Question

Advantages and disadvantages of aquatic medium in respiration

Answer 1

The insect respiratory system is made up of air tubes that branch throughout the body. The largest tubes, called tracheae, open to the outside. The finest branches extend close to the surface of nearly every cell, where gas is exchanged by diffusion across the moist epithelium that lines the tips of the tracheal branches. Because the tracheal system brins air within a very short distance of virtually every body cell in an insect, it can transport O2 and CO2 without the participation of the animal's open circulatory system.

For smaller insects, diffusion through the tracheae brings in enough O2 and removes enough CO2 to support cellular respiration.

Larger insects meet their higher energy demands by ventilating their tracheal systems with rhythmic body movements that compress and expand the air tubes like bellows.