Respiratory System PDF

PowerPoint® Lecture Slides prepared by Vince Austin, University of Kentucky The Respiratory System Part A 22 Human Anatomy & Physiology, Sixth Edition Elaine N. Marieb Copyright © 2004 Pearson Educati...

PowerPoint® Lecture Slides prepared by Vince Austin, University of Kentucky The Respiratory System Part A 22 Human Anatomy & Physiology, Sixth Edition Elaine N. Marieb Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Respiratory System ▪ Consists of the respiratory and conducting zones ▪ Respiratory zone ▪ Site of gas exchange ▪ Consists of bronchioles, alveolar ducts, and alveoli Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Respiratory System ▪ Conducting zone ▪ Includes all other respiratory structures (e.g., nose, nasal cavity, pharynx, trachea) ▪ Respiratory muscles – diaphragm and other muscles that promote ventilation Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Respiratory System Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 22.1  Major Functions of the Respiratory System ▪ To supply the body with oxygen and dispose of carbon dioxide ▪ Respiration – four distinct processes must happen ▪ Pulmonary ventilation – moving air into and out of the lungs ▪ External respiration – gas exchange between the lungs and the blood Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Major Functions of the Respiratory System ▪ Transport – transport of oxygen and carbon dioxide between the lungs and tissues ▪ Internal respiration – gas exchange between systemic blood vessels and tissues Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Function of the Nose ▪ The only externally visible part of the respiratory system that functions by: ▪ Providing an airway for respiration ▪ Moistening and warming the entering air ▪ Filtering inspired air and cleaning it of foreign matter ▪ Housing the olfactory receptors Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Nasal Cavity ▪ Respiratory mucosa ▪ Lines the balance of the nasal cavity ▪ Glands secrete mucus containing lysozyme to help destroy bacteria Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Nasal Cavity Figure 22.3b Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Pharynx ▪ Funnel-shaped tube of skeletal muscle that connects to the: ▪ Nasal cavity and mouth superiorly ▪ Larynx and esophagus inferiorly ▪ Extends from the base of the skull to the level of the sixth cervical vertebra Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Pharynx ▪ It is divided into three regions ▪ Nasopharynx ▪ Oropharynx ▪ Laryngopharynx Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Nasopharynx ▪ Lies posterior to the nasal cavity, inferior to the sphenoid, and superior to the level of the soft palate ▪ Strictly an air passageway ▪ Closes during swallowing to prevent food from entering the nasal cavity ▪ The pharyngeal tonsil lies high on the posterior wall ▪ Pharyngotympanic (auditory) tubes open into the lateral walls Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Oropharynx ▪ Extends inferiorly from the level of the soft palate to the epiglottis ▪ Serves as a common passageway for food and air ▪ The epithelial lining is protective stratified squamous epithelium ▪ Palatine tonsils ▪ Lingual tonsil Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Laryngopharynx ▪ Serves as a common passageway for food and air ▪ Lies posterior to the upright epiglottis ▪ Extends to the larynx, where the respiratory and digestive pathways diverge Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Larynx (Voice Box) ▪ Attaches to the hyoid bone and opens into the laryngopharynx superiorly ▪ Continuous with the trachea posteriorly Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Framework of the Larynx ▪ Cartilages (hyaline) of the larynx ▪ Shield-shaped anterosuperior thyroid cartilage with a midline laryngeal prominence (Adam’s apple) ▪ Signet ring–shaped anteroinferior cricoid cartilage ▪ Epiglottis – elastic cartilage that covers the laryngeal inlet during swallowing Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Framework of the Larynx Figure 22.4a, b Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Vocal Ligaments ▪ Composed of elastic fibers that form mucosal folds called true vocal cords ▪ The medial opening between them is the glottis ▪ They vibrate to produce sound as air rushes up from the lungs Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Vocal Ligaments ▪ False vocal cords ▪ Mucosal folds superior to the true vocal cords ▪ Have no part in sound production Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Trachea ▪ Mucosa – made up of goblet cells and ciliated epithelium ▪ Submucosa – connective tissue deep to the mucosa ▪ Adventitia – outermost layer made of C-shaped rings of hyaline cartilage Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Trachea Figure 22.6a Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Conducting Zone: Bronchi ▪ Air reaching the bronchi is: ▪ Warm and cleansed of impurities ▪ Saturated with water vapor ▪ Bronchi subdivide into secondary bronchi, each supplying a lobe of the lungs ▪ Air passages undergo 23 orders of branching in the lungs Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Conducting Zone: Bronchial Tree ▪ Tissue walls of bronchi mimic that of the trachea ▪ As conducting tubes become smaller, structural changes occur ▪ Cartilage support structures change ▪ Amount of smooth muscle increases Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Conducting Zone: Bronchial Tree ▪ Bronchioles ▪ Have a complete layer of circular smooth muscle ▪ Lack cartilage support and mucus-producing cells Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Respiratory Zone ▪ Defined by the presence of alveoli; begins as terminal bronchioles feed into respiratory bronchioles ▪ Respiratory bronchioles lead to alveolar ducts, then to terminal clusters of alveolar sacs composed of alveoli ▪ Approximately 300 million alveoli: ▪ Account for most of the lungs’ volume ▪ Provide tremendous surface area for gas exchange Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Respiratory Zone Figure 22.8a Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Respiratory Zone Figure 22.8b Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Respiratory Membrane Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 22.9b  Respiratory Membrane Figure 22.9.c, d Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Lungs ▪ Cardiac notch (impression) – cavity that accommodates the heart ▪ Left lung – separated into upper and lower lobes by the oblique fissure ▪ Right lung – separated into three lobes by the oblique and horizontal fissures Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Pleurae ▪ Thin, double-layered serosa ▪ Parietal pleura ▪ Covers the thoracic wall and superior face of the diaphragm ▪ Continues around heart and between lungs Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Pleurae ▪ Visceral, or pulmonary, pleura ▪ Covers the external lung surface ▪ Divides the thoracic cavity into three chambers ▪ The central mediastinum ▪ Two lateral compartments, each containing a lung Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Breathing ▪ Breathing, or pulmonary ventilation, consists of two phases ▪ Inspiration – air flows into the lungs ▪ Expiration – gases exit the lungs Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Pressure Relationships Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 22.12  Inspiration Figure 22.13.1 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings  Expiration Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 22.13.2