Fire algae are known as dinoflagellates because they have two flagella.
A flagellum (pl. flagella) is a whip-like structure that allows a cell to move.
Absorption takes place in the small intestine. Fatty acids and glycerol are formed by digestion of lipids which diffuse through the one-cell thick cell wall of villi and into lacteals (lymphatic vessels).
<span>The submucosa<span> of the alimentary or the gastrointestinal tract contains numerous glands (i.e. gastric glands in the stomach, Brunner's glands in the duodenum) as well as numerous blood vessels. The submucosa also contains the submucosal nerve plexus or Meissner's plexus which functions to control the secretion of the submucosal glands.
</span><span><em>Another layer that has a nerve plexus is the muscularis layer which has the muscular nerve plexus or Auerbach's plexus which control the contractions of the gastrointestinal tract. The Meissner's and Auerbach's plexus are collective called the enteric nervous system.</em></span></span>
