260 likes | 288 Views
Chapter 23, part 4. The Respiratory System. SECTION 23-9 Gas Pickup and Delivery. Blood in peripheral capillaries delivers O 2 and absorbs CO 2. Reactions are completely reversible. Figure 23.20 An Overview of Respiratory Processes and Partial Pressures in Respiration. PLAY.
E N D
Chapter 23, part 4 The Respiratory System
Blood in peripheral capillaries delivers O2 and absorbs CO2 • Reactions are completely reversible
Figure 23.20 An Overview of Respiratory Processes and Partial Pressures in Respiration PLAY Animation: Respiratory Processes and Partial Pressures in Respiration Figure 23.20a, b
Oxygen transport • Carried mainly by RBCs, bound to hemoglobin • The amount of oxygen hemoglobin can carried is dependent upon: • PO2 • pH • temperature • BPG • Fetal hemoglobin has a higher O2 affinity than adult hemoglobin
Figure 23.21 The Oxygen-Hemoglobin Saturation Curve Figure 23.21
Figure 23.21 The Oxygen-Hemoglobin Saturation Curve Figure 23.21
Figure 23.22 The Effect of pH and Temperature on Hemoglobin Saturation Figure 23.22a, b
Figure 23.23 A Functional Comparison of Fetal and Adult Hemoglobin Figure 23.23
Carbon dioxide transport • 7% dissolved in plasma • 70% carried as carbonic acid • buffer system • 23% bound to hemoglobin • carbaminohemoglobin • Plasma transport
Figure 23.24 Carbon Dioxide Transport in Blood Figure 23.24
Figure 23.24 Carbon Dioxide Transport in Blood Figure 23.24
Summary of gas transport • Driven by differences in partial pressure • Oxygen enters blood at lungs and leaves at tissues • Carbon dioxide enters at tissues and leaves at lungs PLAY Animation: Gas Exchange and Gas Transport
Figure 23.25 A Summary of the Primary Gas Transport Mechanisms Figure 23.25a, b
Gas absorption/generation balanced by capillary rates of delivery/removal • Homeostatic mechanisms maintain balance • Local regulation of gas transport and alveolar function include • Lung perfusion • Alveolar capillaries constrict in low oxygen • Alveolar ventilation • Bronchioles dilate in high carbon dioxide
Respiratory centers of the brain • Medullary centers • Respiratory rhythmicity centers set pace • Pons • Apneustic and pneumotaxic centers
Figure 23.27 Respiratory Centers and Reflex Controls Figure 23.27
Respiratory reflexes • Respiratory centers are modified by sensory information including • Chemoreceptor reflexes • Level of carbon dioxide • Baroreceptors reflexes • Hering-Breuer reflexes • Prevents overinflation • Protective reflexes
Figure 23.28 The Chemoreceptor Response to Changes in PCO2 Figure 23.28
Voluntary control of respiration • Regulation of respiratory rate is dependent upon: • Conscious and unconscious thought • Emotional state • Anticipation PLAY Animation: Control of Respiration
Neonatal Respiration • Upon taking the first breath: • Inhaled air enters the respiratory passages for the first time • The bronchial tree and most of the alveoli are inflated • Subsequent breaths complete inflation of the alveoli
The efficiency of the respiratory system decreases with age as: • Elastic tissue deteriorates causing lower lung compliance and vital capacity • Chest movements are restricted by arthritic changes • Some degree of emphysema normally occurs
You should now be familiar with: • The primary functions of the respiratory system • The organs of the respiratory system and their functions • The processes of external and internal respiration • The physical principles governing the movement of air into the lungs and the diffusion of gases into the blood • The important structural features of the respiratory membrane • How oxygen and carbon dioxide are picked up, transported and released in the blood