lesson 13 gas exchange 1 aim: how have mechanisms for gas exchange evolved? do now: go over pp....
TRANSCRIPT
Lesson 13 Gas Exchange 1
AIM: How have mechanisms for gas exchange evolved?
DO NOW: Go over pp. 247-248
HW: Read Ch. 34 pp. 698 – 702
STUDY
Basic Vocab
• Respiration vs. gas exchange
• Respiratory surface
• Respiratory medium (air vs. water)
• Ventilation
• Countercurrent mechanism
• Positive vs negative pressure breathing
• Form fits function (alveolus)
• Simple diffusion
Terrestrial Organisms
• Problem of desiccation
• Need respiratory organs w/i the organism’s body
• Evolution of lungs from swim bladder of fish
Adaptations for Gas ExchangeMonera, Protista,
Porifera,
Cnidaria
Platyhel-minthes
Anneli-da
(Earth-worms)
Arthropoda (grasshop-per)
Fish Amphibia Mammalia & Aves
Negative Pressure Breathing• deep breath contraction of rib muscles
volume of rib cage P in lungs air rushing from area of high P (outside body) to the area of lower P (inside lungs).
Gas exchange in humans:
• Nose pharynx larynx trachea bronchi bronchioles alveoli
V of lungs P air rushing in by bulk flow
• Negative pressure breathing