1.1. The task describes the effect of negative feedback, since it implements a strategy for stabilizing the physiological process.
1.2. The 3rd equation is correct, since in the physiological system, in addition to the properties of the elements, new properties appear due to interaction of the elements of the system.
1.3. These are different levels of system organization. The functional system is located between the level of physiological systems and the level of the whole organism. The elements of the physiological system are organs, the elements of the functional system are physiological systems. The main difference is that in the functional system the final effect is a useful result, and not an action in itself.
1.4. During the first stage, a prediction reaction is involved, which makes it possible to make preliminarily adaptations in preparation for a physical activity even before it begins (pre-launch conditioned reflex). During the second stage, disturbance regulation takes place, and the centers of respiration and blood circulation are stimulated from the proprioceptors of the musculoskeletal system and the motor cortex of the brain, even before a change in homeostasis. During the third stage, deviation is regulated through negative feedback, the purpose of which is to restore the changed parameters of homeostasis - pH, pCO2 pO2.
1.5. Ivan Mikhailovich Sechenov.
2.1. With a decrease in the level of ATP in the neurons, the intracellular concentration of Na+ will increase as a result of energy insecurity in the Na+/K+ pump. Therefore, K+ channels, dependent on ATP and Na+ ions will be activated, which increases the diffusion of K+ out of the cell and prevents the development of depolarization.