Which statement is the best definition of external respiration?
A. The bulk flow of air or water to and from the gas-exchange membrane
B. The thin layer of tissue, typically consisting of one or two epithelia, that separates the internal tissues of the an
c. The process by which O2 is transported from the environment to the gas-exchange membrane and CO2 is transported from the membrane to the environment
A blood sample that has an extremely low partial pressure of CO2 is most likely from a(n)
animal exchanging respiratory gas with water.
The bellows action used by birds in breathing is generated by
expansion and compression of the air sacs.
Carbon dioxide excretion in the bullfrog is highest across the
skin at all stages.
The substance responsible for the prevention of alveolar collapse is
surfactant.
In mammals, ventilation is modulated by chemosensation of
CO2, H+, and O2.
Which animal uses a tracheal system?
Flea
In mammals, moving air into the lungs is achieved mainly by
contracting the diaphragm.
In insects, oxygen moves through the tracheal system by
diffusion, convection, and rhythmic tracheal compression.
Which statement regarding mammalian ventilation is false?
A. There is no convective movement of gas in the alveoli.
B. Gas exchange occurs in the respiratory bronchioles.
C. Inspiration always requires muscle contraction.
D. Expiration always requires mus
c. Expiration always requires muscle contraction.
The major stimulus for increased ventilation in fish is
both decreased O2 and increased exercise.
Which morphology allows for the most efficient gas exchange?
Countercurrent
The partial pressure of O2 in the blood leaving the breathing organ depends on the
flow of air or water at the interface.
Which animals use positive pressure ventilation?
Amphibians
The protective external flap that covers the gills on a fish's head is called the
operculum.
Which animal group tends to have the thinnest gas-exchange membrane?
Birds
The gas-exchange system in birds is
cross-current.
The maximal possible tidal volume is called the
vital capacity.
Within the molluscs, a lung modified from the mantle cavity to allow respiration of air on land is seen in which group?
Snails
The entrance to the insect tracheal system is via
spiracles.