1. Objectives Students should learn: that urine, containing urea, excess mineral ions and water, is removed from the body by the kidneys that sugar, mineral ions and water needed by the body are reabsorbed into the blood as it passes through the kidneys.

2. Requirements Nephron sheets to label Colours

3. Specification A healthy kidney produces urine by: – first filtering the blood – reabsorbing all the sugar – reabsorbing the dissolved ions needed by the body – reabsorbing as much water as the body needs – releasing urea, excess ions and water as urine. [B3.3.1 c)] Controlled Assessment: B4.5 Analyse and interpret primary and secondary data. [B4.5.3 a)]; [B4.5.4 a) b)]

4. 2 the human kidney p.248

5. Starter – Urea 1 min to extract bullet point list from p. 248 I got 7… but I knew one from last unit! Lesson 2: the human kidney p.248 What is it? Where is it produced? How is it produced? What transports it? Where to? What happens to it?

6. Urea 1.Produced in the liver 2.Excess amino acids are broken down 3.It is poisonous 4.It travels in the blood plasma 5.Kidneys filter it out of the blood 6.Stored in the urine in the bladder 7.Leaves the body in the urine

7. Outcomes Most students should be able to: describe how the kidneys produce urine describe that the kidneys remove urea and regulate the water content of the body. Some students should also be able to: explain the role of the kidney in homeostasis explain in detail that sugar and dissolved ions may be actively absorbed against a concentration gradient in the kidney tubules.

8. Which other organs get rid of waste from the body by excretion? Kidney plus 2… Does not include faeces/digestive system, why not? Excretion is not defaecation!!

9. Waste removal The lungs remove carbon dioxide. The liver converts excess protein into urea. The kidneys remove unwanted substances such as urea, excess water and salt. Several organs are important in removing waste from the body. The skin provides a surface for small amounts of water and salt to move out of the body.

11. Cortex Medulla Pelvis Nephrons Ureter

12. What are the different parts of a kidney?

13. How a kidney produces urine get the sequence right then copy it down A.reabsorbing the dissolved ions needed by the body B.reabsorbing as much water as the body needs C.filtering the blood D.releasing urea, excess ions and water as urine. E.reabsorbing all the sugar

14. How a kidney produces urine get the sequence right then copy it down A.3 reabsorbing the dissolved ions needed by the body B.4 reabsorbing as much water as the body needs C.1 filtering the blood D.5 releasing urea, excess ions and water as urine. E.2 reabsorbing all the sugar

15. The blood is filtered Water dissolved ions (salt), glucose and urea are small enough to pass through Glucose is selectively reabsorbed into the blood What dissolved ions (salt ) are needed by the body are taken back into the blood by selective reabsorption Any water needed by the body is taken back into the blood Urea, excess ions and water travel to the bladder as urine.

16. The blood is filtered Water dissolved ions (salt), glucose and urea are small enough to pass through Glucose is selectively reabsorbed into the blood the dissolved ions (salt ) are needed by the body are taken back into the blood by selective reabsorption Any water needed by the body is taken back into the blood Urea, excess ions and water travel to the bladder as urine.

17. How does the kidney work?

18. What does urine contain? 1 min to list from the book Why is urine yellow? (extension) Where have we met something like this on the course before?

19. What does urine contain? Urea Excess dissolves (mineral) ions Excess water Urobilins (yellow pigments from the breakdown on haemoglobin in your liver) Bile consists of bilirubin and biliverdin, again these are pigments from the breakdown of haemoglobin in the liver

20. Comparing the composition of blood with urine SubstancePresent in blood? Present in filtrate in kidney tubule? Present in urine? Red blood cells Platelets Proteins Glucose Amino acids Urea water Mineral ions Why is urine yellow?

21. How your kidney responds to drinking See graphs p. 249 More water is lost so the concentration of salt decreases as a result of the greater volume.

22. Workbook P. 115-6

23. Extension Control of water balance by ADH

24. Controlling water content

25. Regulating water content

26. Analysing urine Changes in the colour, clarity, pH and the presence of certain substances in urine can help doctors diagnose medical conditions: Protein or red blood cells in urine can indicate kidney damage or disease, as these substances would not normally filter through the glomerulus. Glucose in urine is often an indication of diabetes. A person with diabetes will have a high level of glucose in the blood.