1. M R S G E N

2. Recap What is respiration?
How is the movement and sensitivity of an organism controlled?
What are the main protein molecules involved in digestion?
What is homeostasis?
Where are nutrients absorbed from and to?

3. Human Physiology Lesson 21
Excretion

4. Waste Products Excretory Product Where produced Where excreted
Excreted in

5. Excretory System

6. Kidney What is the job of the kidney?
What are the name of the blood vessels that supply the kidney?

7. Kidney Function
Filter the blood
Preserve water and ions

8. The Male Urino-Genital System
Main vein (vena cava)
Main artery (aorta)
Renal artery
Renal vein
Right kidney
Left ureter
Bladder
Sphincter muscle that controls the release of urine
Urethra
Urine

9. Nephron

10. The Kidney Filter the blood Reabsorb all of the glucose
Reabsorb the ions needed by the body
Reabsorb water needed in the body
Release urea, excess ions and excess water as urine

11. The Kidneys - Internal Structure
Cortex
Nephron - where blood is filtered and urine is formed. Each kidney has about one million nephrons.
Pelvis - a chamber that collects urine from the kidney tubules and funnels it into the ureter.
Ureter
Medulla - consisting of many ‘cone-shaped’ pyramids.

12. Diagram of a Kidney Cut in Half
Your kidneys ‘clean’ the blood by filtering it about 300 times a day. Millions of microscopic tubes called nephrons do this job One very highly magnified nephron is shown in this diagram...
Bowman’s capsule (cup shaped)
Nephron
Glomerulus (bunch of capillaries enclosed by a Bowman’s capsule)
Renal artery (carries unfiltered blood, with waste chemicals, to the kidney)
Tubule (water is reabsorbed here)
Collecting duct (Nephrons drain into here)
Renal vein (carries cleaned, filtered blood, away from the kidney)
Ureter (Peristalsis pushes urine to the bladder)
Note: the nephron is shown at an exaggerated size in this diagram.
Urine (to the bladder)

13. Preserving and Releasing Water

14. Quick Quiz Name the artery that enters the kidneys
Name a molecule too large to fit into the nephron
How do ions move out of the nephron?
What is selective reabsorption?
Where is urea produced?
Name another molecule produced in this organ

15. What happens if your kidneys stop working?

16. 3 options Transplant Dialysis machine – haemodialysis
Peritoneal Dialysis

17. Dialysis V’s Transplants
Weekly treatments, sometimes more frequent. Temporary fix
Permanent -but a chance of rejection
Diet needs to be controlled – in relation to amount of fluid, protein, salt. No high potassium foods e.g. banana
Risks associated with an operation
Shortage of dialysis machines (peritonal dialysis)
Shortage of organs of correct tissue match -in future transgenic organs may be available (BSE?)
Drugs needed while on the machine to stop blood clotting
Immunosuppressant drugs needed for life –lowers resistance to disease
Expensive, machine, nursing staff, hospital etc
Cheaper in the long run!

18. Alcohol
Effects of Alcohol

19. Alcohol and Health - Short Term Effects
Click on the glass to find out more about these effects...

20. Alcohol and Health - Long Term Effects
Move the cursor over the different areas of the body to find out more about the long term effects of drinking alcohol...

21. Questions How will the kidney respond
If you drink a lot on a cold day?
If you exercise vigorously?
How do water and urea leave the blood into dialysis fluid?

22. Past Paper Questions