The Respiratory System Chapter 23

Introduction Responsible for the exchange of gases between the body and the external environment. Cells need a supply of O2 and to eliminate CO2 3 basic processes Breathing External respiration Internal respiration Two systems supply O2 & eliminate CO2 Respiratory system Cardiovascular system

Human Anatomy, 3rd edition The Respiratory Tract Passageways through which air will move Terminate in the alveoli Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition The Respiratory Tract Upper respiratory system Superior to the larynx Functions – intake, moistening, filtering, sensing Lower respiratory system Larynx and below Functions – sound production, transport of air, gas exchange Human Anatomy, 3rd edition Prentice Hall, © 2001

The Respiratory Epithelium Lines the upper respiratory system Pseudostratified ciliated columnar epithelium with goblet cells Entraps & removes dust Moistens incoming air Olfactory sensation Capillaries warm incoming air The common cold Human Anatomy, 3rd edition Prentice Hall, © 2001

Surface View of the Epithelium FG24_02C.JPG Title: The Respiratory Epithelium Notes: (a)Diagrammatic view of the respiratory epithelium. (b)Sketch and light micrograph showing sectional appearance of respiratory epithelium. (c)Surface view of the epithelium. Keywords: respiratory epithelium, cilia, goblet cell, columnar, stern cell, basement membrane, lamina propria Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition The Nose Primary entrance to the respiratory system Bone & cartilage External nares Vestibule Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition The Nasal Cavity Nasal septum Divides into left and right sides Hard & soft palate form the floor Nasal conchae cause turbulence through meatuses Internal nares lead to the nasopharynx Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Paranasal Sinuses Frontal, sphenoid, ethmoidal, and maxillary sinuses Functions Lighten skull bones Produce mucus Resonate during sound production Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition The Pharynx Area from the internal nares to the larynx Shared between the respiratory and digestive systems Divided into 3 regions Nasopharynx Oropharynx Laryngopharynx Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition The Larynx Connects the laryngopharynx to the trachea Lined by mucus-producing columnar epithelium Functions Produces sound Vocal folds Keeps food from entering the airways Vestibular folds Epiglottis Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition The Larynx Formed by 9 cartilages Thyroid cartilage Cricoid cartilage Epiglottis Arytenoid cartilages Corniculate cartilages Cuneiform cartilages Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition The Larynx FG24_04A.JPG Title: Anatomy of the Larynx Notes: (a) Anterior view of the intact larynx. (b)Posterior view. (c)Sagittal section. (d)Posterior view; individual laryngeal cartilages. Keywords: larynx, anatomy, cornu, hyoid, extrinsic ligament, laryngeal prominence, intrinsic ligament, tracheal cartilage, trachea, larynx, epiglottis, thyroid cartliage, cricoid cartilage, vocal fold, ventricular fold, cartilage, thyrohyoid membrane Human Anatomy, 3rd edition Prentice Hall, © 2001

Movements of the Larynx During Swallowing Tongue forces bolus into the oropharynx Larynx is elevated Extrinsic laryngeal muscles Epiglottis closes over glottis Pharyngeal muscles push bolus into esophagus Larynx returns to normal position

Human Anatomy, 3rd edition Swallowing FG24_06A.JPG Title: Movements of the Larynx during Swallowing Notes: During swallowing the elevation of the larynx folds the epiglottis over the glottis, steering materials into the esophagus. Keywords: larynx, swallowing, epiglottis, glottis, esophagus, hard palate, bolus, larynx, soft palate Human Anatomy, 3rd edition Prentice Hall, © 2001

Voice Production Laryngeal ligaments lie under mucous membrane Intrinsic muscles attached to the cartilages Control vocal ligament tension Sound production Air flowing over vocal folds (through the glottis) produces sound waves Resonating chambers http://www.entdocsonline.com/images/larynx.jpg

Human Anatomy, 3rd edition The Trachea Extends from larynx to primary bronchi The “windpipe” Structure Incomplete cartilaginous rings Lined by mucus-producing epithelium Function – passageway for air Human Anatomy, 3rd edition Prentice Hall, © 2001

Bronchi, Bronchioles, & Alveoli Trachea divides into Primary bronchii divide into Secondary bronchi divide into Tertiary bronchi divide into Bronchioles divide into Terminal bronchioles divide into Respiratory bronchioles divide into Alveolar ducts end in Alveoli Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition The Respiratory Tree FG24_10D.JPG Title: The Bronchial Tree and Divisions of the Lungs, Anterior View Notes: (a)Gross anatomy of the lungs; bronchial tree and divisions. (b)Distribution of bronchopulmonary segments. (c)Bronchogram, slightly oblique, posteroanterior view. (d)Plastic cast of adult bronchial tree. Keywords: bronchopulmonary segments, distribution, bronchial tree, bronchus, apex of lung, diaphragm Human Anatomy, 3rd edition Prentice Hall, © 2001

Changes as the Respiratory Tree Branches As branching of bronchi becomes more extensive Rings of cartilage become plates Smooth muscle increases Columnar epithelium becomes cuboidal, then squamous (in alveoli) Asthma Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition The Alveoli Site of gas exchange with the blood Closely associated with capillaries Wall of the alveolus + wall of capillary Respiratory membrane Gas exchange occurs by diffusion Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Alveoli FG24_12B.JPG Title: Alveolar Organization Notes: (a) Basic structure of a lobule, cut to reveal the arrangement between the alveolar ducts and alveoli. (b)Connective tissue layers and alveolar vascular supply. (c)SEM of lung tissue. (d)Diagrammatic view of alveolar structure and respiratory membrane. Keywords: alveolar organization, alveolar sac, alveolar duct, respiratory bronchioles, alveoli, capillaries, surfactant cells, elastic fibers, alveolar macrophage, endothelial cell, respiratory membrane, basement membrane, surfactant Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition The Alveoli Alveolar epithelium contains: Alveolar Type 1 cells Gas exchange Emphysema Alveolar Type 2 cells Secrete surfactant Respiratory Distress Syndrome Macrophages Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition The Lungs Soft, spongy, cone-shaped Top = apex Bottom = base Right lung – 3 lobes Left lung – 2 lobes Hilus Blood supply Pulmonary arteries Pulmonary veins Human Anatomy, 3rd edition Prentice Hall, © 2001

Blood Supply to the Lungs FG24_08B.JPG Title: Superficial Anatomy of the Lungs Notes: (a) Anterior view of open chest, showing relative positions of lungs and heart. (b)Diagrammatic views of costal and mediastinal surfaces of isolated right and left lungs. Keywords: lungs, heart, anterior, lobe, diaphragm, pleural cavity, liver, bronchopulmonary segments, horizontal fissure, oblique fissure, apex, hilus, base, cardiac impression, primary bronchus, esophageal groove, pulmonary arteries Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Breathing Lungs are prevented from collapsing Intrapleural pressure is always slightly lower than the intrapulmonary pressure Inhaling is active work, exhaling is passive Human Anatomy, 3rd edition Prentice Hall, © 2001

Muscles Involved in Inspiration Diaphragm External intercostals Serratus anterior Pectoralis minor Sternocleidomastoid Human Anatomy, 3rd edition Prentice Hall, © 2001

Muscles Involved in Expiration Diaphragm Internal intercostals Abdominal muscles Involved in deep breathing Human Anatomy, 3rd edition Prentice Hall, © 2001