Respiratory System Duarte Ferreira, PhD Karolinka institutet, Department of Physiology and Pharmacology [email protected] Respiratory System Functions: • Provides for gas exchange • Helps regulate blood pH • Contains receptors for sense of smell, filters inspired air, produces vocal sounds, and excretes small amounts of water and heat Tortora GJ, Principles of Anatomy and Physiology Respiratory System Sherwood L, Human Physiology The nose As the air passes through the nose, it is warmed, filtered and moistened. Tortora GJ, Principles of Anatomy and Physiology Pharynx Tortora GJ, Principles of Anatomy and Physiology Larynx Tortora GJ, Principles of Anatomy and Physiology Vocal cords Abduction Adduction Tortora GJ, Principles of Anatomy and Physiology Bronchial tree Tortora GJ, Principles of Anatomy and Physiology Lungs Tortora GJ, Principles of Anatomy and Physiology Microscopy anatomy of the lungs Tortora GJ, Principles of Anatomy and Physiology Structural components of an alveolus Type I cells Main sites of gas exchange Type II cells Secrete alveolar surfactant Tortora GJ, Principles of Anatomy and Physiology Surfactant Type I cells Main sites of gas exchange Type II cells Secrete alveolar fluid Tortora GJ, Principles of Anatomy and Physiology Surfactant Boron & Boulpaep. Medical Physiology. Elsevier, 2016. Surfactant Type I cells Main sites of gas exchange Type II cells Secrete alveolar fluid Tortora GJ, Principles of Anatomy and Physiology Effect of pulmonary surfactant Sherwood L, Human Physiology Surfactant Elastic recoil Boron & Boulpaep. Medical Physiology. Elsevier, 2016. Muscles of inhalation and exhalation Tortora GJ, Principles of Anatomy and Physiology Muscles of inhalation and exhalation Sherwood L, Human Physiology Muscles of inhalation and exhalation Sherwood L, Human Physiology Muscles of inhalation and exhalation Sherwood L, Human Physiology Inhalation and expiration Boyle’s law Sherwood L, Human Physiology Pressures important in ventilation Sherwood L, Human Physiology Pressure changes in pulmonary respiration Tortora GJ, Principles of Anatomy and Physiology Changes in lung volumes Sherwood L, Human Physiology Changes in lung volumes Sherwood L, Human Physiology Adjustment between ventilation and perfusion Sherwood L, Human Physiology Adjustment between ventilation and perfusion Sherwood L, Human Physiology Lung volumes and capacities Tortora GJ, Principles of Anatomy and Physiology Lung volumes and capacities Changes in O2 and CO2 pressure Concept of partial pressure Sherwood L, Human Physiology Changes in O2 and CO2 pressure Sherwood L, Human Physiology Changes in O2 and CO2 pressure Tortora GJ, Principles of Anatomy and Physiology Factors affecting gas transfer Sherwood L, Human Physiology Transport of O2 and CO2 Tortora GJ, Principles of Anatomy and Physiology Oxygen-hemoglobin dissociation curve Tortora GJ, Principles of Anatomy and Physiology Oxygen-hemoglobin dissociation curve As the pH decreases, the affinity of hemoglobin for O2 declines so less O2 combines with hemoglobin and more is available to tissues. Tortora GJ, Principles of Anatomy and Physiology Oxygen-hemoglobin dissociation curve As the PCO2 increases, the affinity of hemoglobin for O2 declines so less O2 combines with hemoglobin and more is available to tissues. Tortora GJ, Principles of Anatomy and Physiology Oxygen-hemoglobin dissociation curve As temperature increases, the affinity of hemoglobin for O2 decreases. Tortora GJ, Principles of Anatomy and Physiology Oxygen-hemoglobin dissociation curve As the concentration of 2,3-diphosphoglycerate (DPG) increases, the affinity of hemoglobin for O2 decreases. Tortora GJ, Principles of Anatomy and Physiology Carbon dioxide transport Tortora GJ, Principles of Anatomy and Physiology CO2 transport to alveolus Tortora GJ, Principles of Anatomy and Physiology CO2 transport from tissue Tortora GJ, Principles of Anatomy and Physiology Summary of O2 and CO2 transport Sherwood L, Human Physiology Control of breathing Factors affecting airway resistance Sherwood L, Human Physiology Respiratory centre Tortora GJ, Principles of Anatomy and Physiology Normal breathing Tortora GJ, Principles of Anatomy and Physiology Forced breathing Tortora GJ, Principles of Anatomy and Physiology Central chemoreceptor Hypoventilation and hyperventilation Sherwood L, Human Physiology Peripheral chemoreceptors Sensitive to changes in: - PO2 - H+ - PCO2 Aortic bodies à Vagus (X) nerves Carotid bodies à Glossopharyngeal (IX) nerves Tortora GJ, Principles of Anatomy and Physiology Influence of Chemical Factors on Respiration Sherwood L, Human Physiology Regulation of breathing Sherwood L, Human Physiology Regulation of breathing Tortora GJ, Principles of Anatomy and Physiology Influence of Chemical Factors on Respiration.