Making and Using a Gel Person to Teach Human Anatomy

Kelly Ludwig Lincoln-Way High School
1801 East Lincoln Highway
New Lenox IL 60451
(815) 485-7655

Objectives:

High school students will use a gel person to:
1. describe the overall body plan of a human
2. identify the major organs of the human body
3. aid in the visualization of scanning imaging
4. describe anatomical planes and directions
5. make transverse sections

Materials Needed:

MAKING A GEL PERSON VISUALIZATION OF SCANNING IMAGING unflavored gelatine (.25 Oz. Envelopes) gel person blue food coloring (optional) plastic or glass (4" x 6") gel person mold (gingerbread man) ring stand or bracket (optional) pasta (assorted shapes & sizes, cooked) flashlight or small lamp vegetables (beans, cauliflower, cooked) white card (8.5" x 11") tray or plate *materials will make two GEL Persons MAKING TRANSVERSE SECTION gel person plastic knife index cards (4" x 6") pencil ruler (15-30 cm, marked in cm) paper towels and disposal bag Strategy:

MAKING A GEL PERSON 1. Obtain two gelatine molds in the form of a person. 2. Mix two envelopes of unflavored gelatine into 1.25 cups of boiling water until dissolved. Add one drop of food coloring. This will give some contrast to the "organs" inside the gel person without losing too much transparency. 3. Pour enough of the warm gelatine solution into the bottom of the mold to just cover the bottom (anterior surface of the person). Place in a refrigerator until it gels (about 30 minutes). Set aside the remaining gelatine solution until Step #5. 4. Place pasta and vegetables in the mold on top of the gel. Use a small floret of cooked cauliflower in the head (to mimic the brain). In the rest of the body, use any or all of these: - several pieces of cooked small elbow macaroni (to mimic hollow organs). - one piece of cooked mostaccioli rigati (to mimic a large hollow organ with an irregular surface). - 2 or 3 canned red beans (to mimic solid organs such as the kidneys). - one short strand of cooked vermicelli (to mimic solid fiber-like organs such as nerves). You might want to coil a piece of this to show how coiled organs show up in a transverse section. *Use other soft materials as you desire in addition to, or in place of, those listed. *Do not use too many pieces. Spread things out a little. You can also put "organs" in the arms and legs as well as the middle part of the body. 5. Fill mold to the top with the remaining gelatine solution. Refrigerate until solid (about 30 minutes). 6. Remove mold from refrigerator and dip in hot water for a few seconds to loosen gelatine. Place a tray or plate over the mold and invert, dropping gelatine form onto tray. Use the gel person as soon as possible. Gel persons can be refrigerated but they do not freeze well. VISUALIZATION OF SCANNING IMAGING 1. Place one gel person on a 4" x 6" plate of glass or transparent acrylic. 2. Clamp the plate (with the gel person on it) to the ring stand. Instead of using a clamp and ring stand, you can simply have a volunteer hold the plate steady. 3. Use a flashlight or lamp to cast a shadow on the white card. Do this by holding the light source above the gel person and the white card below the transparent plate. This demonstrates the principle of standard X-ray photography. 4. Holding the light source in one hand and the white card in the other, rotate the pair around the gel person without changing the distance or angle of your hands. This mimics the action of an axial scanner used in creating CT scans. 5. Discuss how a scanned image can produce a 3D image of the contents of the body or of an individual organ. MAKING TRANSVERSE SECTIONS 1. Lay one index card in front of you so the long side is along the left and right and the short side is at the top and bottom. Use a metric ruler and pencil to mark off one index card into 1cm segments. Start at the top by making a line 1cm from the top and proceed down the card. Number each segment by writing a number along the left edge of the card with your pencil. 2. Place a gel person on the index card that you have just marked off into 1cm sections. It should just fit on the card if the lines are along transverse (horizontal) planes of the gel person's "body". 3. Using a new index card, mark off 1cm lines as you did in Step #1. Now sketch the outline of the gel person on this second card exactly matching the way it lies on the first card. Then sketch in the structures or "organs" you see inside the gel person. Keep the sketch simple but accurate. 4. Beginning at the top of the gel person's head, use a plastic knife to cut a transverse section along the first line on the underlying card. That is, cut a transverse section 1cm from the top of the head. Place this section, inferior side up on a clean index card. Mark the number of the section (#1) along the left edge of this clean card. 5. Continue to cut sections in order: at the 2cm mark, at the 3cm mark, and so on, until the gel person's body is completely sectioned. After marking each section lay it on a clean index cards. Three or four sections should fit on each card. Do not forget to mark the number of each section along the left edge of the clean card as you lay them down. 6. Make a sketch of each section on index cards. 7. Discard your material in the disposal bag. Return usable items (unused cards, pencils, rulers) to the instructor. Performance Assessment:

At the completion of this lesson students will accomplish the following:
1. Describe anatomical position.
2. Identify the major organs of the human body.
3. Locate and describe anatomical planes and directions.
4. Describe the relationship between your original sketch (made before you
cut the gel persons into segments) and the sketches of the transverse
sections.
5. Explain how this "transverse sectional anatomy" improved your
understanding of how the gel person is structured.
6. Explain how this dissection relates to scanning medical images that
might be made of your gel person.

Conclusion:
This activity aids students in understanding and visualizing the mechanics
of scanning imaging as a diagnostic technique.

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