duct. The hepatic duct then empties into the duodenum (the first portion of
the small intestine).
Bile is used as an alkalizer, anti-inflammatory, and emulsifier of fats. It
works with pancreatic lipase to break down large fat molecules. Bile contains
bilirubin, biliverdin, cholesterol, organic and inorganic substances and salts,
lecithin, mucin, etc.
Cholecystokinin (pancreozymin) is a hormone from the intestinal wall (of
the duodenum) that causes the gallbladder to contract, releasing bile.
Cholecystokinin (pancreozymin) is triggered by fats entering the small bowel.
In Summary
The tissues of the alimentary canal, which is called the digestive tract, are
formed from several layers of cells. The first layer is called the mucous
membrane; it lines all passages and cavities of the body that have contact with
oxygen. This mucous membrane consists of epithelial cells, also referred to as
the mucosa, which secretes moisture or mucus to aid in the protection and
function of the respective organ. We also have the sub-mucosa or basement
membrane. Then the connective and the smooth muscle tissues. Most of the
mucus of the mucosa comes from the Brunner’s glands, which are located in
the sub-mucosa.
We consume food and drink for the very purpose of obtaining fuels, as
well as for building and repairing materials. Basically, most elements and
compounds are used as energy sources for the body. All foods and drinks
must first be broken down from their gross unusable forms into their simplest
or nutritional substances so the body can absorb them and use them. Cell
membrane walls have microscopic pores so that only the simplest of elements
can enter. If not, large particles may enter and cause cellular damage.
Physically, however, most by-products of digestion, if properly broken
down into their simplest form, can now be absorbed through the villi into the
capillary (blood) bed. The blood now acts as a transporter, carrying the
nutrients, building blocks and fuels to the liver, then to the heart, and finally
releasing them into the general system for its needs. By-products of digestion
include amino acids, monosaccharides (simple sugars), fatty acids, glycerol,
vitamins and minerals, etc.