Life Science- Excretory System Flashcards
Main organs
Kidney, ureter, bladder, urethra (and skin).
Kidney
Blood that contains lots of waste products flows into the kidneys to be filtered. They also control the amount of water that we have in our bodies.
Ureter
Urine made in the kidneys is carried down two tubules called ureters into the bladder.
Bladder
Stores urine
Urethra
A tube that passes out of the body when you urinate.
Skin (not important)
Releases water and sweat
Processes
Filtration of blood, absorption, diffusion and excretion.
Filtration of blood
Blood, contains waste products, is filtered into tiny tubules called nephrons in the kidney. Waste products are dissolved in water, which will eventually form urine. Urine contains poisonous waste products and excess salts and water.
Absorption
As the filtrate passes through the nephrons useful substances such as food molecules, minerals and water are moved back into the blood.
Diffusion
Waste products move by diffusion into the nephrons. This process doesn’t use energy from the cells.
Excretion
The removal of waste products from the blood in the kidneys.
Health issues
Kidney failure, bladder infections and kidney stones.
Kidney failure
Kidneys remove waste products so your body is kept healthy. If excess water and salts aren’t removed from the blood, this build-up can cause strain on the heart. If a person’s kidneys are diseased and stop working, they die. One way to save the person’s life is to link them up to an artificial kidney called dialysis machine, which filters their blood each day. Another way is a kidney transplant, however, it is very difficult to get a kidney and many people die while waiting.
Bladder infections
Sometimes bacteria and other micro-organisms get into the bladder and causes infection. More common in women as their urethra is shorter and closer to the anus than in men. First signs of infection are smelly, cloudy urine and a burning sensation when a person urinates. Bladder infection an be treated using antibiotics.
Kidney stones
One of the most common disorders of the kidney. Sometimes, hard crystals of calcium and salts form inside the kidney (kidney stones). They can block tubules and cause terrible pain. The stones can be as small as a grain of sand or as large as a golf ball. Most kidney stones pass out of the body on their own, without treatment, but others have to removed by surgery. Symptoms include a sharp pain on the side of the body or blood in urine. Can reduce the chance of getting kidney stones by drinking lots of water.
