Anatomy-of-the-Respiratory-System.pdf

Chapter 6 Respiratory System See separate PowerPoint slides for all figures and tables pre- inserted into PowerPoint without notes. Copyright © McGraw-Hill Education. Permission required for reproduction or display. 1 Copyright © McGraw-Hill Educat...

Chapter 6 Respiratory System See separate PowerPoint slides for all figures and tables pre- inserted into PowerPoint without notes. Copyright © McGraw-Hill Education. Permission required for reproduction or display. 1 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Functions 1. Gas exchange 2. Regulation of blood pH 3. Voice Production 4. Olfaction 5. Innate Immunity 6. Ventilation Copyright © McGraw-Hill Education. Permission required for reproduction or display. Upper Respiratory Tract External nose Nasal cavity Pharynx Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Figure 15.1 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Nose External nose: composed of mainly of hyaline cartilage Nasal cavity: - extends from nares (nostrils) to choane - choane: openings to pharynx - hard palate is its roof Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Paranasal sinuses: - air filled spaces within bone - open into nasal cavity - lined with mucous Conchae: - on each side of nasal cavity - increase surface area of nasal cavity - help in cleaning, humidifying, warming of air Nasolacrimal ducts: - carry tears from eyes - open into nasal cavity Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Functions of Nose Filters Airway for respiration Involved in speech Olfactory receptors Warms air Sneezing dislodges materials from nose Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Pharynx Throat Common passageway for resp. and dig. systems Nasopharynx: takes in air Oropharynx: - extends from uvula to epiglottis - takes in food, drink, and air Laryngopharynx: - extends from epiglottis to esophagus - food and drink pass through Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Uvula: - “little grape” - extension of soft palate Pharyngeal tonsil: aids in defending against infections Copyright © McGraw-Hill Education. Permission required for reproduction or display.  11 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Lower Respiratory Tract Larynx Trachea Bronchi Lungs Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Figure 15.1 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Larynx In front of throat Consists of cartilage Thyroid cartilage: - largest piece of cartilage - called Adam’s apple Epiglottis: - piece of cartilage - flap that prevents swallowed materials from entering larynx Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Vocal folds/cords: - source of voice production - air moves past them, they vibrate, and sound is produced - force of air determine loudness - tension determines pitch Laryngitis: - inflammation of vocal folds - caused by overuse, dry air, infection Copyright © McGraw-Hill Education. Permission required for reproduction or display. Copyright © McGraw-Hill Education. Permission required for reproduction or display. Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Trachea Windpipe Consists of 16-20 C shaped pieces of cartilage Contains cilia pseudostratified columnar epi. Smoking kills cilia Coughing dislodges materials from trachea Divides into right and left primary bronchi (lungs) Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Bronchi Divide from trachea Connect to lungs Lined with cilia Contain C shaped pieces of cartilage Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Lungs Primary organ of respiration Cone shaped Rest on diaphragm Right lung has 3 lobes Left lung has 2 lobes Contains many air passageways (divisions) Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Air Passageways of Lungs 1. Primary bronchi 2. Lobar (secondary) bronchi 3. Segmental (tertiary) bronchi 4. Bronchioles 5. Terminal bronchioles 6. Respiratory bronchioles 7. Alveolar ducts 8. Alveoli Structures become smaller and more numerous from primary bronchi to alveoli Copyright © McGraw-Hill Education. Permission required for reproduction or display. Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Please update to 9e copyright for Figure 15.6 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Superior lobe Pulmonary arteries Hilum Hilum Primary bronchi Horizontal fissure Pulmonary Cardiac impression veins Middle lobe Cardiac notch Inferior lobe Oblique fissure Oblique fissure Right lung Left lung Medial views Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Lungs Continued Alveoli: - small air sacs - where gas exchange occurs - surrounded by capillaries - 300 million in lungs Asthma attack: contraction of terminal bronchioles leads to reduced air flow Copyright © McGraw-Hill Education. Permission required for reproduction or display. Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Respiratory Membrane In lungs where gas exchange between air and blood occurs Formed by walls of alveoli and capillaries Alveolar ducts and respiratory bronchioles also contribute Very thin for diffusion of gases Copyright © McGraw-Hill Education. Permission required for reproduction or display. Copyright © McGraw-Hill Education. Permission required for reproduction or display. Pleural Membranes and Cavities Pleura: double-layered membrane around lungs Parietal pleura: membrane that lines thoracic cavity Visceral pleura: membrane that covers lung’s surface Pleural cavity: space around each lung 28 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Ventilation What is it? - breathing - process of moving air in and out of lungs - uses diaphragm: skeletal muscle that separates thoracic and abdominal cavities 30 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Phases of Ventilation Inspiration: - breathe in - uses external intercostal muscles Expiration: - breathe out - uses internal intercostal muscles 31 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Copyright © McGraw-Hill Education. Permission required for reproduction or display. Pressure Changes and Air Flow When thoracic cavity volume increases pressure decreases. When thoracic cavity volume decreases pressure increases. Air flows from areas of high to low pressure. 33 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Inspiration Diaphragm descends and rib cage expands Thoracic cavity volume increases, pressure decreases Atmospheric pressure is greater than (high) alveolar pressure (low) Air moves into alveoli (lungs) 34 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Expiration Diaphragm relaxes and rib cage recoils Thoracic cavity volume decreases, pressure increases Alveolar pressure is greater than (high) atmospheric pressure (low) Air moves out of lungs 35 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Lung Recoil What is it? - tendency for an expanded lung to decrease in size - occurs during quiet expiration - due to elastic fibers and thin film of fluid lining alveoli Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Surfactant What is it? - mixture of lipoproteins - produced by secretory cells of alveoli - single layer on surface of thin fluid lining alveoli - reduces surface tension - keeps lungs from collapsing Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Pleural Pressure What is it? - pressure in pleural cavity - less than alveolar pressure - keep alveoli from collapsing Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Factors that Influence Pulmonary Ventilation Lung elasticity: - lungs need to recoil between ventilations - decreased by emphysema Lung compliance: - expansion of thoracic cavity - affected if rib cage is damaged Respiratory passageway resistance: occurs during an asthma attack, infection, tumor 40 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Pulmonary Volumes Spirometer: device that measures pulmonary volumes Tidal volume (TV): volume of air inspired and expired during quiet breathing Inspiratory reserve volume (IRV): volume of air that can be inspired forcefully after a normal inspiration 41 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Expiratory reserve volume (ERV): volume of air that can be expired forcefully after a normal expiration Residual volume (RV): volume of air remaining in lungs after a max. expiration (can’t be measured with spirometer) 42 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Vital Capacity (VC): - max. amount of air a person can expire after a max. inspiration VC = IRV + ERV + TV Total lung capacity (TLC): TLC = VC + RV Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Gas Exchange Respiratory membrane: - where gas exchange between blood and air occurs - primarily alveoli - some in respiratory bronchioles and alveolar ducts - does NOT occur in bronchioles, bronchi, trachea - influenced by thickness of membrane, total area of membrane, partial pressure of gases Copyright © McGraw-Hill Education. Permission required for reproduction or display. Respiratory Membrane Thickness Increased thickness decreases rate of diffusion Pulmonary edema decreases diffusion Rate of gas exchange is decreased O2 exchange is affected before CO2 because CO2 diffuse more easily than O2 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Surface Area Total surface area is 70 square meters (basketball court) Decreased due to removal of lung tissue, destruction from cancer, emphysema Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Partial Pressure What is it? - pressure exerted by a specific gas in a mixture of gases - Ex. Total pressure of all gases is 760 (mm Hg) and 21% of mixture is O2 then partial pressure for O2 is 160 mm Hg - symbol is P and gas (Po2) Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Diffusion of Gases in Lungs Cells in body use O2 and produce CO2. Blood returning from tissues and entering lungs has a decreased Po2 and increased Pco2 O2 diffuses from alveoli into pulmonary capillaries (blood) CO2 diffuses from capillaries into alveoli Copyright © McGraw-Hill Education. Permission required for reproduction or display. Copyright © McGraw-Hill Education. Permission required for reproduction or display. Diffusion of Gases in Tissues Blood flow from lungs through left side of heart to tissue capillaries Oxygen diffuses from capillaries into interstitial fluid because Po2 in interstitial fluid is lower than capillary Oxygen diffuses from interstitial fluid into cells (Po2) is less Copyright © McGraw-Hill Education. Permission required for reproduction or display. Copyright © McGraw-Hill Education. Permission required for reproduction or display. Carbon Dioxide Transport and Blood pH CO2 diffuses from cells into capillaries CO2 enters blood and is transported in plasma, comb. with blood proteins, bicarbonate ions CO2 reacts with water to form carbonic acid when forms H+ + bicarbonate ions Carbonic anhydrase (RBC) increases rate of CO2 reacting with water CO2 levels increase blood pH decreases Copyright © McGraw-Hill Education. Permission required for reproduction or display.