Kidneys play an important role in urine formation through processes like ultrafiltration, selective reabsorption, and secretion. Ultrafiltration forces small molecules like water, glucose, and salts through the basement membrane into the nephron. Through selective reabsorption, the kidneys regulate the levels of water, salts, and other solutes in the blood to maintain homeostasis. The hypothalamus and pituitary gland control the release of antidiuretic hormone, which regulates the amount of water in the blood. The kidneys also help control glucose and salt levels in the blood.

1. Kidneys in Urine FormationPg 226-229Urine Formation

2. Processes in Urine Formation*Ultrafiltration*Selective reabsorptionSecretionExcretion2

3. UltrafiltrationProcess whereby small molecules such as water, glucose, amino acids, sodium chloride and urea in blood are forced through the basement membrane of the Bowman's capsule and into the nephron at high pressure. 3

4. Selective reabsorption4http://www.hcc.uce.ac.uk/physiology/selective%20reabsorption2.gif

5. 5http://www.biologymad.com/resources/kidney.swf

6. Kidney as OsmoregulatorsPg 230 - 231Osmoregulation

7. Definition of osmoregulationIs the control of water and solute levels (e.g. salt, sugar) in the blood to maintain a constant water potential in the body

8. What controls amount of water in the blood?Controlled by vasopressin or antidiuretic hormone (ADH).Produced by a region called hypothalamus of the brain.Released by the pituitary gland of the brain.PituitaryHypothalamus regionmmmmmmmmmmmmmm

9. How to control amount of water in the blood?

10. 10

11. How to control amount of glucose in the blood?

12. How to control amount of salt in the blood?