Post on 18-Dec-2015
Gas Exchange
I. Introduction
A. Why?
B. Forces & Factors
Forces to drive gas exchange?
Figure 42.23
Factors help to maximize exchange?
Surface area
Moisture
C. Transport
II. StrategiesA.
Direct
Direct method = Poriferans, Cnidarians, and Platyhelminthes
Figure 42.21Figure
33.4What would be required to lead this life style?
Constant water movementSimple thin structure
B. Gills1.
Structure
Figure 42.21Figure
33.3
Gills == Mollusca to Vertebrata
Figure 42.22
Figure 42.21Figure
33.3
Fish Gills
2. Forces
Figure 42.21Figure
33.3Ram ventilation vs.
Advantages vs. Disadvantages
Gulping
Figure 42.21Figure
33.3
Circulation of water coupled with perfusion of blood
Figure 42.23
Figure 42.21Figure
33.3
swim bladder in bony fishes via the gas gland
Figure 34.16
C. Tracheal Systems1.
Insecta
Figure 42.21Figure
33.3
direct oxygen delivery system to the muscle fibers
Figure 42.24
2.
Chordata
a. Amphibians
Figure 42.21Figure
33.3
Circulate air to lungs from mouth and skin ==PP breathers
b. Reptilians
Figure 42.21Figure
33.3
PP breathers
c. Avians
Figure 42.21Figure
33.3
Negative pressure breathers move air into their lungs and air sacs
Figure 42.21Figure
33.3
Negative pressure breathers move air into their lungs and air sacs
Figure 42.27
d. Mammalians
i. Air tubes
Figure 42.21Figure
33.3
Negative breathers use muscle contractions to move air
pseudostratified ciliated columnar with goblet cells
Figure 42.25
ii. Lungs
Figure 42.21Figure
33.3
alveoli for gas exchange
Type I and Type II cells
Figure 42.25
Figure 42.21Figure
33.3
alveoli for gas exchange
Figure 42.21Figure
33.3
Lung expansion == muscle contraction
Figure 42.28Quiet versus Forced Inhalation vs.
Exhalation
iii. Control
Figure 42.21Figure
33.3
Pons, Medulla Oblongata, and the Hypothalamus
Figure 42.29
iv. Transport
Figure 42.21Figure
33.3
partial gas pressures
Figure 42.30
Figure 42.31a & b
Figure 42.21Figure
33.3
Respiratory pigments transport oxygen and also bufferCO2 is transported via other mechanisms
Figure 42.28
Dissolved in plasma about 7%Bound to globin about 23%Travels bicarbonate shuttle about 70%
Figure 42.21Figure
33.3
Figure 42.28
Figure 42.32
Quantity doesn’t mean Quality.