PHIS 206 1st Edition Lecture 16 Outline of Last Lecture I Circulation in the Heart II Heart Failure congestive III Shock IV Why Heart is Not Working Outline of Current Lecture I Respiratory System Functions II Respiration III Respiratory System Organization IV Mechanics of Respiration V Inspiration Expiration in Thorax VI How To Change Volume VII Pipes VIII Categories of Pulmonary Disorders IX La Passe s Law Current Lecture I II Respiratory System Functions allow you to exchange gasses carbon dioxide out oxygen in Secondary Functions cleanse warm and humidify air little capillary beds are exposed to air on one side alveoli important for speech helps water balance regulate body temperature Respiration use O2 and get rid of CO2 Includes ventilation breathing and the exchange of gasses in capillaries trachea alveoli spheres open on side bunches of grapes attached to bronchiole terminals lungs NOT SHOWN IN DIAGRAM bronchus bronchioles have muscles constrict and dilate These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Case of fluids flowing through pipes so usual laws apply Flow down Pressure up v Flow up and Resistance down Alveoli and respiratory bronchioles referred to as respiratory zone where gas change occurs Lungs have 2 sets of airways 1 conducting zone no exchange of gasses air moves 2 respiratory zone exchange of gasses occurs III Respiratory System Organization mucociliary system when cilia beats mucous moves up extension stroke pushes fluid up periodically swallow Function when air is brought in particles dust etc get stuck on the mucous and cilia moves fluid up 1st line of defense in alveoli IV Mechanics of Respiration air is a fluid and the conducting zone are pipes air goes down alveoli if the alveoli is at a lower pressure than the air need downhill pressure Thoracic cavity Abdominal cavity below V greater pressure difference greater flow pressure down if cavity expands pressure up if cavity volume down Lungs surrounded by a pleural membrane that separates them from a chest wall pleural membrane allows the lungs to expand and constrict pressure down when thoracic goes up and lungs expand alveoli pressure goes down so air will go in inspiration volume down pressure up lungs constrict alveoli pressure up so air will go out expiration Inspiration Expiration in Thorax air in thorax is always or less than atmospheric pressure 1 atm 760 mm Hg inhaling pressure down exhaling pressure not as in the thorax When below atmospheric pressure it stays there WHY elasticity of the lungs forces out when muscles relax VI VII VIII IX o elastic wall will make lungs collapse but air tight box stops it with the pressure outside o La Place s Law if you make spheres with openings smaller sphere equals greater pressure inside of it increase pressure in alveoli air will be injected and alveoli will get small Balloons small and big connected by glass rode air will go to the bigger one How To Change Volume At rest inspire by contracting diaphragm causes reduction in volume in thoracic cavity and increase in pressure When walking we increase air in and out by contracting the diaphragm and contracting internal and external intercostals external intercostal raises the ribs and expands the thorax When running we increase air in and out by contracting the diaphragm and external intercostal muscles increase activity by increasing contraction of intercostal muscles change volume of lungs by increasing the contracting muscles Decrease volume by contracting abdominal muscles Pipes Increase diameter by 16 inches then the pressure is reduced by 1 16th Category of Pulmonary Disorders Bronchioles have ability to change air resistance Two Categories 1 Obstructive disorders diameter decreases obstruction of airway Asthma o bronchiole smooth muscles contractions and airway resistance increases so need to use muscles to exhale NOT NORMAL o We use 3 5 caloric intake and asthmatics use 30 to breathe o Expiration is hard for them so effort needed to expire air bronchioles constricting pressure on lungs when exhale bronchioles reduce in size Symptoms wheezing sound of air 2 Restrictive disorders lung volume decreased Example pneumonia o pneumonia fluid accumulates in alveoli La Passe s Law resistance of surface tension in air liquid interphase surface tension is why spheres collapse pulmonary surfactant reduce surface tension between 2 phases Ex detergent our lung detergent pulmonary surfactant prevents alveoli from collapsing
View Full Document
Unlocking...