Nasopharynx Oropharynx Laryngopharynx Larynx Epiglottis Thyroid cartilage Cricoid cartilage Esophagus Trachea Pharynx Fig. 25.2 • Larynx is voice box • Air passage • Produces sound Epiglottis Larynx Thyroid cartilage Cricoid cartilage Fig. 25.4 Epiglottis Hyoid bone Thyrohyoid membrane (extrinsic) Thyroid cartilage Thyrohyoid muscle (extrinsic) Laryngeal prominence Cricothyroid muscle (extrinsic) Cricoid cartilage Cricotracheal ligament (extrinsic) Trachea (a) Anterior view • Opening to larynx is laryngeal inlet • 9 pieces of cartilage • held in place by ligaments and muscles • Thyroid cartilage is largest • front has v-shaped projection called laryngeal prominence • creates Adam’s apple Fig. 25.6 • Trachea = windpipe • Kept open by tracheal cartilage rings Esophagus Thyroid cartilage Larynx Cricoid cartilage Trachea Tracheal cartilage Anular ligament Right main Left main bronchus bronchus • C-shaped • connected by ligaments • open ends connected by trachealis muscle and elastic, ligamentous membrane • pushes against trachea during swallowing • contracts during coughing; decreases diameter of trachea, increases speed of airflow Tracheotomy Trachea Thyroid cartilage Thyroid gland Suprasternal notch Tracheotomy tube Cricoid cartilage Incision 1 Incision is made superior to suprasternal notch. Thyroid may have to be cut as well. Scalpel Sutures 2 Retractors separate the tissue, and an incision is made through the third and fourth tracheal rings. 3 A tracheotomy tube is inserted, and the remaining incision is sutured closed. Fig. 25.6 Posterior Esophagus • Trachea cross-section • Lined with pseudostratified ciliated columnar epithelium • goblet cells secrete mucin • cilia propels mucus and dust toward larynx and pharynx for swallowing Trachealis muscle Lumen of trachea Mucosa Submucosa Tracheal cartilage LM 8x Anterior Fig. 25.6 Mucosa Trachea cross-section Pseudostratified Lamina ciliated columnar propria epithelium Basement Submucosa membrane Posterior Esophagus Trachealis muscle Lumen of trachea Mucosa Submucosa Mucus Lumen Tracheal cartilage LM 8x Anterior (d) • Lined with pseudostratified ciliated columnar epithelium • goblet cells secrete mucin • cilia propels mucus and dust toward larynx and pharynx for swallowing Fig. 25.6 • Trachea splits at sternal angle into left and right main bronchi Trachea Carina (internal projection) Right main bronchus Left main bronchus Fig. 25.7 Main bronchi Lobar bronchi Larynx Segmental bronchi Smaller bronchi Trachea (b) Right main bronchus Left main bronchus Right lobar bronchus Right segmental bronchus Left lobar bronchus Left segmental bronchus Smaller bronchi Smaller bronchi Fig. 25.8 • Bronchi branch into bronchioles • lined with simple columnar or cuboidal epithelium • no cartilage in walls • smooth muscle around walls causes bronchoconstriction/ bronchodilation • Terminal bronchioles are end of conducting pathway Bronchiole Branch of pulmonary artery Terminal bronchiole Respiratory bronchiole Page 769 • Asthma causes bronchial constriction • Treatment is inhaled steroids Mucus Mucosa Submucosa Normal airway Swollen submucosa Mucosa Narrowed airway Extra mucous secretion Airway during an asthma attack • Terminal bronchioles branch into respiratory bronchioles Bronchiole • branch into smaller bronchioles • divide into alveolar ducts • lined with simple squamous epithelium • each ends in alveolar sac Branch of pulmonary vein Fig. 25.8 Branch of pulmonary artery Terminal bronchiole Pulmonary arteriole Pulmonary capillary beds Pulmonary venule Respiratory bronchiole Alveolar duct Alveoli Alveolar pores Interalveolar septum Alveolar sac Elastic fibers Connective tissue • Each alveolus is ¼ to ½ mm diameter • Thin wall promotes gas diffusion • Alveolar pores are holes between adjacent alveoli Bronchiole Branch of pulmonary artery Terminal bronchiole • promote gas diffusion Branch of pulmonary vein Fig. 25.8 Pulmonary arteriole Pulmonary capillary beds Pulmonary venule Respiratory bronchiole Alveolar duct Alveoli Alveolar pores Interalveolar septum Alveolar sac Elastic fibers Connective tissue Respiratory Alveolar bronchiole sac Alveolar ducts Terminal Respiratory bronchiole Alveoli bronchiole Alveoli Alveolar duct Fig. 25.8 LM 60x (b) SEM 180x (c) Fig. 25.9 • Pulmonary capillaries run between alveoli • Type I cells promote gas diffusion • Type II cells secrete surfactant Erythrocyte Pulmonary capillaries • reduces surface tension in fluid lining alveolua Alveolar type I cell Alveolar type II cell Alveolar macrophages Alveolar pores Interalveolar septum (a) • Macrophages consume foreign objects Fig. 25.9 Nucleus Nucleus of capillary endothelial cell Interalveolar of alveolar type I cell Erythrocyte septum Diffusion of CO2 Alveolus Respiratory membrane Diffusion of O2 Alveolar epithelium Fused basement membranes of the alveolar epithelium and the capillary endothelium Capillary endothelium Capillary Page 764 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Left lung Chest x-ray of a patient with pneumonia in the left lung. A normal lung appears as a black space on an x-ray because its spongy structure is not dense. In contrast, a pneumonia lung appears white or opaque on an x-ray due to accumulation of fluid and cells. © Collection CNRI/Phototake Page 764 Respiratory bronchiole Alveolar duct Alveoli Thickened alveolar walls Fluid and leukocytes in alveoli LM 30x Normal lung tissues. LM 75x Tissues within a lung affected by pneumonia. Page 770 Alveoli Enlarged alveolus Deposits Alveoli are small, numerous, and well formed. Nonsmoker’s lungs: Lungs are pink. Alveoli are enlarged, less numerous, and contain black deposits. Smoker’s lungs: Lungs are blackened.
