R03e（Si-Po　Model of a heart )

Si-Po (Model of a heart )

PURPOSE:

Si-Po is effective when teaching the followings

[mechanism of a human's heart (or a pump)

especially the role of valves in a heart]

[circulatory organ inside the human body]

[Relation between wrist pulse and heart beat]

[mechanism of a pump]

TARGET:

Elementary school students (Grade 6)

Junior high school Students (Grade 8)

CATEGORY:

Biology, Monozukuri(Science craft)

HOW TO MAKE

All parts are shown in Fig.1.

(1) Silicon rubber tube (Outer diameter: 16mm, Inner diameter:12mm, length:90 mm) .... 1 piece

(2) Silicon rubber tube (Outer diameter: 13mm, Inner diameter:9mm, length:7mm) ...2 pieces

(3) Silicon rubber tube (Outer diameter: 9mm, Inner diameter:5mm, length:15mm) ...2 pieces

(4) Silicon rubber tube (Outer diameter: 5mm, Inner diameter:3mm, length:35mm) ...2 pieces

(6) Silicon rubber rod (Diameter: 4 mm, length:20-30mm ) .... 1 piece

(Prepare Valved Tube)

First, as shown in Fig.2, insert a "rod(6)" into "tube(4)"

and Cut off the remaining part.

Then, as shown in Fig,3, make a cut near the closed end of the tube

As shown in Fig.4, insert the Valved Tube into "tube(3)".

Assemble the valved tube, "tube(2)" and "tube(1)" as shown in Fig.5.

(Note: the direction of two valved tubes must be identical.)

HOW TO USE

Students can pump up water using Si-Po.

When the sides of the pump body are squeezed, water flows out from the upper valve.

When the sides are released, the body inflates and water flows in from the bottom valve. (cf. Fig.6)

Students can observe how the valves work.

By connecting Si-Po to the following tubes as shown in Fig.7 ,

a simple model of circulatory organ ( "one heart atrium" - "one heart ventricle") is obtained.

(7) Silicon rubber tube for an heart atrium

   (Outer diameter:10mm, Inner diameter:8mm, length:100mm)

(8) Silicon rubber tube for blood vessel

   (Outer diameter:9mm, Inner diameter:7mm, length:500mm)

APPLICATION

A model of a human heart can be made using two Si-Po as shown in Fig.9.

After explaining the structure of the human heart and circulatory system,

you can dismantle it

and you can show that a human circulatory system is composed of only one long loop with two pumps in it.

REFERENCES

Masahiro KAMATA and Ryoko YAMAGISHI, "Development and Educational Practice of Heart Models Made of Silicon Rubber Tubes", Journal of Science Education in Japan, 33, pp. 90-97、 2009

Masahiro Kamata and Ryoko Yamagishi, “Plastic pump models the heart”, Physics Education 43, pp.245-247, 2008