-
Only mechanism for gas echange
Diffusion
-
When gas is being exchange between two media (water and air) equilib will be reached when
Gas molecules enter & leave at same rate
-
With fick's law, high diffusion rates require
Large A and short L
-
In ficks law, q must be
Slow enough to allow contact between blood & medium
-
In ficks law, variables should be
Adjustable so gas exchange meets needs of animal
-
Respiratory structures in ANY taxon will have
Large surface area and short diffusion distances
-
Gas exchange must be kept
Moist
-
In respiration, metabolic costs mean
Larger respiratory surfaces in endotherms vs ectotherms.
-
To maximize partial pressure gradients,
Minimize path length, ventilation, and perfusion
-
Actively more external medium over gas exchange
Ventilation
-
Actively moving internal medium to transport co2 to membrand and o2 away
Perfusion
-
Total _______ in gills is much greater than the body itself
Surface area
-
Cray fish and lobster move water _____ gils with ______.
Over; appendages
-
Muscles and clams move water with ______.
Cilia
-
Fish move water ____ gills as they swim
Over
-
Gill filaments are covered with
Gill lamellae; lots of surface area for gas exchange
-
Countercurrent exchange, blood and water __________
Flow in opposite directions
-
In countercurrent exchange, pressure gradient at both ends
Extracts the maximum amount of oxygen from the water via diffusion
-
Small insects depend on ____ for ventilation
Diffusion
-
Larger insects use flight muscles to
Push air through system
-
In insects there is no _______ necessary
Circulatory system participation
-
Normal amount of air inspired and expired during quiet breathing
Tidal volume
-
Stale air that remains after exhalation
Residual volume
-
In birds, site of gas exange are
Parabronchi
-
These have air capillaries surrounded by blood capillaries
Parabronchi
-
Air pathway
Nasal cavity, pharynx, larynx, trachea, two bronchi, smaller bronchioles
-
Reuces surface tension in aveoli, decreases effort necessary for inflation
Sufractant
-
Affects premature infants may not produce enough; they develop
Respiratory distress syndrome
-
Collapsed lung
Atelectasis
-
Loss or damage to alveoli, increase in residual hormone
Emphysema
-
4th leading cause of death
Emphysema
-
Breathing control centers are in
Medulla oblongata and pons
-
Neurons in pons
Regulate tempo
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