EXCRETORY SYSTEM

WHAT IS EXCRETION? If you knew there was poison hidden in your house, you would surely do everything possible to find and remove that poison. If you didn't, you and your family would slowly die. How would you find it? How would you remove it? You would probably figure out a system of searching and removing. That is what the excretory system does!!

interesting facts The Human bladder can stretch to hold about 1.5 cups (400ml) of urine. All the blood in our body passes through each kidney 400 times every day. When the bladder is ½ full, our brain tells the bladder to relax and we get the urge to urinate. We can’t control or stop urination until we are 2 years old. Even if 75% of the nephrons are lost, the kidney will still function. It is possible to live a healthy life with only one kidney. Normal urine is sterile (germ-free). It is composed of water, salts, and waste products.

interesting facts The kidneys have 1 million little filters which filter 1.3 litres of blood every minute. That is 1,620 litres every day.  99.9% of the blood passing through the kidneys is reabsorbed back into the blood. We made approximately 1.5 litres of urine per day. A traditional medical practice in India is called urine therapy, and they apply urine to the skin or drink it to cure various health problems. Urine has a lot of urea (waste), and it is a good source of nitrogen for plants. Gardeners often recommend you add 1 cup of urine to 15 cups of water and apply it to pot plants and flower beds to help them grow.

interesting facts The ancient Romans used to bleach their clothes with urine. People lost at sea or in the desert for a long time often resort to drinking their urine when no rainwater is available. However, this won't prevent you from dying of dehydration, especially if it causes vomiting. Urine has also been used as an antiseptic. In times of war, when other antiseptics were unavailable, urine, the darker the better, was used on open wounds to kill bacteria. The yellow colour of urine was once thought to come from gold. Alchemists in the middle ages spent a lot of time trying to extract gold from urine. They were of course unsuccessful.

FUNCTIONS OF THE EXCRETORY SYSTEM Filters the blood Removes wastes from the blood Keeps the amount of water and salts in the blood constant Helps to regulate Blood Pressure

PARTS OF THE EXCRETORY SYSTEM

#1 KIDNEY Kidney: filters the blood and removes waste

inside the kidney nephrons

#2 Ureter: Moves the urine to the bladder via peristalsis KIDNEY

#3 KIDNEY Bladder: stores the urine URETER BLADDER

#4 KIDNEY Urethra: when the sphincter relaxes, the urethra carries the urine outside the body. 20 cm in males 4 cm in females URETER BLADDER URETHRA

Problems with kidneys Bladder infections - usually caused by bacteria. More common in women due to their short urethra. 33% of women and 10% of men will have one or more in their lifetime. Enlarged prostate - in men, this can make it difficult to empty the bladder. Incontinence - when urine leaks out of the urethra. Common after natural childbirth. Kidney infections - when a bladder infection ‘backs up’ the ureters and makes it difficult to urinate. Kidney stones - caused by infection and high blood levels of calcium.

Problems with kidneys Have diabetes Have high blood pressure Are obese Risk factors for chronic kidney disease You are more ‘at risk’ of chronic kidney disease if you: Have diabetes Have high blood pressure Are obese Are over 50 years of age Have a family history of kidney disease Smoke Are of Aboriginal descent.

Symptoms of kidney disease Kidney disease is called a ‘silent disease’ as there are often few symptoms. Some signs and symptoms include: Pee more and more often especially at night Blood in the urine Foaming urine Puffiness around the eyes and ankles Pain in the back (under the lower ribs, where the kidneys are located) Pain or burning when passing urine. KIDNEY TRANSPLANT ANIMATION http://www.kidneypatientguide.org.uk/site/TRAanim.php

Lifestyle changes can keep your kidneys healthy Making healthy lifestyle choices can help to keep your kidneys functioning well: Eat lots of fruit and vegetables and grain-based food like bread, pasta, noodles and rice. Eat some lean meat like chicken and fish each week. Eat only small amounts of salty or fatty food. Drink plenty of water instead of sugary drinks. Maintain a healthy weight. Stay fit. Do at least 30 minutes of physical activity that increases your heart rate on five or more days of the week including walking, lawn mowing, bike riding, swimming or gentle aerobics. Don’t smoke. Limit your alcohol to two small drinks per day if you are male or one small drink per day if you are female. Have your blood pressure checked regularly. Do things that help you relax and reduce your stress levels.