Posts tagged ‘animals’

Even primitive people knew that the food eaten by man and animals is digested in their stomachs. When skinning their game, they were sure to peep into the stomachs. Even nowadays almost no housewife can resist the tempta­tion of learning what the pike had for dinner and whether the chicken’s stomachs contain anything of interest besides small stones and sand. When hunters cut up their prey, they found in the stomachs and intestine neither meat, nor grass or seeds, but a pasty mass, as though the food had been cooked there.

It took man a long time to find out what really occurs. The food is not changed under the influence of heat: the temperature in the stomachs of even the ‘hottest’ warm­blooded animals is no higher than 38-43°C and this is not sufficient to cook food. Digestion takes place with the aid of digestive juices containing special enzymes.

The alimentary tract of man and animals is a complex chemical laboratory. The food consumed is ground, mixed with various digestive juices and moves gradually from one part to another. In each part the food is held long enough for it to be digested, being saturated with special substances. These substances are absorbed during the digestive process, that is, during the breakdown of complex chemical substances into simple ones (proteins into amino acids, fats into glycerol and fatty acids, carbohydrates into monosaccharides). What cannot be digested and used by the organism is disposed of.