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Topic: Human Digestive System
 The human digestive
system is a system of
organs and glands which
digest and absorb food and
its nutrients.
 There are two types of
breakdown of food:
mechanical and chemical.
 Human digestive systems
start at the mouth and
ends at the anus
 About 9 meters in total
length
 Have mechanical and chemical processes
 Mechanical: food is broken down from larger pieces into
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smaller pieces, known as mastication or chewing
Chemical: uses saliva which contains a digestive enzyme,
salivary amylase
Salivary amylase breaks down starches (monosaccharide)
into maltose (disaccharide)
The food is then swallowed and travels down into the
esophagus then into the stomach via a process called
peristalsis
Peristalsis= wave like movements which propel food down
into our stomach
 Is a large organ which can be referenced as being a J-shaped
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pouch
Churns food and contains a strong acid (gastric acid) which
breaks down food so it can be fully digested and absorbed
by the small intestine
Contains 2 types of cells
Parietal Cells= secrete gastric acid
Chief Cells= release pepsinogen and gastric lipase
These two cells work in conjunction with eachother to
convert pepsinogen into pepsin
This food is now known as chyme due it becoming partly
digested and mixing with gastric acid
 Food from the stomach enters the duodenum
 Duodenum= 1st section of the small intestine
 This chyme is then mixed with 3 liquids
 1. Bile (made in liver)= emulsify fats and neutralizes
chyme
 2.Pancreatic juices which are made from the pancreas
 3. Intestinal enzymes (sugars, trypsin, chymotrypsin)
 This chyme goes from the duodenum to the jejenum
and to the ileum, all of which are part of the small
intestine
 Food will enter the cecum of the large intestine from the
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ileum of the small intestine
Waters and salts (electrolytes) are removed from the food
and absorbed into the body
3 parts: Cecum, Colon, and Rectum
The food that was not digested or absorbed will be mixed
with other waste products from the body and form feces
Feces are stored in the rectum until they can be eliminated
from the body
Elimination occurs in the anus and is regulated by the anal
sphincter muscle
Food Travel
(Start) Mouth
Esophagus
Stomach
Small Intestine
Large Intestine
Anus (End)