Flashcards · Biology · The Kidneys
The Nephron and the Formation of Urine
-
Where does filtration take place?
In the glomerulus and Bowman's capsule.
-
Why is the pressure high in the glomerulus?
The vessel leaving is narrower than the vessel entering.
-
Which molecules stay in the blood?
Blood cells and large proteins.
-
Which molecules are filtered out?
Water, glucose, urea and ions.
-
What is the liquid in Bowman's capsule?
The filtrate.
-
How is glucose reabsorbed?
By active transport.
-
Why is energy needed for glucose reabsorption?
The glucose is moved against its concentration gradient.
-
How much of the glucose is reabsorbed?
All of it, normally.
-
How is water reabsorbed?
By osmosis.
-
Where is water reabsorbed?
In the loop of Henle and the collecting duct.
-
Is urea reabsorbed?
No.
-
Why is the urea concentrated in urine?
Water is reabsorbed, but urea is not.
-
Why does the proximal tubule have many mitochondria?
To supply energy for active transport.
-
What is in the urine?
Urea, excess ions and excess water.
-
Is filtration selective?
No, it depends only on size.
-
Common mistake about the kidney?
Saying that all the water is reabsorbed. Some leaves as urine.