School of Medicine SUNYAB PGY452 Respiratory Lectures April 2 2015 Daniel D Swartz Ph D Lecture 8 Disease and Environmental Effects on Respiration Reading Assignment Berne Levy Overview of Chapters 20 24 Chronic Obstructive Pulmonary Disease COPD air exchange is impaired due to narrowing of the airways Cause smoking Pulmonary Artery Deoxygenated Pulmonary Vein Chronic Bronchitis bluish tinge to skin color Oxygenated over weight excessive mucus production general inflammation of entire respiratory tract Emphysema normal pink skin coloration thin breathe shallow rapid breaths loss of elastin and elastic recoil ofdifficulty in exhalation work to exhale Cover 80 90 alveolar surface Figure 17 2f Pulmonary Blood Flow Pulmonary blood volume 0 5L 10 total Pulmonary capillary volume 75 mL Pulmonary blood pressure 25 8 mmHg Congestive Heart Failure CHF Poor Left Ventricular Heart Function Blood pools in pulmonary circulation Increase pulmonary pressure Pulmonary edema Interstitial fluid Shortness of breath and blood in phlegm PPHN an example of pulmonary vascular lung disease Cystic Fibrosis genetic disease poor chloride transport in epithelial cells Airway humidifies warms and filters air as it passes toward alveoli Cigarette smoking paralyzes cilia in the airway cough Figure 17 8 Flow Patm Palv R Inhalation Poiseuille s law R L r4 Active Muscle Disease PA neg Myasthenia Gravis Guillain Barre Syndrome Polio 1 5 cm R 1 r4 Resistance can be controlled by Constrictors or dilators Histamine CO2 Diaphragm 60 75 of volume Rib cage 25 40 Figure 17 9b Figure 17 12 Overview Compliance and Elastance Compliance ability of the lung to stretch effects work of breathing Restrictive lung disease reduces compliance of the lung Fibrotic Lung Disease inelastic scar tissue in lung Respiratory Distress Syndrome lack of surfactant in the lung Compliance V P Emphysema High Compliance V RDS and Fibrosis Low Compliance P Elastance ability of the lung to recoil back to resting volume Emphysema reduces elastance of the lung Surfactant mixture of phospholipids and proteins secreted by alveolar type II cells Smaller alveoli have a higher concentration of surfactant Therefore equalizing the resistance to inflation Figure 17 13b Figure 17 13 Overview Liquid Ventilation Poiseuille s Law R L r4 Breathing through a straw or a garden hose Length Viscosity Radius Table 17 3 Pulmonary and Alveolar Ventilation How we breath affects oxygenation Total Pulmonary Ventilation minute volume Minute volume vent rate X tidal volume 12 breaths min X 500 mL breath 6000 mL min 6 L min Anatomic Dead Space 150 mL Alveolar Ventilation vent rate X TV dead space 12 breaths min X 500 mL min 150mL 4200mL min 4 2 L min If TV were 150 ml and rate of 40 breaths min Tachypnea what would the Alveolar ventilation be Table 17 4 Why do some have sleep apnea Table 17 5 Effect of Environment Altitude Atmospheric pressure Hypoxia Altered gas mixtures Table 17 7 Right to Left Anatomic Shunt Right to Left Anatomic Shunt A Normal carotid and bronchial circ B Abnormal atrial septal defect Fig 22 12 B L Po2 is determined by atmospheric pressure and alveolar ventilation Figure 18 4a Reduced surface area Hypoxia and Hypercarbia Figure 18 4b Thickened alveolar membrane Figure 18 4c Increased diffusion distance Figure 18 4d Low O2 vasoconstrict Low CO2 further brochiole constrict Increased airway resistance Figure 18 4e Figure 18 4 Overview High altitude causes chronic hypoxia resulting in increased production of erythrocytes erythropoietin which in turn increase the viscosity of the blood This slows the blood flow Figure 18 8 Overview Metabolic Acidosis Exercise Exercise Respiratory Alkalosis Fever Hyperventilation Atmospheric Heat Hypoventilation Respiratory Acidosis Figure 18 10 Overview 2 3 DPG is made from an intermediate of the glycolysis pathway 2 3 diphosphoglycerate Chronic hypoxia triggers RBC production of 2 3 DPG shift of curve to the right Also high altitude anemia Figure 18 11 Blood Loss Anemia Respiratory Disease Figure 18 13 1 Pons 2 VRG 3 Medullary chemoreceptor 4 Sensory neuron 5 Carotid chemoreceptor 6 Somatic motor neuron expiration 7 Aortic chemoreceptor 8 Internal intercostals 9 Abdominal muscles 10 Diaphragm 11 External intercostals 12 Scalenes sternocleidmastoids 13 Somatic motor neuron inspiration 14 DRG 15 Limbic system 16 Higher brain centers emotions voluntary control Maintains upper airway open Figure 18 16 Diving Depth Increased Atmospheric Pressure Increased airway Resistance Increased Dead Space Increased Viscosity Snorkel Emotions parasympathetic Breath Holding High Altitude Hypoxia Pulmonary Edema HAPE Pulmonary arteriole vasoconstriction Increased Erythrocytes Hyperventilation Alkalosis Increase pH
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