Approximately 4 grams of glucose, a simple sugar, is present in the blood of a 70 kg (154 lb) human at all times.
In the digestive system the stomach is involved in the second phase of digestion, following chewing.
There are a number of medical conditions associated with defecation, such as diarrhea and constipation, some of which can be serious.
Hunger and satiety are sensations. Hunger motivates the consumption of food. Satiety is the opposite of hunger; it is the sensation of feeling full.