The term mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes. In chemical digestion, enzymes break down food into the small molecules the body can use.igestion begins in the mouth with the secretion of saliva and its digestive enzymes. Food is formed into a bolus by the mechanical mastication and swallowed into the esophagus from where it enters the stomach through the action of peristalsis.
The stigma is generally in the center of the flower and stands up on the style, taller than the surrounding anthers. It usually has a gelatinous or visceral appearance, which is slightly damp and furry.
Stigma (botany) - Description. 1  The stigma, together with the style and ovary comprises the pistil, which in turn is part of the gynoecium or female reproductive organ of a plant. 2  The stigma receives pollen and it is on the stigma that the pollen grain germinates. 3  Pollen is typically highly desiccated when it leaves an anther.