During periods of high metabolic activity in insects, fluid at the ends of the tracheoles is withdrawn into the surrounding muscle tissues.
Which of the following correctly describes the cause of this fluid movement and its primary physiological advantage?
Active transport of sodium ions out of the muscle cells lowers the tracheolar water potential, pulling water out of the tracheoles; this increases the partial pressure of oxygen in the gas phase.
Anaerobic respiration in muscle cells produces lactate, lowering their water potential so water moves into the cells by osmosis; this decreases the diffusion distance of oxygen through liquid.
Aerobic respiration increases carbon dioxide concentration in the tracheoles, raising their hydrostatic pressure and forcing water into the muscle cells; this maintains a constant ventilation rate.
Anaerobic respiration in muscle cells produces lactate, raising their water potential so water moves into the tracheoles by osmosis; this increases the surface area for gas exchange.