The Excretory Systems

What is Excretion? Process of eliminating waste products from our bodies.

4 Systems to Eliminate Waste Urinary: Kidneys Respiratory: Lungs Sweat Glands Digestive: Intestines

Sweat Glands About 2 500 000 Discharge sweat through pores Helps control body temperature as well.

Sweat Glands Sweat made up of water other waste materials

The Urinary System Composed of the following: Kidneys Ureters Bladder Urethra

Kidneys 2 reddish bean-shaped organs Eliminate waste and maintain blood balance by filtering blood and producing urine

Kidneys Help maintain the blood balance (mineral concentration and amount of water) Excess in the blood  kidneys will excrete them Amount of urine depends on the concentration of minerals and water in blood. If concentration of minerals is too low, kidneys will excrete more water  mineral concentration If body lacks water and concentration of minerals is too high, kidneys excrete less water and we feel thirsty!!!

Ureters 2 x 25 cm tubes Transport urine produced in kidneys to bladder

Bladder Pear-shaped reservoir with elastic walls Stores urine until urination can hold about 1 L of urine

Urethra Channel/tube 3-4 cm for women About 20 cm for men Transports urine from the bladder to the outside

Composition of urine Water (95%) Urea (breakdown of amino acids) Minerals Substances in excess (vitamins, medication, etc)