<a href="/keyword/respiratory-system/" >respiratory system</a> OBJECTIVES: Brief anatomy overview Discuss the mechanics of pulmonary ventilation Note several important clinical measurements of ventilation Describe the exchange of respiratory gases between air and blood Gas pressures Describe the transport of respiratory gases via blood Briefly list several mechanisms of respiratory control <a href="/keyword/respiratory-system/" >respiratory system</a> Quick breakdown Upper <a href="/keyword/respiratory-system/" >respiratory system</a> Nose Nasal Cavity Sinuses Oral Cavity Pharynx Lower <a href="/keyword/respiratory-system/" >respiratory system</a> Larynx Trachea Bronchial Tree Alveoli Respiratory Anatomy Upper <a href="/keyword/respiratory-system/" >respiratory system</a> Respiratory Anatomy Lower <a href="/keyword/respiratory-system/" >respiratory system</a> LARYNX LARYNX Respiratory Anatomy Lower <a href="/keyword/respiratory-system/" >respiratory system</a> LARYNX LARYNX * Vocal fold = vocal ligament Respiratory Anatomy Lower <a href="/keyword/respiratory-system/" >respiratory system</a> - TRACHEA Respiratory Anatomy Lower <a href="/keyword/respiratory-system/" >respiratory system</a> BRONCHI ALVEOLI Respiratory Anatomy Lower <a href="/keyword/respiratory-system/" >respiratory system</a> ALVEOLI (air sacs) Respiratory Anatomy Lower <a href="/keyword/respiratory-system/" >respiratory system</a> - LUNGS Respiratory Anatomy Lower <a href="/keyword/respiratory-system/" >respiratory system</a> PARIETAL PLURA Respiratory Anatomy Lower <a href="/keyword/respiratory-system/" >respiratory system</a> PARIETAL PLURA Respiratory Anatomy Lower <a href="/keyword/respiratory-system/" >respiratory system</a> VISCERAL PLURA PLURAL SPACE (filled with fluid) Respiratory Anatomy Pleural Membranes clinical issues NORMAL PLEURITIS / PLEURISY Respiratory Anatomy Pleural Membranes clinical issues PNEUMOTHORAX Atelectasis (Collapsed Lung) secondary to air/blood/excess fluid invading pleural space Respiratory Anatomy Pleural Membranes clinical issues PNEUMOTHORAX (Collapsed Lung) WARNING!!! GRAPHIC IMAGE IN NEXT SLIDE! Respiratory Anatomy Pleural Membranes clinical issues PNEUMOTHORAX (Collapsed Lung) Respiratory Physiology 1. Pulmonary Ventilation - Getting air into/out of lungs 2. Exchange of Respiratory Gases - Diffusion of O2 from air to blood - Diffusion of CO2 from blood to air Respiratory Physiology Pulmonary Ventilation Driving force for air flow is PRESSURE Alter pressure by changing VOLUME OF LUNGS Boyle's Law pressure of gas inversely proportional to volume of container Respiratory Physiology Pulmonary Ventilation Driving force for air flow is PRESSURE Alter pressure by changing VOLUME OF LUNGS Boyle's Law pressure of gas inversely proportional to volume of container NOTE: Compliance (elasticity) of the lungs must be good for this mechanism to work well Respiratory Physiology Pulmonary Ventilation Driving force for air flow is PRESSURE Alter pressure by changing VOLUME OF LUNGS Boyle's Law pressure of gas inversely proportional to volume of container Respiratory Physiology Pulmonary Ventilation Important Measurements VOLUMES 2a. 4. 1. 5. 7. 2b. 6. 3. Respiratory Physiology Pulmonary Ventilation Important Measurements RATE VE (Respiratory Min. Vol.) = VT (Tidal Vol.) X avg VE (Breaths per Min) = 500ml/breath X 12 breaths/min = 6L/min * don't work about VA (alveolar ventilation) for this class Respiratory Physiology Exchange of Respiratory Gases between air and blood Respiratory Physiology Exchange of Respiratory Gases between air and blood IT'S ALL ABOUT PRESSURE! 1. Pressure of O2 in air of alveolus vs. in blood 100mmHg = PARTIAL PRESSURE in air of lung 40mmHg = PARTIAL PRESSURE in blood going to lung Respiratory Physiology Exchange of Respiratory Gases between air and blood IT'S ALL ABOUT PRESSURE! 1. Pressure of O2 in air of alveolus vs. in blood 100mmHg = PARTIAL PRESSURE in air of lung 40mmHg = PARTIAL PRESSURE in blood going to lung 2. Pressure of CO2 in blood vs. in air of alveolus 40mmHg = PARTIAL PRESSURE in air of lung 45mmHg = PARTIAL PRESSURE in blood going to lung Respiratory Physiology Exchange of Respiratory Gases between blood and tissues IT'S ALL ABOUT PRESSURE! 1. Pressure of O2 in blood vs. in tissue fluid 95mmHg = PARTIAL PRESSURE in blood 40mmHg = PARTIAL PRESSURE in tissue fluid Respiratory Physiology Exchange of Respiratory Gases between blood and tissues IT'S ALL ABOUT PRESSURE! 1. Pressure of O2 in blood vs. in tissue fluid 95mmHg = PARTIAL PRESSURE in blood 40mmHg = PARTIAL PRESSURE in tissue fluid 2. Pressure of CO2 in blood vs. in tissue fluid 40mmHg = PARTIAL PRESSURE in blood 45mmHg = PARTIAL PRESSURE in tissue fluid Respiratory Physiology Transporting Respiratory Gases in blood O2 and CO2 don't like to hang around in plasma (technically speaking, they have limited &quot;solubility&quot; in plasma) Can be carried in blood by either binding to a carrier or by being transformed into another molecule OXYGEN Binds to hemoglobin in RBC's CO2 Combined with water to make an acid called CARBONIC ACID This acid then breaks up into a H+ ion and a BICARBONATE ion Respiratory Physiology Transporting Respiratory Gases in blood OXYGEN Binds to hemoglobin in RBC's Respiratory Physiology Transporting Respiratory Gases in blood OXYGEN Oxygen Saturation Curve shows % total heme units in blood that have O2 bound to them at a given partial pressure of O2 in blood 95mmHg partial pressure 97% saturation Respiratory Physiology Transporting Respiratory Gases in blood CARBON DIOXIDE Most (70%) chemically converted into something that can travel in plasma First, combined with water (H2O) to make CARBONIC ACID (H2CO3) This is accomplished by an enzyme called CARBONIC ANHYDRASE Then that spontaneously breaks up into H+ and BICARBONATE (HCO3-) BICARB. transported into plasma, H+ binds to hemoglobin Some (23%) binds to hemoglobin Small amount (7%) dissolves in plasma Control of Respiration Major control centers are in medulla and pons MEDULLA Rhythmicity Centers PONS Pneumotaxic / Apneustic Centers Control of Respiration Major control centers are in medulla and pons MEDULLA Rhythmicity Centers Divided into Dorsal Resp. Group (DRG) and Ventral Resp. Group (VRG) Peripheral Chemoreceptors Resp. Rhythmicity Centers DRG (has built-in chemoreceptors to monitor CSF) VRG To muscles of inspiration (diaphragm and external intercostals) Control of Respiration Chemoreceptors Mainly concerned with CO2 levels and pH in arterial blood and CSF Also monitor O2 levels of blood and CSF Hypercapnia increased blood CO2 stimulates incr output from DRG, increased rate and depth of breathing Hypocapnia decreased blood CO2 stimulates decr output from DRG, decreased rate and depth of breathing Acidosis too low blood pH (below ~ 7.3) stimulates incr output from DRG, increased rate and depth of breathing Alkalosis too high blood pH (above ~7.5) stimulates decr output from DRG, decreased rate and depth of breathing