A person can eat when hunger is absent because: a. the conscious mind of the cortex can override the body's signals b. the digestive tract sends messages to the hypothalamus c. the hypothalamus signals the availability of food in the environment d. the stomach intensifies its contractions and creates hunger pangs e. the glands start supplying epinephrine to the brain

a. the conscious mind of the cortex can override the body's signals

Explanation:

Physiologically the satiety center in the hypothalamus control hunger is the lateral hypothalamus,while the ventral hypothalamus ensures satiety,urge to stop eating.Therefore the sensation to eat is involuntary. Mammalian brain is made up of the higher brain centers,located in the Cerebral cortex. These are regions of the brain used for judgemental cases,and conscious reasons to meet the demand for immediate needs.

Once the urge of thirst and hunger has been met,the satiety center stimulation is stopped.However,if one wishes to eat despite the stimulation of the hunger center,The crave for this is control by the conscious cerebral cortex,which allow the person to make the decision,without the involuntary region of the brain.

Hence the need to it is no longer done for nourishment,but rather to meet up or carried out the habits of fulfilling the passion to eat.

oxygen = 21% of the atmosphere

nitrogen = 78%

carbon dioxide = 0.1%

argon =0.934%