Digestion II: Leader: Travis Worksheet 2.4 Course: A ECL/BIOL 365 Supplemental Instruction Instructor: Dr. Adams Iowa State University Date: 10/4/16

1.) The ______is where most chemical digestion occurs. This is also the major site of absorption of food material (nutrients), which takes a long time.

2.) The internal surface area of the small intestine is increased by ______.

3.) The large intestine is the major site of ______re-absorption and also compacts ______. Why is the large intestine the most developed in terrestrial vertebrates?

4.) In mammals and many fish, the large intestine terminates in a ______& ______. However, in sharks, amphibians, reptiles, & birds, it ends in a ______.

5.) The ______usually contains bacteria that help digestion. This is a pouch in the wall of the ______.

a. Teleost fish have several of these called ______and few reptiles have this organ. b. In birds and mammals it’s located between the ______and ______intestine. It is most developed in ______. c. In humans, this is known as the vestigial cecum or ______and is very reduced. The function is still debated. 6.) Name the 3 accessory organs connected to the digestive tract. Each of these connects near the start of the ______.

7.) The largest gland in the body is the ______, which lies over the stomach. Name a few of the important functions of the liver.

8.) The ______is a blind sac that stores ______.

1060 Hixson-Lied Student Success Center v 515-294-6624 v [email protected] v http://www.si.iastate.edu (covered by the liver). Bile is needed for the breakdown of ______. Without it, fats would pass through the digestive track ______. What else does bile do? And what other organ does this same function?

9.) The ______produces enzymes to break down food molecules. It breaks down fats to ______and carbohydrates to ______.

10.) Name a few factors that influence the size of the digestive tract.

11.) What conclusion can be drawn from the study on fish in a Panamanian stream, where they compared body size to gut size?

12.) Lampreys do not have a ______to aid in digestion.

13.) Match the digestive system with the correct lineage: fish, amphibian, reptiles, birds, or mammals.