The digestive system comprises the organs that break down and digest food, and remove unabsorbed waste from the body. It includes the mouth, esophagus, stomach, small intestine, large intestine, liver, gallbladder and pancreas. Food is broken down mechanically and chemically by these organs through processes like chewing, peristalsis, enzymatic digestion, and absorption of nutrients into the bloodstream. Wastes are eliminated through the large intestine and anus.
2. Introduction
• This comprises organs that break down and
digest food, and remove unabsorbed wastes
from the body. Its main feature is the
alimentary canal (gut) measuring about 30
feet (9m) in length.
3. Anatomical Structure Overview 1
• Mouth cavity: Teeth, tongue, salivary glands,
and other structures begin processing food for
swallowing.
• Esophagus: Connects the throat and the
stomach. Food is moved by an action called
“peristalsis”.
• Stomach: Food is churned, disinfected, and
begins to digest.
4. Anatomical Structure Overview 2
• Sphincters: Rings of muscle that close at the
junction of the stomach, the duodenum, and the
anus.
• Digestive juices: Saliva, gastric, sm. Intestine,
and pancreatic juices contain enzymes for
digesting specific food substances.
• Small intestine: Approx 21 ft (6.5m) in length,
and connects the stomach and lg. intestine.
Subdivisions (beginning from the stomach) are
the duodenum, the jejunum, and ileum. Most
digestion occurs here.
5. Anatomical Structure Overview 3
• Large intestine: Approximately 5 ft (1.5m) in
length, and runs from the ileum to the
rectum. Main sections are the cecum, the
ascending, transverse, and descending colon,
and the sigmoid flexure.
• Appendix: A narrow tube projecting from the
cecum.
• Rectum: Extends from the sigmoid flexure
and ends at the anus.
6. Anatomical Structure Overview 4
• Liver: This large organ in the upper part of the
abdomen secretes bile and stores vitamins.
• Gall bladder: This sac, located behind the
liver, stores bile to be released into the
duodenum.
• Pancreas: A large gland that secretes insulin
and pancreatic juice into the duodenum.
12. DIGESTIVE JUICES
1. Mouth: Chewing helps to break down food
2. Stomach: Enzymes in gastric juice further
break food down
3. Sm. Intestine: Enzymes in pancreatic and
intestinal juices convert proteins into amino
acids
4. Absorption through intestinal lining into
the portal (liver) system
5. Portal vein
6. Liver: Amino acids made into useful
proteins, stored as fat, or excreted as urine