chapter 18, part a
DESCRIPTION
Chapter 18, part A. Gas Exchange and Transport. About this Chapter. Getting CO 2 & O 2 dissolved for transport How oxygen is transported, role of hemoglobin How carbon dioxide is transported Regulators that sense and coordinate respiration with circulation for gas transport. - PowerPoint PPT PresentationTRANSCRIPT
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Dee Unglaub Silverthorn, Ph.D.
HUMAN PHYSIOLOGY
PowerPoint® Lecture Slide Presentation byDr. Howard D. Booth, Professor of Biology, Eastern Michigan University
AN INTEGRATED APPROACH
T H I R D E D I T I O N
Chapter 18, part AGas Exchange and Transport
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
About this Chapter
• Getting CO2 & O2 dissolved for transport • How oxygen is transported, role of
hemoglobin• How carbon dioxide is transported• Regulators that sense and coordinate
respiration with circulation for gas transport
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Overview of Respiratory Exchange
Figure 18-1: Overview of oxygen and exchange and Transport CO2
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
• Pressure gradient: lower at high altitudes• Temperature: constant in warm blooded
humans• Solubility (solute & solvent): O2 or CO2 in
water
Solubility of Gasses
Figure 18-2: Gases in solution
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Gas Exchange in the Lungs and Tissues: Oxygen
• Diffusion through alveolar thin cells• Down diffusion gradient
• Higher in alveoli• Lower in blood
• Diffusion from blood • Also down gradient• To ECF• To tissue cells (convert O2 to CO2)
PLAY Animation: Respiratory System: Gas Exchange
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Gas Exchange in the Lungs and Tissues: Oxygen
Figure 18-3a: Gas exchange at the alveoli and cells
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Gas Exchange in the Lungs and Tissues: Carbon Dioxide
• Diffusion out of cells (down diffusion gradient)
• Into blood• Buffer role• Conversions:
• Plasma• Bicarbonate
• On Hb• Into alveolus & expiration
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Gas Exchange in the Lungs and Tissues: Carbon Dioxide
Figure 18-3b: Gas exchange at the alveoli and cells
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Alveolar Exchange and Diseases Related to Exchange
• Wet surface• Thin epithelia• Little ECF • Diseases:
• Emphysema• Fibrotic Lung• Pulmonary edema• Asthma
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Alveolar Exchange and Diseases Related to Exchange
Figure 18-5: Oxygen diffuses across the alveolar and endothelial cells to enter the plasma
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Overview of Hemostasis: Clot Formation & Vessel Repair
Figure 18-4: Pulmonary pathologies that affect alveolarventilation and gas exchange
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Gas Transport in the Blood: Oxygen
Figure 18-6: Summary of oxygen transport in the blood
• 2% in plasma• 98% in
hemoglobin (Hb)
• Blood holds O2 reserve
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Gas Transport in the Blood: Oxygen
Figure 18-7 : The role of hemoglobin in oxygen transport
PLAY Animation: Respiratory System: Gas Transport
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Hemoglobin Transport of Oxygen: Disassociation Curve
• 4 binding sites per Hb molecule• 98% saturated in alveolar arteries• Resting cell PO2 = 40 mmHg• Working cell PO2 = 20 mmHg• More unloaded with more need• 75% in reserve at normal activity
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Hemoglobin Transport of Oxygen: Disassociation Curve
Figure 18-8: Oxygen-hemoglobin dissociation curve