Appetite is the desire to eat food. It serves to take the energy from food to maintain metabolic needs. The drive reduction theory is an opposing tendency. The theory says that people have psychological need that creates a drive that motivates a person to satisfy their need. Our drive reduces when we eat and satisfy our hunger.
The autonomic nervous system regulates the functions of our internal organs, such as the heart, stomach and intestines. The ANS contains, the sympathetic nervous system and the parasympathetic nervous system. They are opposing tendencies. The parasympathetic nervous system calms the body down after the sympathetic nervous system causes the body to go into fight or flight.
Color Vision shows opposing tendency through the opponent process theory. The opponent process theory notes that there are some color combinations that we never see, such as reddish-green or yellowish-blue. Opponent-process theory says that color perception is controlled by the activity of two opponent systems, a blue-yellow mechanism and a red-green mechanism.
The body becomes dependent on drug use. Drug tolerance occurs when a person’s reaction to a drug decreases so they need larger and larger doses to have the same effect. Drug withdrawal occurs when people try to quit the drug. When withdrawal occurs the body wants the drug, but the person can’t get the drug so the body reacts by getting dizzy and nauseas etc. People get addicted to drugs because the drug gives the body