This edition: Respiration
Most animals exchange gas with their environment, taking in oxygen and giving off carbon dioxide. Respiratory adaptation depends on the evolution of the animal with respect to its size, need for energy, and environment. Dr. Karen Martin gives an overview of aerobic respiration, and graphic animation shows the diffusion of gases across a moist membrane with changing concentrations. A tour of the human respiratory system highlights the middle segment of the program. Dr. Christopher Cooper discusses the process of breathing. The viewer actually follows one breath of air on inhale down the throat into the trachea and through the bronchial tree. The program branches off into the circulatory system as Dr. Gerald Kooyman explains how the physiology of seals and penguins in the Antarctica stores air for long periods as these animals dive for food.