Osmoregulation

What is the first step of osmoregulation?

Bowman’s Renal capsule- Ultrafiltration

What happens because the afferent arteriole is wider than the efferent arteriole?

It increases the pressure in the blood in the capillary bed with the renal capsule

What is the blood in the capillary bed called?

Glomerulus

What does the increased pressure lead to?

Ultrafiltration

What is Ultrafiltration?

Blood is filtered by a basement membrane and the podocytes of the renal capsule

What molecules are filtered?

Glucose, amino acids, ions and urea

Where are the molecules filtered out into?

The kidney filtrate along with most of the water

Where do cells and larger proteins remain?

n the arterioles

What is the second step of Osmoregulation?

Proximal convoluted tubule- selective Reabsorption

What happens along the length of the approximal convoluted tubules?

Amino acids and ions are actively transported from the filtrate into the blood

What does the active transport ensure?

That all glucose and amino acids are recovered

What does some of the water do?

Returns to the blood by osmosis

What’s the second step of osmoregulation?

Descending limb of the loop of Henle

Where does the loop of Henle go into?

The Medulla

What happens as the loop goes into the medulla?

It’s surrounded by a salt solution that has a gradient

What doe the gradient of the salt solution ensure?

That water moves out of the filtrate by osmosis

What is the fourth step of osmoregulation?

Ascending limb of the loop of Henle

What is the membrane impermeable to?

Water

What happens because the membrane is impermeable to water?

Prevents osmosis back into the filtrate

How are ions transported out of the filtrate?

Active transport

Where are the ions actively transported into?

The medulla

Why are the ions actively transported?

To keep the concentration gradient for the descending limb

What principle is keeping the concentration gradient for the descending limb?

Counter-current principle

What is the fifth step of osmoregulation?

Distil convoluted tubule and collecting duct

What happens in the distil convoluted tubule?

Final alterations of ions can occur

What can the body do when final alterations of ions are done?

The body can recover essential ions before they are lost in urine

What happens in the collecting duct?

Some water can be recovered back into the blood by osmosis

How is dehydration detected?

By osmoreceptors in the Hypothalamus

What happens if the body is dehydrated?

The hypothalamus will release ADH

What is ADH?

Anti diurect hormone

What does the presence of ADH stimulate?

The addition of aquaporins to the wall of the collecting duct

What does the addition of aquaporins to the wall enable?

The recovery of more water by osmosis from Kidney filtrate

What does the osmosis of water from the kidney lead to?

Smaller volumes of more concentrated urine