M R S G E N
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?
Human Physiology Lesson 21 Excretion
Waste Products Excretory Product Where produced Where excreted Excreted in
Excretory System
Kidney What is the job of the kidney? What are the name of the blood vessels that supply the kidney?
Kidney Function Filter the blood Preserve water and ions
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
Nephron
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
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.
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)
Preserving and Releasing Water
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
What happens if your kidneys stop working?
3 options Transplant Dialysis machine – haemodialysis Peritoneal Dialysis
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) www.kidneypatientguide.org.uk/site/pdanim.php 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!
Alcohol Effects of Alcohol
Alcohol and Health - Short Term Effects Click on the glass to find out more about these effects...
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...
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?
Past Paper Questions