URINARY SYSTEM

1. What does the urinary system consist of? Name the organs.




2. Complete the text with the words from the box.

travels      carried      removes      back     containing      stores     excrete         forms
           tighten            consists        emptied            swells


The urinary system works with the lungs, skin, and intestines — all of which also __________^1
wastes — to keep the chemicals and water in your body balanced.

The urinary system __________^2 a type of waste called urea from your blood. Urea is produced when
foods __________^3 protein, such as meat, poultry, and certain vegetables, are broken down in the
body. Urea is __________^4 in the bloodstream to the kidneys.

The kidneys are bean-shaped organs about the size of your fists. They remove urea from the blood
through tiny filtering units called nephrons. Each nephron __________^5 of a ball formed of small
blood capillaries, called a glomerulus, and a small tube called a renal tubule. Urea, together with
water and other waste substances, __________^6 the urine as it passes through the nephrons and down
the renal tubules of the kidney.

From the kidneys, urine __________^7 down two thin tubes called ureters to the bladder. Muscles in
the ureter walls constantly __________^8 and relax to force urine downward away from the kidneys.
If urine is allowed to stand still, or __________^9 up, a kidney infection can develop. Small
amounts of urine are __________^10 into the bladder from the ureters about every 10 to 15 seconds.

The bladder is a hollow muscular organ shaped like a balloon. The bladder __________^11 urine until
you are ready to go to the bathroom to empty it. It __________^12 into a round shape when it is
full and gets smaller when empty.

3. Which part of the urinary system is being described?

1. Bean-shaped organs of excretion, each about the size of a fist; they filter the blood and form
urine.

2. Microscopic functional units of the kidney; by working with blood vessels, they filter the blood
and balance the composition of urine.

3. The expanded upper end of the ureter that receives urine from the kidney.

4. The tube that carries urine from the bladder to the outside of the body.

5. The fluid excreted by the kidneys. It consists of water, electrolytes, urea, other metabolic
waste, and pigment. A variety of other substances may appear in it in cases of disease.

6. The main nitrogen-containing waste product in the urine.

7. The organ that stores and eliminates urine excreted by the kidneys.

8. The tube that carries urine from the kidney to the bladder.