Download Digestive System w.answers

Name ________________________________
Date _________________
Period ______
Digestive System Webquest
So there you are, sitting at lunch, enjoying some grilled chicken pizza and a few orange wedges.
When you're finished, you take a last drink of milk, wipe your mouth, and head to your next
class. In a few minutes you're thinking about the capital of Oregon or your science fair project.
You've completely forgotten about that pizza lunch you just ate. But it's still in your stomach sort of like a science experiment that happens all the time!
Your digestive system started working even before you took the first bite of
your pizza. And the digestive system will be busy at work on your chewedup lunch for the next few hours - or sometimes days - depending upon what
you've eaten. This process, called digestion, allows your body to get the
nutrients and energy it needs from the food you eat. So let's find out what's
happening to that pizza, orange, and milk.
Site 1: http://www.acm.uiuc.edu/sigbio/project/digestive/index.html
Why Digestion?
1. Name the two main functions of the digestive system.
Convert food materials into useable energy
2. What are two other names for the digestive tract?
Alimentary canal or GI tract
Early Digestion: The Mouth
3. What are the digestive purposes of the mouth?
To bring food in, mechanically break it down and swallow: teeth, tongue, salivary glands (saliva)
4. Name the different types of teeth and describe the function of each.
Incisors, canines, premolars and molars. Incisors cut, canines pierce, premolars and molars
grind.
6. What is a bolus? Small rounded ball of food that can be swallowed.
Early Digestion: The Salivary Glands
7. Name and describe the location of the three pair of salivary glands.
Parotids – just below and in front of the ear near the jaw
Submandibular – on the floor of the mouth
Sublingual – on the floor of the mouth
8. What is the function of saliva?
Begins chemical digestions with enzymes like amylase and reduces friction between food and
the esophagus.
Early Digestion: The Pharynx and Esophagus
9. Describe the process by which food moves through the pharynx and esophagus.
Food leaves the back of the mouth as a bolus and then slides past the epiglottis (covers airway),
through the pharynx. Peristalsis (squeezing of the food) moves the food along the pharynx and
into the esophagus.
Middle Digestion: The Stomach
10. What is the stomach opening called? What is its purpose?
Cardiac orifice (surrounded by gastroesophageal sphincter) – keeps stomach contents from
leaking back into the esophagus.
11. What is the mixture called here?
Chyme – food, HCl, and enzymes – semisolid.
12. What are the stomach folds called? What do they secrete?
Rugae – gastric juice and hydrochloric acid
13. What closes off the stomach from the small intestine?
Pyloric sphincter
Middle Digestion: The Liver, Gall Bladder and Pancreas
14. What are the functions of the liver?
Filters toxins from blood and regulates secretion of bile from gall bladder
15. What is the function of the gallbladder?
Manufactures bile which emulsifies (breaks down) fats, bile is sent to duodenum of intestine.
16. Why is pancreatic juice so important?
Breaks down proteins and carbohydrates, neutralizes the pH of strong acids from the stomach.
Part of endocrine and exocrine system
Late Digestion: The Small Intestine
17. What are the three parts of the small intestine?
Duodenum, jejunum and ileum
18. What is the function of villi?
Increase surface area of the small intestine and absorb nutrients through diffusion into capillaries.
19. What is the function of the duodenum?
Where most of the chemical digestion occurs
Late Digestion: The Large Intestine and Rectum
20. How is fecal material different from chyme?
Thicker and moves much more slowly, less nutrients. Water and salts have been removed by
large intestine.
21. Trace the path of the fecal material.
Ascending colon, transverse colon, descending colon, sigmoid colon.
22. What controls the anus? The internal and external sphincter.
Site 2: http://www.kidshealth.org/teen/your_body/body_basics/digestive_system.html
 Click on “Body Basics: Digestive System” in the blue box.
 Click on each organ and read.
1) Complete the following chart:
Organ
Function
Mechanical breakdown of food, saliva
Mouth
Covers airway when swallowing
Epiglottis
Tube from mouth to stomach that transmits food to stomach.
Esophagus
Pouch where food is further broken down with enzymes, acids and
mechanical mixing
Stomach
Primary site of nutrient absorption into the blood.
Small
intestines
Large
intestines
Where water and salts are removed from the body prior to elimination of
waste
Secretes pancreatic juice and hormones. Helps in digestion.
Pancreas
Filters blood and regulates release of bile into duodenum of small intestine
for emulsifying fats.
Liver
Produces bile for fat emulsification.
Gall
bladder
Label the parts of the digestive system in the diagram below: