3. ∗ Series of hollow organs joined in a long twisting tube
from the mouth to the anus. Other organs are
involved that help the body break down and absorb
food.
∗ Made up of: mouth, esophagus, stomach, small
intestine, large intestine(also called the colon)
rectum, and anus.
Made up of the digestive tract
4. • Begins in the mouth where food enters and is partially
broken down by chewing and by the salivary
enzymes.
• After chewed and swallowed, the food enters the
esophagus. The esophagus is a long tube that runs
from the mouth to the stomach. In order for the food
to get from the mouth to the stomach, the esophagus
uses rhythmic, wave-like muscle movements (called
peristalsis).
Process
5. ∗ Once it reaches the stomach, the food is churned and
bathed in gastric acid. Food in the stomach that is
partly digested and mixed with stomach acids is called
chyme.
∗ When the food is finished breaking down in the
stomach, it then enters the duodenum, which is the
first part of the small intestine.
6. ∗ It then enters the jejunum and then the ileum (the
final part of the small intestine). In the small intestine,
bile (produced in the liver and stored in the gall
bladder), pancreatic enzymes, and other digestive
enzymes produced by the inner wall of the small
intestine help in the breakdown of food.
7. ∗ Food then passes into the large intestine.
∗ Some of the water and electrolytes (chemicals like sodium) are
removed from the food there.
∗ Bacteria like Bacteroides, Lactobacillus acidophilus, Escherichia
coli, and Klebsiella in the large intestine help in the digestion
process.
∗ The first part of the large intestine is called the cecum, which the
appendix is connected to.
∗ Food then travels upward in the ascending colon. The food
travels across the abdomen in the transverse colon, goes back
down the other side of the body in the descending colon, and
then through the sigmoid colon.
8. ∗ Finally, solid waste is then stored in the rectum until it
is excreted via the anus.
9. ∗ Crohn’s Disease: It is a type of inflammatory bowel disease that
can affect any part of the gastrointestinal tract from the mouth
to the anus. It has a wide variety of symptoms, including:
abdominal pain, diarrhea, or weight loss. Also outside the
gastrointestinal tract it can cause skin rashes, arthritis,
inflammation of the eye, tiredness, and lack of concentration.
∗ Caused by interactions between environmental, immunological
and bacterial factors in genetically susceptible individuals.
∗ Results in a chronic inflammatory disorder, where the body's
immune system attacks the gastrointestinal tract possibly
directed at microbial antigens.
Diseases in the Digestive System
10. ∗ Gastroesophageal reflux disease (GERD): Chronic
symptom of mucosal damage caused by stomach acid
coming up from the stomach into the esophagus.
∗ Caused by changes in the barrier between the
stomach and the esophagus, which normally holds
the top of the stomach closed. It can also be caused
by an impaired expulsion of gastric reflux from the
esophagus, or a hiatal hernia. These changes can
either be temporary or permanent.
