Definition: Excretion is the process by which the body removes waste substances that have been produced by the bodies own cells

The body has 3 organs for excretion. ◦The Lungs ◦The Kidneys ◦The Skin

The function of the Lungs is to take in oxygen gas.

Oxygen is used in the cells of the body to extract energy from food.

The lungs excrete carbon dioxide and water vapour.

The Kidneys are the main excretory organs of the body.

The Kidneys form urine which contains waste products. ◦These include urea, salts and water.

The skin excretes salt and water in the form of sweat.

The lungs excretes carbon dioxide and water vapour.

The kidneys excrete urea, salts and water.

The skin excretes salts and water.

Define excretion. What two substances do the lungs create? Name 3 substances excreted by the

kidneys. Sweat is released from the skin, From

what substances is sweat made. Draw a table naming the bodies 3 organs

for excretion and the substances excreted.

Excess protein is broke down in the cells, as a result of this your body produces urea.

Urea must be removed from the body and is done so in the urinary system

The Urinary System is made up of:

1. The renal arteries and veins 2. The Kidneys 3. The ureters 4. The bladder 5. The urethra

Finish questions pg 46

Purify blood by a process of filtration.

Kidneys filter out urea, salts and water

To control the amount of water in body.

The function of the bladder is to store urine.

The renal arteries are major branches of the aorta.

They carry blood to the kidneys.

This blood contains many impurities which are removed by kidneys.

The renal vein carries blood to the inferior vena cava and blood is then returned to the heart.

The blood is filtered and contains no waste.

The ureter is the tube which carries urine from the kidneys to the bladder.

Remember Ureter Bladder

Urine leaves the body through the urethra.

Remember Urethra away from body