Introduction
The human kidney is one of the most important organs of the body. Kidneys play a vital role in maintaining internal balance by filtering blood, removing waste products, regulating water level, and maintaining proper concentration of salts and minerals. Every day, kidneys filter nearly 180 liters of blood to remove toxins and excess substances, producing urine as waste.
This Human Kidney Working Model (3D) is designed as a biology science exhibition project using cardboard and syringes. The model demonstrates how blood enters the kidney, gets purified, and how waste is separated in the form of urine. By using two syringes for blood input and output and one additional syringe for urine flow, the working of the kidney is explained in a simple, visual, and interactive way.
Aim of the Project
The main objectives of this project are:
- To understand the structure and function of the human kidney
- To demonstrate the process of blood filtration
- To explain urine formation in a simple working model
- To create a low-cost 3D biology model using cardboard
- To improve conceptual understanding through hands-on learning
Materials Used
The following materials are used to make this kidney working model:
- Cardboard (base and kidney structure)
- Color paper or paint
- Three syringes (without needles)
- Transparent pipes or IV tubes
- Tissue paper or sponge
- Aluminium foil (optional for structure)
- Glue, tape
- Scissors and cutter
- Marker pens for labeling
Overview of the Human Kidney
Humans have two kidneys located on either side of the backbone. Each kidney is bean-shaped and performs important functions such as:
- Filtering blood
- Removing urea, creatinine, and excess salts
- Maintaining water balance
- Regulating blood pressure
The kidney consists of two main regions:
- Cortex (outer layer)
- Medulla (inner layer)
The functional unit of the kidney is the nephron.
Description of the 3D Kidney Model
The kidney model is mounted vertically on a cardboard base. The kidney shape is cut from thick cardboard and covered with colored paper or painted to resemble a real kidney. Internal filtration structures are shown using tissue paper, sponge, or layered materials to represent nephrons.
Three syringes are connected to the kidney model using transparent tubes:
- Blood Input Syringe (Renal Artery)
- Purified Blood Output Syringe (Renal Vein)
- Urine Output Syringe (Ureter)
Each syringe is clearly labeled for easy explanation.
Structure and Function Explained Using the Model
1. Renal Artery – Blood Input Syringe
The renal artery carries impure blood containing waste materials such as urea, excess salts, and water into the kidney. In the model, this is represented by the first syringe filled with colored water (red or dark color).
When the syringe is pressed, the blood enters the kidney model through transparent tubing, showing blood flow into the kidney.
2. Filtration Unit (Nephrons)
Inside the kidney model, tissue paper or sponge layers represent nephrons. These act as a filtration medium. As blood passes through this region:
- Useful substances are retained
- Waste materials and excess water are separated
This section demonstrates the process of ultrafiltration.
3. Renal Vein – Purified Blood Output Syringe
The second syringe represents the renal vein. After filtration, purified blood exits the kidney through this syringe. The liquid collected here is lighter in color, indicating removal of impurities.
This explains how clean blood returns to the body after filtration.
4. Urine Formation – Urine Output Syringe
The waste materials separated during filtration move toward the urine outlet syringe, which represents the ureter. This third syringe shows urine output.
When pressed or pulled, this syringe demonstrates how urine flows from the kidney to the urinary bladder.
Working of the Kidney Model (Step-by-Step)
- Impure blood is injected through the blood input syringe
- Blood flows into the kidney filtration unit
- Waste materials and excess water are separated
- Purified blood exits through the output syringe
- Waste collects and flows out as urine through the urine syringe
This step-by-step process makes kidney function easy to understand.
Educational Importance of the Model
- Explains complex biological processes visually
- Helps students understand blood purification
- Ideal for biology exhibitions and viva
- Encourages interactive learning
Advantages of Using Syringes in the Model
- Clearly shows fluid movement
- Demonstrates real-time working
- Easy to control flow
- Low-cost and reusable
Health Awareness and Importance of Kidneys
Healthy kidneys are essential for survival. Kidney failure can lead to serious health problems. This model helps create awareness about:
- Drinking sufficient water
- Avoiding excessive salt intake
- Preventing kidney diseases
- Importance of regular health checkups
Advantages of Using Cardboard and Recycled Materials
- Eco-friendly and economical
- Easy to design and modify
- Safe for students
- Promotes reuse and sustainability
Conclusion
This Human Kidney Working Model (3D) Using Syringes effectively demonstrates how kidneys filter blood and form urine. By using cardboard and three syringes, the model simplifies a complex biological process into an easy-to-understand working system.
The project helps students visualize kidney function and understand its importance in maintaining body balance. This model is ideal for science exhibitions, biology projects, and classroom demonstrations.
Healthy Kidneys Mean a Healthy Life.