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Respiratory System Ch 23.

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Presentation on theme: "Respiratory System Ch 23."— Presentation transcript:

1 Respiratory System Ch 23

2 Breathing (Pulmonary Ventilation) External Respiration
4 PROCESSES Breathing (Pulmonary Ventilation) External Respiration Internal Respiration Cellular Respiration

3 Sinus Cavity act as resonance chambers for speech
mucosa warms and moistens the incoming air lightens facial bones

4 Pharynx Connects nasal cavity and mouth to larynx and esophagus
1)     nasopharynx- air passage pharyngotympanic (auditory) tube- allows middle air pressure to become equalized to atmospheric pressure Adenoids (pharyngeal) tonsils- mass of lymphoid tissue traps and destroys pathogens produces lymphocytes helps fight infection 2)     oropharynx- serves as a common conduit for air and food palatine and lingual tonsils 3)     laryngopharynx- accommodates both ingested food and air located at junction where tracheae and esophagus splits continuous with esophagus

5 Pharynx Epiglottis- flexible elastic cartilage
attached to the wall of the pharynx near the base of the tongue it closes the glottis in the respiratory tract (trachea) when food is swallowed Larynx- voice box; thyroid cart. that attaches to hyoid bone superior and cricoid inferior Provides open airway Junction for food and air Voice production


7 Olfactory epithelium Olfactory tract Olfactory bulb Nasal conchae Route of inhaled air

8 Trachea 16 C-shaped rings of hyaline cartilage (thyroid +cricoid + tracheal cartilage's, includes epiglottis (elastic cart) make up larynx Laryngitis- inflammation of the vocal cords resulting in inability to speak; due to voice overuse, very dry air, bacterial infection, and inhalation of irritating chemicals Trachea- held open by rings of hyaline cartilage, so it won't collapse during pressure changes when breathing.

9 Trachea

10 Epithelial Lining of the Trachea
mucus cilia

11 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

12 Lungs

13 Alveoli

14 Alveoli

15 Alveoli

16 Thoracic Cavity

17 Thoracic Cavity

18 Partial Pressure Gradients

19 Ventilation-Perfusion Coupling

20 Mechanics of Breathing
2 muscles involved with breathing: external intercostal muscles diaphragm Breathing controlled by: phrenic nerve from medulla pons

21 Lung Ventilation Negative pressure draws air in Inspiration 760 mm Hg

22 Lung Ventilation Positive pressure forces air out 768 mm Hg Expiration

23 Lung Volumes Tidal Volume- 500 ml Vital Capacity- 4800 ml
Residual Volume ml Total Lung Capacity ml IRV ml ERV ml Dead Space- 150 ml TV- tidal volumes- normal breathing ~500 ml air IRV- inspiratory reserve volume- amount of air that can be forcefully inhaled after a normal tidal volume inhalation ~3100 ml ERV- expiratory reserve volume- amount of air that can be forcefully exhaled after a normal tidal volume of exhalation ~1200 ml VC- vital capacity- total amount of exchangeable air; maximum amount of air that can be forcefully exhaled after a maximal inspiration ml VC=TV + IRV +ERV RV- residual volume = air that helps keep alveoli open and prevents lung from collapsing ~1200 ml TLC- total lung capacity = TV+IRV+ERV+RV Dead space- air that never contributes to gas exchange ~ conduit ~150 ml; throat, alveoli, nasal passage What factors affect lung volume?


25 What happens to TV, IRV, ERV, & VC during exercise?
IRV and ERV  TLC and VC- doesn't change

26 Breathing Centers in the Brain


28 Regulation of Breathing
medulla oblongata pons phrenic CO2 and H+ triggers breathing reflex in medulla, not presence of O2 vagus



31 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

32 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

33 Chronic Obstructive Pulmonary Diseases

34 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 the number of asthmatic deaths doubles

35 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

36 Smoker’s lung Normal lung

37 Dalton's Law of Partial Pressure
The total pressure of a gas exerted by a mixture of gas is the sum of the gases exerted independently. Air % partial pressure (mm Hg) N O CO H2O Total Dalton's law states that the individual gases of any gas mixture will have the same pressure alone or as part of the mixture. Thus, at sea level, the oxygen component of air by itself will support a mercury column mm high, and the nitrogen component will support a mercury column mm high. At depth all pressures increase, for both air as a mixture and for its component gases. For example, a doubling of ambient air pressure, which occurs at just 33 fsw, will double the partial pressure of oxygen, nitrogen, and other component gases. At 66 fsw, the ambient pressure is tripled, along with the partial pressure of oxygen, nitrogen and other gases inhaled at that depth. Partial pressure is directly related to its % in the total gas mixture. E.g., at 1 atm PO2 = 159 mm Hg

38 Henry's Law When a mixture of gas is in contact w/a liquid, each gas will dissolve in the liquid in proportion to its partial pressure. Gasses can go in and out of solution e.g., open soda, get CO2 bubbles (CO2 is under pressure)

39 Decompression Sickness
It is caused when N2 enters the blood circulation and the tissues. When extra N2 leaves the tissues, large bubbles form. N2 bubbles can travel throughout the system and into the lungs and blood routes. Treatment: hyperbaric chamber The increased pressure of each gas component at depth means that more of each gas will dissolve into the blood and body tissues, a physical effect predicted by Henry's Law. To review, Henry's law states that the amount of gas dissolving into any liquid or tissue with which it is in contact is proportional to the partial pressure of that gas. Inhaled gases are in close contact with blood entering the lungs. Hence, the greater the partial pressure of any inhaled gas, the more that gas will diffuse into the blood. Together, Boyle's and Henry's laws explain why, as a diver descends while breathing compressed air: 1) inhaled PO2 and PN2 increase and 2) the amount of nitrogen and oxygen entering the blood and tissues also increase.

40 Erythrocytes Function- transport respiratory gases
Lack mitochondria. Why?

41 Hemoglobin Structure Hemoglobin- quaternary structure
2  chains and 2  chains Hemoglobin Structure 1 RBC contains 250 million hemoglobin molecules

42 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

43 O2 pickup CO2 release

44 Unloading of Oxygen from Hemoglobin in the Tissues
When O2 is releaseddeoxyhemoglobin Low Concentration of O2 in Blood Plasma Lower pH of the Blood Plasma

45 O2 release CO2 pickup

46 Carbon Dioxide Chemistry in the Blood
CO2 + H2O  H2CO3  HCO H+ bicarbonate ion carbonic acid enzyme = carbonic anhydrase

47 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

48 Haldane Effect Haldane Effect- the amt of CO2 transported in the blood is markedly affected by the degree of oxygenation of the blood The lower the P02 and hemoglobin saturation w/O2, the more CO2 that can be carried by the blood

49 Carbon Monoxide Poisoning
CO poisoning (hypoxemia hypoxia) CO binds 200x more readily w/hemoglobin acts as a competitive inhibitor symptoms: cherry red lips, confused, headache does not produce characteristic signs of hypoxia (cyanosis and respiratory distress) treatment: hyperbaric chamber

50 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

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