Activity
Digestive System Model Demonstrating Sequence and Length of Organs
A hands-on science activity for students who are blind and visually impaired to demonstrate the sequence and length of digestive system organs.
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 through the 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’ 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
Materials
- 6 large popsicle sticks
- Permanent marker
- 26’rope
- braille label paper
- braille writer
Preparation
Write the following organs on 6 large popsicle sticks in as large print as possible using a permanent marker.
- MOUTH
- ESOPHAGUS
- STOMACH
- SMALL INTESTINE
- LARGE INTESTINE
- ANUS
- On braille label paper make braille labels of the same organs.
- Attach the braille labels on the opposite side of the popsicle sticks.
- Attach the popsicle sticks to the rope as indicated to the right.
| Part | Length |
| Mouth | 8cm (3″) |
| Esophagus | 15cm (6″) |
| Stomach | 15cm (6″) |
| Small Intestine | 4-6m (13-20″) |
| Large Intestine | 1.2 m (4) |
| Anus | Place at end of the digestive system. |
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
Include the excellent model of villi that was described in Sarah Hughes’ blog The Function of Villi in the Small Intestine while discussing the small intestine.Â
NGSS Standards
:
High School: Structure and Function:
LS1A: Structure and Function:Multicellular organisms have a hierarchical structural organization, in which any one system is made up of numerous parts and is itself a component of the next level. (HS-LS1-2)
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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)
By Laura Hospitál
This activity is adapted from Holt Biology, 2001
Pictures by Ditmar Hospitál
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