Digestive System Model Demonstrating Sequence and Length of Organs

By Laura Hospitál on Mar 31, 2015

This simple model represents the length and sequence of each organ in the digestive system.  It does not model the structure of each organ.
 
As students study the path of food through the digestive system, it is valuable to give them a more concrete sense of the length of each part of the system using this simple model.  Students who understand how different stages of digestion occur as food travels throught he system, will better learn the sequence through which food passes.
 
An overarching theme in biology is the connection between structure and function.  I often stress this with my students.  This model allows for  discussion of both the structure and function of each organ as the class proceeds though the sequence within the digestive system.
 
Please see Sarah Hughes' recent blog, " From Tactile Models to Tactile Graphics" for an excellent model that includes both the structure and the length of the organs of the digestive system. 
 

Related Vocabulary:

  • digestive system - responsible for breaking down food in the body to be used for energy
  • mouth - In the mouth, mechanical and chemical breakdown of food begins as the teeth rip and chew food and the saliva breaks it down chemically
  • pharynx - passage from the mouth to the larynx and esophagus
  • esophagus - a tube that connects the mouth with the stomach - Digestion does not occur in this organ.
  • stomach - Mechanical and chemical breakdown of food continues in the stomach by means of both gastric juices and movement.
  • small intestine - Some digestion and most absorption of nutrients occurs in the small intestine.  'Small" due to the diameter NOT length.
  • large intestine - Waste travels through the large intestine while mineral ions and water are absorbed through the walls of the large intestine to return to the bloodstream. Large due to the larger diameter of the large intestine. 
  • anus - Wastes are eliminated from the body through the anus
 
This activity is adapted from Holt Biology, 2001
Pictures by Ditmar Hospitál

 

Preparation:

Braille and print label of the small intestine on opposite sides of the popsicle stick
  1. Write the following organs on 6 large popsicle sticks in as large print as possible using a permanent marker.

    • MOUTH
    • ESOPHAGUS
    • STOMACH
    • SMALL INTESTIVE
    • LARGE INTESTIVE
    • ANUS
  2. On braille label paper (aph.org) make braille labels of the same organs.

  3. Attach the braille labels on the opposite side of the popsicle sticks.

  4. Attach the popsicle sticks to the rope as indicated to the right.

 
string connected to popsicle sticks "small intestine"
Part                          Length   
Mouth                       8cm (3")
Esophagus             25 cm (10")
Stomach                 15cm (6")
Small Intestine       4-6m (13-20")
Large Intestine       1.2 m (4)
Anus            Place at end of the digestive system.
 

Materials

  • 6 large popsicle sticks
  • Permanent marker
  • 26' rope
  • braille label paper
  • braille writer

 

Procedure

Explain to students that the model you will show them represents the length of the parts of the digestive system.     Have students stand up and walk along the length of the rope beginning with the label for mouth.  Stop at each organ to discuss.  Discuss the lengths of each part of the digestive system and the function of each as you proceed through the system. Always relate structure and function. See vocabulary above   Discuss also the length of time food remains in each part of the digestive system. See below.     Organ                      Length                Amount of time food spends in this part Mouth                      8 cm (3")                5-30 seconds Esophagus              25 cm (10")           5-10 seconds Stomach                  15 cm (6"0)            2-6 hours Small Intestine         4-6 m (13-20')       3-6 hours Large Intestine        1.2 m (4')               up to 2 days Anus.                        n/a                       n/a  

Variations

Include the excellent model of villi that was described in Sarah Hughes recent blog:                           http://www.perkinselearning.org/accessible-science/function-villi-small-...  while discussing the small intestine.   

NGSS Standards:

High School: Structure and Function:
LS1A: Structure and Function:Multicellular organisms have a hierarchical structuralorganization, in which any one system is made up of numerous parts and is itself a component of the next level. (HS-LS1-2)
 
Middle School: Structure, Function, and Information Processing
LS1A: In multicellular organisms, the body is a system of multiple interacting subsystems. These subsystems are
groups of cells that work together to form tissues and organs that are specialized for particular body functions. (MS-LS1-3)
 
digestive system collage
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