Ultrafiltration

Question 1

What is ultrafiltration?

Answer 1

• Filtering out of substances out of the blood at the molecular level

Question 2

How does ultrafiltration work?

Answer 2

• High hydrostatic pressure
• afferent arterioles is wider than the efferent arterioles
• small molecules are forced out into the Bowsman’s capsule to form the filtrate
• Large molecules do not fit through the gaps
• Gaps in capillary walls
• Gaps in the capillary membrane
• Gaps in the podocytes
• e.g. Red Blood cells, proteins

Question 3

What 3 layers do molecules have to pas through in order to move from the blood into the renal filtrate?

Answer 3

• the walls of the capillaries in the glomerulus
• the basement membrane of the renal capsule
• special cells called podocytes

Question 4

What substances would stay in the blood?

Answer 4

• Red Blood cells
• White Blood Cells
• platelets
• most of the plasma proteins

Question 5

What substances would leave the blood?

Answer 5

• water
• urea
• glucose
• amino acids
• inorganic ions
• sometimes hormones

Question 6

What is the basement membrane made out of?

Answer 6

• collagen and glycoproteins

Question 7

What does the basement membrane do?

Answer 7

• Most of the molecules found in the blood plasma are small enough to pass through the basement membrane

Question 8

What is the structure of podocytes?

Answer 8

• Additional layer
• They have extensions called pedicles that wrap around capillaries, forming slits

Question 9

What do podocytes do?

Answer 9

• They ensure that any blood cells or large proteins that did get across the basement membranes do not enter the filtrate

Question 10

What is a glomerular Filtration Rate?

Answer 10

• The volume of blood filtered through the kidneys in a given time.
• It gives an idea of how well the kidneys are working.