Biology project – Urinary system

Biology project – Urinary system


Some classes ago, our bIology teacher, told us to create a model of the urinary system, using trash, as the image(taken from our teacher’s blogs) shows. The purpose of this, was that we shouldn’t need to buy things and that this trash materials, would have another use. In this project, I’ve worked with Tomás Braun Urien.

As the image, taken from our teacher’s blog, shows we used cans of drinks covered with red paper, to represent the kidneys, as they´re red. Moreover, ureter and urethra were presented in our project with strings. Also, the renal artery and the aorta were made by us with red straws, while the renal vein and the vena cava were made with blue straws. Finally, we use a plastic sac to represent the bladder.


As a last step, we should include each function, of each organ of this system. And this is what we wrote:



  • Kidneys: The kidneys are two bean-shaped organs found on the left and right sides of the body in vertebrates. The kidneys receive blood through the renal artery. The blood reaches the kidney and this one, together with its components(millions of nephrons) start to work. The wastes, such as urea, salt, water and minerals which weren´t extracted from food, are removed from blood and converted by the kidneys (and functional nephrons inside them) into urine, which is drained down a tube by the name of ureter.
  • Nephron: The nephron is the tiny structure in your kidneys which helps to filter your blood. Each of your kidneys contain more than a million of these structures. It removes the wastes(urea, salts, water, minerals) from blood and converts them into urine, which is later passed through the ureter into the bladder.
  • The ureter: The ureter is a large tube that carries urine from the kidney to the urinary bladder. There are two ureters, one attached to each kidney. In the abdomen, the upper half of the ureter is located and the lower half is situated in the pelvic area. In adults, the ureter is about 10 to 12 inches long and it always has thick walls composed of a fibrous, a muscular, and a mucus coat, which is able to contract.
  • The bladder: The bladder is an expandable muscular sac located in the lower abdominal area near the pelvic bones. This one stores and keeps urine before it is excreted out of the body through the urethra. The bladder contracts when it is empty. When empty, the bladder’s muscle wall becomes thicker and the entire bladder becomes firm.
  • The Urethra: Throughout the urethra, the urinary bladder and the outside of the body are connected. Once the bladder becomes full, urine flows through the urethra and leaves the body. The urethra is more than just a urinary duct; it also serves as a conduit for semen and sperm during sexual acts in men.
  • The renal veins: There are two renal veins, the left one and the right one. They branch off the inferior vena cava and drain oxygen-depleted blood from the kidneys. As they enter the kidneys, each vein separates into two parts. The posterior veins drain the posterior section of each kidney, while the anterior veins do this same thing but in the front part. These veins also drain blood from the ureter, which carries urine away from the kidneys to the bladder.
  • The renal artery: The renal artery is one of the two blood vessels which leave the abdominal aorta and enter the kidneys. The renal artery enters through the hilum, and once it does this, it splits into two main branches. These ones each then split into numerous smaller arteries called nephrons, which deliver blood to different areas of the kidneys.
  • The inferior vena cava: The inferior vena cava is a large vein that transports de-oxygenated blood(most of the oxygen has been removed by tissues, and therefore the blood is darker) to the heart from the lower body(legs and lower torso).
  • The abdominal aorta: The abdominal aorta is the largest artery in the abdominal cavity. As part of the aorta, it is a direct continuation of the descending aorta and branches to form the major arteries of the abdomen. It provides blood to the organs and tissues of the abdomen, pelvis, and legs.



Finally, this is our labelled model: