Summary:The Digestive system involves most of the organs in our mid section of our bodies. To begin with the food enters our mouths and is chewed up. Then this food is swallowed and travels down our esophagus to the region of our stomachs. The food is now somewhat broken down by the chemicals and acids that are in our bellies and is pushed into the small intestine.In the gastrointestinal tract food is hydrolyzed into monomers. Then the food enters the large intestine once the small intestine is done with it. After the long journey the food is so broken down that is turned into a paste like substance called fecal material and travels to the ascending colon, transverse colon, descending colon and finally to the sigmoid colon where it reaches the rectum and is pushed out of the anal canal.

Digestive system basics

Ingestion: Eating the food
Mastication: Grinding the food and mixing it with saliva
Degluttition: Swallowing the food
Peristalsis: Wave like movements that is moving the food through the gastrointestinal tract
Digestion: The break down of food by means of endocrine and exocrine secretions
Elimination: Removal of excess waste

How does this apply to my career?
Since The digestive system is one of the systems most people have problems with when getting older. This system is very important to get a good grasp on since the baby boomers of the the 50s and 60's are beginning to have problem with their health. As a nurse I have to understand what might be going on with a patients that are having trouble having a bowl movement or dealing with stomach pains. I need to know just what medications to give and along with what they do and how they work before I can administer them to the patient. Its also important to know all the parts of the digestive system because It would give me more understanding when someone is having trouble swallowing, have acid reflux disease, or sometime the blood in a patients bowl movement. Its important to know what is normal and abnormal to give the right care.Disorders of the digestive system.

Small intestine-
The small intestine is part of the GI tract and is lined made up of mucosa with simple columnar epithelium , submucosa,smooth muscle and serosa. The small intestine can reach up to 20 ft in length and is comprised of three main parts named the duodenum,jejunum and the ileum.since the small intestine is made up of muscle and villi the food is pushed through and absorption occurs in this organ.
The Function:

Large intestine-The Large intestine is made up of mucosa and a number of goblet cells and a longitudinal muscle layer. This runs the entire length of the colon. The intestine is 2.5 cm wide and 1.5 m long and It begins at the ileocecal valve of the small intestine and extends to the rectum. The large intestine is divided into 7 main parts listed below. These parts help the absorption of water, absorb certain nutrients,store fecal material, and maintain fluid balance in the body.
  • Caecum
  • Ascending colon
  • Transverse colon
  • Descending colon
  • Sigmoid colon
  • Rectum
  • Anal canal

    • Little or no digestive function
    • Absorbs water
    • Absorbs electrolytes
    • Absorbs B and K vitamins
    • Stores bacteria that break down food
    • Store waste

The three molecules, carbohydrates, proteins, and lipids are important molecules in food that need to be physically and chemically digested by the digestive system. for each nutrient:

Where this is digested
The enzymes that break it down.
How the nutrient is absorbed.
How the body uses this nutrient.
Mouth & Duodenum
Salivary Amylase &
Pancreatic Amylase

The broken down monosaccharides move across the epithelial membrane by secondary active transport and then is secreted into blood capillaries.
Small Intestine
Pancreatic lipase
They leave the micelles and pass through the membrane of the micro villi and enter the intestinal epithelial cells.
Metabolism, hormones, immune system, proper body function
Stomach & Small Intestine
Pepsin, trypsin, chymotrypsin, carboxypeptidase & aminopeptidase
The free amino acids are absorbed by co-transport with sodium into the epithelial cells and into the blood capillaries.
Energy production and the make up of other cells.
fig2_xlf.jpgLipidsfig1_xl.jpg Protein4_b.jpg Carbs

Fun Fact: In your life time your digestive system can handle about 50 tons of food and water!

Thanks to:
Human physiology 11th edition -McGraw-Hill
Anatomy and Physiology 4th edition-Mcgraw-Hill