Digestive System--

What are the 5 functions you need to consider as you watch food move through the digestive tract?

Draw a picture of the tube that is the digestive tract and label the parts.-use this picture as you answer the following questions in the sutdy guide.

What other organs and glands are associated with GI tract function?

• Which part of the GI tract are they associated with and what is their major function?

What are different ways of regulating the digetive system?

What type of cells line the GI tract? What type of muscle is found in the tube? what is covering the outside of the tube?

• What function does each of these types of cells perform?

To be absorbed by the GI tract carbohydrates must be broken down to what form?

• Proteins must be broken down to what form?
• and lipids?

What is the advantage of food particles having a large surface area?

• When during transit through the GI tract is the surface area of the food increased?
• Before you cook it or eat it which has more surface area-- a raw steak or raw hamburger?

What is saliva?

• what is its composition?
• What regulates the secretion of saliva?

What is the function of the esophagus?

• For how long is food in the esophagus?

Stomach

• What is the function of the muscular layer of the stomach?
• Why is the gastric juice so acidic?
  • what function does an acid environment perform?
  • How does the stomach protect itself from this environment?
  • What is heartburn?
• How is secretion of gastric juices regulated.
• What influences the rate of gastric emptying?
• What is in chyme?
• What is digested in the stomach?
  • What is absorbed?
• what hormones are released by the stomach?

Small Instestines

• What two glands add digestive juices to the GI tract in the duodenum?
• How is the surface area of the small intestine increased?
• What are some of the functions of the liver?
  • What is its role in digestion?
• What is the gallbladder and what stimulates it to contract?
  • What role does bile have in the digestive process?
  • what is a gallstone?
• What is the composition of the pancreatic juice?
  • What digestive enzymes does the pancreas secrete?
  • What stimualtes the release of pancreatic juices?
• What foods are digested in the small intestines?
  • What is absorbed here?
• What is peristalsis, segmentation, how are they the same, how are they different?

Large Intestines (colon)

• What is the major function of the large intestines?
  • What is digested here?
  • what is absorbed?
• What is bacterial flora and what purpose does it serve?
• what is found in feces?
• What is diarrhea?
  • constipation?
  • what causes each of these conditions?

Which parts of the GI tract are essential for life? which are less vital?

What can help to prevent colon cancer?

What is special about olestra?

About how long does food stay in ech part of the tube? What influences the transit time thru the system?

Which GI hormones are found at high levels just before you eat? soon after you eat?

Create a chart for yourself like the one below and fill in the blanks

oragn	what is secreted	digested	absorbed	motility	how is function regulated
mouth
esophagus
stomach
small intestines
(liver)
(pancreas)
large intestines

Follow a peanut butter and jelly sandwich and glass of milk as it travels through the sytem-- what happens at each point along the tube?

What would happen if I gave you a shot of CCK?