3Sinus Cavity act as resonance chambers for speech mucosa warms and moistens the incoming airlightens facial bones
4Pharynx Connects nasal cavity and mouth to larynx and esophagus 1) nasopharynx- air passagepharyngotympanic (auditory) tube- allows middle air pressure to become equalized to atmospheric pressureAdenoids (pharyngeal) tonsils- mass of lymphoid tissuetraps and destroys pathogensproduces lymphocyteshelps fight infection2) oropharynx- serves as a common conduit for air and foodpalatine and lingual tonsils3) laryngopharynx- accommodates both ingested food and airlocated at junction where tracheae and esophagus splitscontinuous with esophagus
5Pharynx Epiglottis- flexible elastic cartilage attached to the wall of the pharynx near the base of the tongueit closes the glottis in the respiratory tract (trachea) when food is swallowedLarynx- voice box; thyroid cart. that attaches to hyoid bone superior and cricoid inferiorProvides open airwayJunction for food and airVoice production
7OlfactoryepitheliumOlfactory tractOlfactory bulbNasalconchaeRoute ofinhaled air
8Trachea16 C-shaped rings of hyaline cartilage (thyroid +cricoid + tracheal cartilage's, includes epiglottis (elastic cart) make up larynxLaryngitis- inflammation of the vocal cords resulting in inability to speak; due to voice overuse, very dry air, bacterial infection, and inhalation of irritating chemicalsTrachea- held open by rings of hyaline cartilage, so it won't collapse during pressure changes when breathing.
20Mechanics of Breathing 2 muscles involved with breathing:external intercostal musclesdiaphragmBreathing controlled by:phrenic nerve from medullapons
21Lung Ventilation Negative pressure draws air in Inspiration 760 mm Hg
22Lung VentilationPositive pressure forces air out768 mm HgExpiration
23Lung Volumes Tidal Volume- 500 ml Vital Capacity- 4800 ml Residual Volume mlTotal Lung Capacity mlIRV mlERV mlDead Space- 150 mlTV- tidal volumes- normal breathing ~500 ml airIRV- inspiratory reserve volume- amount of air that can be forcefully inhaled after a normal tidal volume inhalation ~3100 mlERV- expiratory reserve volume- amount of air that can be forcefully exhaled after a normal tidal volume of exhalation ~1200 mlVC- vital capacity- total amount of exchangeable air; maximum amount of air that can be forcefully exhaled after a maximal inspiration mlVC=TV + IRV +ERVRV- residual volume = air that helps keep alveoli open and prevents lung from collapsing ~1200 mlTLC- total lung capacity = TV+IRV+ERV+RVDead space- air that never contributes to gas exchange ~ conduit ~150 ml; throat, alveoli, nasal passageWhat factors affect lung volume?
31Restrictive vs Obstructive Air Flow Restrictive- more diff. to get air in to lungsLoss of lung tissueDecrease in lungs ability to expandDecrease in ability to transfer O2 and CO2 in bloodDiseases:Fibrosis, sarcoidosis, muscular disease, chest wall injury, pneumonia, lung cancer, pregnancy, obesity VC, TLC, RV, FRC
32Restrictive vs Obstructive Air Flow Obstructive- more diff. to get air out of lungsAirway narrowsIncrease in time it takes to empty lungsDiseases:Emphysema, chronic bronchitis, asthma VC, TLC, RV, FRC
34COPDChronic 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 inhalersEmphysema- (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 exhaledAsthma- (obstructive disorder) cold, exercise, pollen and other allergens; from the number of asthmatic deaths doubles
35COPDTuberculosis (TB)- (restrictive) infectious disease cause by bacterium Mycobacterium tuberculosis. Spread through air borne bacteria from infected person's cough. Total lung capacity declinesSymptoms: fever night sweats, wt. loss, racking cough, and spitting up bloodPolio- TLC declines (restrictive)Eliminated in U.S. and Western HemisphereStill exists in AfricaLung cancer- promoted by free radicals and other carcinogens; very aggressive and metastasizes rapidly
37Dalton'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)NOCOH2OTotalDalton'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
38Henry's LawWhen 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 solutione.g., open soda, get CO2 bubbles (CO2 is under pressure)
39Decompression 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 chamberThe 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 and2) the amount of nitrogen and oxygen entering the blood and tissues also increase.
40Erythrocytes Function- transport respiratory gases Lack mitochondria. Why?
41Hemoglobin Structure Hemoglobin- quaternary structure 2 chains and 2 chainsHemoglobin Structure1 RBC contains 250 million hemoglobin molecules
42Uptake of Oxygen by Hemoglobin in the Lungs O2 binds to hemoglobin to form oxyhemoglobinHigh Concentration of O2 in Blood PlasmaHigh pH of the Blood Plasma
46Carbon Dioxide Chemistry in the Blood CO2 + H2O H2CO3 HCO H+bicarbonateioncarbonicacidenzyme = carbonic anhydrase
47Transport of Carbon Dioxide from the Tissues to the Lungs 60-70% as bicarbonate dissolved in theplasma (slow reaction)7-10% dissolved in the plasma as CO220-30% bound to hemoglobin as HbCO2CO2 + hemoglobin HbCO2
48Haldane EffectHaldane Effect- the amt of CO2 transported in the blood is markedly affected by the degree of oxygenation of the bloodThe lower the P02 and hemoglobin saturation w/O2, the more CO2 that can be carried by the blood
49Carbon Monoxide Poisoning CO poisoning (hypoxemia hypoxia)CO binds 200x more readily w/hemoglobinacts as a competitive inhibitorsymptoms: cherry red lips, confused, headachedoes not produce characteristic signs of hypoxia (cyanosis and respiratory distress)treatment: hyperbaric chamber
50INQUIRYIdentify 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