Kidneys in Urine Formation

Pg 226-229Urine Formation

Processes in Urine Formation

2

*Ultrafiltration

*Selective reabsorption

Secretion

Excretion

Ultrafiltration• Process 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

Selective reabsorption

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

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

Kidney as OsmoregulatorsPg 230 - 231

Osmoregulation

Definition of osmoregulation

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

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.

Hypothalamus region Pituitary

mmmmmmmmmmmmmm

How to control amount of water in the blood?

10

How to control amount of glucose in the blood?

How to control amount of salt in the blood?