1. www.juniorscience.ie Excretion is one of the characteristics of all living things

2. www.juniorscience.ie Excretion Excretion is the removal of toxic chemical substances Toxic substances are poisonous and can harm the cells of the body if not removed

3. www.juniorscience.ie Excretion OB2-OB23 OB20 understand the structure and function of the urinary system: bladder, renal artery, renal vein, ureter, urethra and kidney OB21 name the products of excretion: CO2, water and urea OB22 understand the function of the skin in the excretion of waste products made in the body OB23 recall that waste products are removed from the bloodstream by filtration in the kidneys in the form of urine, which contains urea, water and salts, and that urine is stored in the bladder before being released from the body

4. www.juniorscience.ie OB20 understand the structure and function of the urinary system: bladder, renal artery, renal vein, ureter, urethra and kidney bladder urethra bladder renal artery renal vein ureter urethra kidney

5. www.juniorscience.ie OB20 understand the structure and function of the urinary system: bladder, renal artery, renal vein, ureter, urethra and kidney bladder urethra renal vein carries blood from kidney renal artery carries blood to kidneykidney filters blood to remove urea ureter transports urine to bladder bladder stores urine urethra releases urine

6. www.juniorscience.ie OB21 name the products of excretion: CO2, water and urea carbon dioxide and water are waste products of the process of respiration in all the cells of the body respiration

7. www.juniorscience.ie the carbon dioxide and some of the water is carried to the lungs by the blood to be excreted o o c o H H o H H o o c

8. www.juniorscience.ie OB21 name the products of excretion: CO2, water and urea urea, which is toxic, is produced in the liver from excess protein excess protein from our food is carried from the gut by blood Toxic urea is removed by and carried by blood to the kidney

9. www.juniorscience.ie OB22 understand the function of the skin in the excretion of waste products made in the body Human skin has sweat glands which lead to pores at the surface – water, salt and a tiny amount of urea is excreted as sweat through these pores section of skin sweat gland blood capillaries pore

10. www.juniorscience.ie OB23 recall that waste products are removed from the bloodstream by filtration in the kidneys in the form of urine, which contains urea, water and salts, and that urine is stored in the bladder before being released from the body

11. www.juniorscience.ie OB23 recall that waste products are removed from the bloodstream by filtration in the kidneys in the form of urine, which contains urea, water and salts water salt urea 1 blood containing water, salts and urea enters the kidney 2 urea, some salts and water are removed from bloodstream by kidney and form urine 3 the urine leaves the kidney in the ureter

12. www.juniorscience.ie OB23 urine is stored in the bladder before being released from the body urethra

13. www.juniorscience.ie Questions

14. www.juniorscience.ie One or Two? How many of each of the following are in the human urinary system? Kidney Bladder Renal artery Renal vein Ureter Urethra HINT blad der urethr

15. www.juniorscience.ie Bladder structure and function Why is the bladder shaped like a plastic bag? Why is the bladder situated below the kidneys? There is a small circular muscle at the exit to the bladder. Why? blad der urethr

16. www.juniorscience.ie Kidney location Which answer places the kidney in the correct area of the body? A B C D B A D C C D B

17. www.juniorscience.ie Kidney The kidney is usually covered in a layer of hard fat. Can you suggest a reason for this?

18. www.juniorscience.ie Kidney All the blood in the body is filtered by the kidney, but when it is cut open there is almost no blood visible. Can you think of a reason for this?

19. www.juniorscience.ie Water - where and when? Water is released from the body by the lungs, the skin and the kidney at different rates under different conditions. How do you think each of the three excretory organs would react on a very hot day? ?

20. www.juniorscience.ie Excretion OB2-OB23 OB20 understand the structure and function of the urinary system: bladder, renal artery, renal vein, ureter, urethra and kidney OB21 name the products of excretion: CO2, water and urea OB22 understand the function of the skin in the excretion of waste products made in the body OB23 recall that waste products are removed from the bloodstream by filtration in the kidneys in the form of urine, which contains urea, water and salts, and that urine is stored in the bladder before being released from the body