Excretory System Readymade Science Working Project & Model in Biology with Multicolor Running Lights(with Printed Report)

Step by step 9 steps

1. 1

   Draw the spine down the middle of the board. Mark the kidneys on either side of it just below the lowest ribs, with the right kidney a little lower than the left because the liver sits above it.

2. 2

   Make and fix the two kidneys. On one, draw or cut a section showing the cortex, medulla and renal pelvis.

3. 3

   Run the aorta (red) and the vena cava (blue) down beside the spine, with a renal artery and a renal vein joining each kidney.

4. 4

   Run a ureter from each kidney down to the bladder near the bottom of the board, and the urethra below the bladder.

5. 5

   Push the LEDs through in pairs, one on each ureter at the same height, from top to bottom, then two in the bladder and one or two on the urethra.

6. 6
   Build the chaser

   555 pins 8 and 4 to positive, pin 1 to negative, 1 kΩ from positive to pin 7, 47 kΩ from pin 7 to pins 6 and 2 joined, the 10 µF capacitor from pin 2 to negative (long leg to pin 2), and pin 3 to the CD4017's clock, pin 14; the counter's pin 16 goes to positive and pins 8, 13 and 15 to negative.

7. 7

   Connect the outputs Q0 to Q9 (pins 3, 2, 4, 7, 10, 1, 5, 6, 9 and 11) in order from kidney to urethra, so the light flows downwards. For each pair of ureter LEDs, join the two in series with one 330 Ω resistor so a single output lights both, and give each single LED in the bladder and urethra its own 330 Ω resistor to negative.

8. 8

   Switch on and set a slow speed with the timing capacitor, so visitors can follow the flow.

9. 9

   Add an enlarged nephron card beside the model showing the glomerulus, Bowman's capsule, the tubule and the collecting duct.