Concept List: Evolution of the Lung

Question 1

Distinguish between the different types of organs used for respiration

Answer 1

Gills: most efficient, water
Faveolar: next efficient, air, cross-current, in one side out the other
Alveolar: least efficient, air, random current, one exit/entrance

Question 2

Describe the changes to the respiratory surfaces as vertebrates evolved

Answer 2

Increased

Question 3

Describe the evolutionary changes in the anatomy that allowed a switch from a positive
to a negative pressure system

Answer 3

Loss of ribs, diaphragm.

Question 4

Describe the similarities and differences between the alveolar and faveolar lungs

Answer 4

Similar: can have sacs, move air
Different: exchange system, one exit/entrance vs. separate, efficiency

Question 5

Describe the differences in air flow and efficiency between the avian and mammalian lung

Answer 5

Avian: unidirectional, cross-current, more efficient, high-altitude, evolved earlier

Mammalian: back and forth, less efficient, evolved later

Question 6

Describe the advantages and disadvantages to positive and negative pressure systems

Answer 6

PP: Movement can hinder respiration

NP: Allows eating and respiration at once, movement helps respiration

Question 7

Distinguish the differences between positive pressure and negative pressure systems and
give examples