Kidney

Excretion nitrogenous waste

Animales más normales: urea

birds, reptiles, insects...: uric acid

Aquatic: Ammonia

Functions

Nephrons inside kidney filter blood. Happens in 3 steps

Water balance

Remove metabolic waste

Blood filtration

1) Ultrafliltration

2) Selective Reabsorption

3) Osmoregulation: control of water balance

Happens in Bowman´s Capsule

Basement membrane barrera entre la arteria and the podocytes. Restricts el paso de red blood cells and large proteins so they se quedan en la blood.

Works with high pressure

Happens in proximal and distal tubule

Works with active transport

Mineral ions, vitamins, glucose, amino acids are transported back to the blood.

Salt Gradient

Water Reabsoption

Happen in Loop of Henle

As the loop goes into the medulla it becomes hypertonic (salty)

So when limb ascends it looses salt, stabliching gradient.

When the limb is descendign it looses water.

Happens in collecting duct

As collecting duct goes into the medulla, because of the hypertonic, water moves out

Water will be reaborbed back into the blood.

Controlled by the hormone of dehydration, ADH. Less ADH, less water reabsorbed