digestive, circulatory, excretory, endocrine and reproductive systems.
The Digestive System
The digestive system breaks food down into simpler chemical compounds that can be eas-
ily absorbed by cells or, if not absorbed, eliminated from the body in waste products.
digestive process begins as soon as food is ingested, when enzymes (EN-zimz) secreted by the sali-
vary (SAL-i-ver-e) glands (1) start breaking down the food. Food travels down the pharynx (FAR-
ingks) (2) and through the esophagus (e-SOF-
ah-gus) (3) into the stomach (4), propelled by
a twisting and turning motion of the esophagus
called peristalsis (per-i-STAL-sis). In the
stomach, hydrochloric (hi-dro-KLO-rik) acids
and several other enzymes further break down
food. One of these other enzymes called pepsin
is responsible for the breakdown of protein into
polypeptide (pol-e-PEP-tide) molecules and
free amino acids, which are of particular impor-
tance to the production of hair, skin and nails.
As partially digested food passes from the
stomach into the small intestine (5), the
assimilation of nutrients begins. Nutrients
are absorbed by the villi (VIL-i), which are
finger-like projections of the intestine walls,
and transported through the circulatory sys-
tem to the tissues and cells of the body.
Undigested food passes into the large intestine
(6), or colon, which stores the waste for even-
tual elimination through the anal canal. This
entire process of digestion takes about 9 hours
As a reminder, the digestive system, also known as the gastrointestinal system includes,
1. Salivary Glands
5. Small Intestine
6. Large Intestine
Perhaps you have heard it said, "The way to a man's heart is through his stomach!" Well, the truth
happiness and relaxation promote good digestion
. Good digestion helps keep all other
bodily functions on track.