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Respiratory System. Respiration. 4 PROCESSES. Breathing External Respiration Internal Respiration Cellular Respiration. Trachea. epiglottis. thyroid cartilage. vocal cord. tracheal cartilages. The Trachea. posterior. esophagus. hyaline cartilage ring. lumen. Mucus membrane.
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Respiration 4 PROCESSES • Breathing • External Respiration • Internal Respiration • Cellular Respiration
Trachea epiglottis thyroid cartilage vocal cord tracheal cartilages
The Trachea posterior esophagus hyaline cartilage ring lumen Mucus membrane submucosa adventitia anterior
Vocal Cords • True vocal cords are inferior to false vocal cords • Sound is produced when expelled air is passing through the larynx over the vocal cords
mucus cilia Epithelial Lining of the Trachea
Alveoli alveolar macrophage type I alveolar cell O2 type II alveolar cell (surfactant secreting cell) CO2 pulmonary capillaries
Erythrocytes Function- transport respiratory gases Lack mitochondria. Why?
Hemoglobin- quaternary structure 2 chains and 2 chains Hemoglobin Structure 1 RBC contains 250 million hemoglobin molecules
Uptake of Oxygen by Hemoglobin in the Lungs O2 binds to hemoglobin to form oxyhemoglobin High Concentration of O2 in Blood Plasma High pH of the Blood Plasma oxyhemoglobin O2
Unloading of Oxygen from Hemoglobin in the Tissues When O2is releaseddeoxyhemoglobin Low Concentration of O2 in Blood Plasma Lower pH of the Blood Plasma
Carbon Dioxide Chemistry in the Blood CO2 + H2O H2CO3 HCO3- + H+ carbonic acid bicarbonate ion
Transport of Carbon Dioxide from the Tissues to the Lungs • 60-70% as bicarbonate dissolved in the • plasma (slow reaction) • 7-10% dissolved in the plasma as CO2 • 20-30% bound to hemoglobin as HbCO2 • CO2 + hemoglobin HbCO2
Mechanics of Breathing • 2 muscles involved with breathing: • external intercostal muscles • diaphragm • Breathing controlled by: • phrenicnerve from medulla • pons
Lung Ventilation 760 mm Hg 756 mm Hg Negative pressure draws air in Inspiration
Lung Ventilation Positive pressure forces air out 768 mm Hg Expiration
Lung Volumes Tidal Volume- 500 ml Vital Capacity- 4800 ml Residual Volume- 1000-1200ml Total Lung Capacity- 4400-6400ml IRV- 2800 ml ERV- 1000-1200ml Dead Space- 150 ml What factors affect lung volume?
pons medulla oblongata Regulation of Breathing phrenic CO2 and H+ triggers breathing reflex in medulla, not presence of O2 vegas
Restrictive vs Obstructive Air Flow • Restrictive- more diff. to get air in to lungs • Loss of lung tissue • Decrease in lungs ability to expand • Decrease in ability to transfer O2 and CO2 in blood • Diseases: • Fibrosis, sarcoidosis, muscular disease, chest wall injury, pneumonia, lung cancer, pregnancy, obesity • VC, TLC, RV, FRC
Restrictive vs Obstructive Air Flow • Obstructive- more diff. to get air out of lungs • Airway narrows • Increase in time it takes to empty lungs • Diseases: • Emphysema, chronic bronchitis, asthma VC, TLC, RV, FRC
Chronic Obstructive Pulmonary Diseases
COPD Chronic bronchitis- (obstructive) inhaled irritants lead to chronic excessive mucous production and inflammation and fibrosis of that mucosa; the amt of air that can be inhaled; use bronco- dilators and inhalers Emphysema- (obstructive and restrictive) enlargement of alveoli; alveolar tissue is destroyed resulting in fewer and larger alveoli; inefficient air exchange; smoker's disease; amt of air that can be exhaled Asthma- (obstructive disorder) cold, exercise, pollen and other allergens; from 1979-1989 the number of asthmatic deaths doubles
COPD Tuberculosis (TB)- (restrictive) infectious disease cause by bacterium Mycobacterium tuberculosis. Spread through air borne bacteria from infected person's cough. Total lung capacity declines Symptoms: fever night sweats, wt. loss, racking cough, and spitting up blood Polio- TLC declines (restrictive) Eliminated in U.S. and Western Hemisphere Still exists in Africa Lung cancer- promoted by free radicals and other carcinogens; very aggressive and metastasizes rapidly
Smoker’s lung Normal lung
Mammalian Dive Reflex • Heart rate slows • Blood flow to extremities constricted • Blood and water allowed to pass through organs and circulatory walls to chest cavity.
Hyperventilation • Short term, rapid, deep breathing beyond the need for the activity • Lowers the level of CO2 in blood
INQUIRY • Identify the lipoprotein molecule that reduces surface tension within the alveoli so they do not collapse during exhalation. • Even after the most forceful exhalation, a certain volume of air remains in the lungs. What is the volume of air called? • Describe the physical structure of alveoli. • What structures warm and moisten incoming air? • What body cavity are the lungs located? • What tissue lines the lungs? • What stimulates the breathing response? • Calculate total lung capacity given: • RV= 1000, TV = 500, ERV = 1100, IRV = 2500, VC= 4100