Chap 46 Gas Exchange-SM17 PDF

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Summary

Lab notes for BIOL-K 103 lab by Dr. Robert Yost. IUPUI. What to know for quizzes over these specific labs....

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Chapter 46: Gas Exchange Learning objectives After reading the associated assignment in the textbook, attending lecture, and/ or attending the accompanying laboratory and recitation, you should be able to: 1.

Compare and contrast gas exchange in air and water (knowledge/comprehension/analysis)

2.

Compare and contrast negative and positive ventilation including animal examples (knowledge/comprehension/analysis)

3.

Compare and contrast gas exchange surfaces and structures including how they work and animal examples (knowledge/comprehension/analysis)

4.

Describe the structure of the human respiratory system, the conducting and respiratory zones, the structure in the pleural cavity, the structure of an alveolus, the structure of the respiratory membrane, the mechanics and pressures associated with ventilation, and the properties of the lungs including an understanding of what happens to ventilation when a pressure of property is changed (knowledge/comprehension/analysis)

5.

Name and define the lung capacities and volumes (knowledge/comprehension)

6.

Name and define two laws associated with partial pressure and diffusion (knowledge/comprehension)

7.

Name the common respiratory pigments and define how blood oxygen measurements are made (knowledge/comprehension)

8.

Name, compare and contrast factors affecting hemoglobin saturation with oxygen including graphs for the Bohr and Haldane effects, temperature and pH (knowledge/comprehension/analysis/synthesis)

9.

Summarize the mechanisms by carbon dioxide is transported in the blood, including labeled graphs and figures in the response (knowledge/comprehension/analysis/synthesis)

10. Describe the effect of neuronal and chemical control on ventilation (knowledge/comprehension) 11. Describe how peripheral chemoreceptors respond to oxygen levels and the effects of hyper and hypoventilation (knowledge/comprehension) 12. Describe the oxygen level positive feedback mechanism involved in ventilation (knowledge/comprehension)

Some New Words

the shift in the hemoglobin-oxygen saturation curve that occurs as a result of changes in carbon dioxide levels Chloride shift movement of chlorine ions into or out of the red blood cell in the opposite direction of the movement of bicarbonate ion Compliance yielding to pressure without changing structure or function Concurrent two media flowing in the same direction Countercurrent two media flowing in opposite directions Haldane effect the shift in the hemoglobin-oxygen saturation curve that occurs as a result of pH changes Hypoxia low levels of oxygen in the tissues and or blood Negative ventilation using negative pressure to draw air or water over a respiratory surface Pleural cavity fluid filled cavity in which the lungs are housed in the thorax Positive ventilation forcing of air or water over a respiratory surface Spiracle an external opening into the tracheal system of insects Bohr effect

Gas Exchange Chapter 46 Respiratory medium comparison: Air vs. Water Air Advantages 1. O2 concentration: higher 2. O2 diffuses faster 3. requires less energy Disadvantage: 1. surfaces must be kept moist

Water Advantage: 1. no desiccation Disadvantages 1. Water and ion movement: fluid tonicity; animal hypertonic in freshwater; hypo in marine 2. Gas solubility: co2 more than o2 3. Gas concentration: o2 less than in air

Ventilation can use positive or negative pressure Positive pressure ventilation A. Process ______________________________________________________________________________ B. Examples ______________________________________________________________________________ Negative pressure ventilation A. Process ______________________________________________________________________________ B. Examples ______________________________________________________________________________

Respiratory Surfaces and Structures Requirements of respiratory surfaces moist surface (all) adequate blood supply (most) ventilation (most)

Respiration across body surfaces Where:  Own body surface  Tracheal tubes: air (no blood vessels)  Gills: water  Lungs: air Examples E.g. nudibranch mollusks, most annelids, and amphibians

Respiration in tracheal system Structure: order 1, 2, 3 1. Spiracle: tiny opening where air enters tracheal tubes 2. Tracheal tube: delivers air directly to cells 3. Tracheole tubes Ventilation Muscle contraction Body movements Mini explosions Examples Insects and some other arthropods

Ventilation pressure Positive pressure Ram ventilation Negative pressure

Gills as a respiratory surface

Epithelium  ciliated Fluid exposure _____________________________________________________________________________ Types of Gills External __________________________________________________________________ Internal ___________________________________________________________________ Dermal ___________________________________________________________________

Gas exchange in gills of bony fish Counter-current exchange Counter-current exchange in fish gills Gill filaments  provide extensive surface for gas exchange Fluid flow  opposite Effect  maximizes the difference in [O2] between blood-water Result ©Pearson Education

©Pearson Education

Lungs as a respiratory surface Development:  Change in surface area

Ventilation and gas exchange in bird lungs Structure Air sacs: extensions that draw air into the system Parabronchi:  end of narrowest branches of airway  air continuously flows through them  Air flow is unidirectional First inhalation: air flows into lungs Second inhalation: air leaves the body as a breath enters

http://images.slideplayer.com/1/259711/slides/slide_33.jpg

Gas exchange in parabronchi of birds Crosscurrent exchange Blood flow and air flow b. Efficiency

©Pearson Education

Human Respiratory System

Hill pg 545

General structure

Airway zones Conducting zone Trachea: Bronchi Bronchioles Terminal bronchioles Respiratory zone Respiratory bronchioles Alveoli

Lung Location and Associated Membranes

Thoracic cavity: chest Visceral pleural membrane: on the organ Pleural cavity: between pleural membranes Parietal pleural membrane

Individual alveolus Tissue Cells Type I Type II Macrophage

Ventilation Human Lungs

Ventilation Pressures Atmospheric __________________________________________________________________________ Intrapleural __________________________________________________________________________ Transpulmonary __________________________________________________________________________ Intraalveolar __________________________________________________________________________

Rhoades and Pflanzer 4th ed

Mechanics of ventilation

Lung properties Elasticity ______________________________________________________________________________ Extensibility ______________________________________________________________________________ Compliance ______________________________________________________________________________ Contributions of surfactant ______________________________________________________________________________

Rhoades and Pflanzer 4th ed

No slide Objective 5: Name and define the lung capacities and volumes (knowledge/comprehension)

Tidal volume

Amount of air moved into and out of lungs with a normal resting breath Expiratory reserve volume Expiratory volume beyond tidal volume Inspiratory reserve volume Inspiratory volume beyond tidal volume Residual volume Volume of air remaining in lungs at end of a maximal expiration Vital capacity Maximum amount of air a person can exhale after filling lungs to the maximum

Gas Exchange in Alveoli (Gas Laws) Dalton’s law of partial pressures  Total pressure of mix is sum of pressures of individual gases Fick’s law of diffusion  Amount of O2 of CO2 that diffuses across the membrane of an alveolus depends on differences in partial pressure on the two sides of the membrane and on the surface area of the membrane

Respiratory pigments: Oxygen transport Function: increase quantity of O2 that blood can transport Hemoglobin [contains iron]: vertebrates; red Hemocyanin [contains copper]: mollusks and arthropods; blue Myoglobin: animals

Oxygen measurement O2 carrying capacity: max amount of O2 that hemoglobin can transport O2 content: amount of O2 bound to hemoglobin Percent O2 saturation: ratio of O2 content to O2 carrying capacity Oxygen-Hemoglobin saturation curves Normal curve: as [O] increases, the % of hemogl0bin combined with O2 increases

Bohr Effect (pH): displacement of O2-hemoglobin dissociation curve by a change in pH

HbO2 + H+

H+Hb + O2

Haldane Effect (CO2) ____________________________________________________________________________

HbO2 + CO2

HbCOO- + H+ + O2

Temperature effect ____________________________________________________________________________

Carbon dioxide transport Dissolved in plasma: 10% Bound to hemoglobin: 30% Bicarbonate ion: 60% Carbonic anhydrase reaction

Caron dioxide transport at tissue level

Caron dioxide transport at lung level

CO2 + H2O

H2CO3

H+ + HCO3−

Neural control of ventilation (breathing)

General process ____________________________________________________________________________ Cerebral cortex ____________________________________________________________________________

Neuronal control of breathing Herring-Breuer reflex _______________________________________________________________________________ Depression of respiratory center _______________________________________________________________________________ Chemoreceptors control respiration to maintain homeostasis

Medullary chemoreceptors (CNS) Detection Response

Rhoades and Pflanzer 3rd ed

Peripheral chemoreceptors Location __________________________________________________________________________ Detect chemical changes in blood __________________________________________________________________________ Response __________________________________________________________________________

Peripheral receptor response to carbon dioxide and oxygen levels on ventilation Carbon dioxide ___________________________________________________________________________ pH ___________________________________________________________________________ Oxygen ___________________________________________________________________________

Rhoades and Pflanzer 4th ed

Peripheral chemoreceptor response to low oxygen levels Receptor stimulation by O2 When _________________________________________________________________________ Where _________________________________________________________________________ _________________________________________________________________________ Why ________________________________________________________________________

Adaptation problem ___________________________________________________________________________ ___________________________________________________________________________ = Effects of ventilation on blood gas levels Hyperventilation ___________________________________________________________________________ Hypoventilation ___________________________________________________________________________

Low oxygen levels stimulate a positive feedback mechanism ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________...