ultrafiltration

where does ultrafiltration take place?

Bowman's capsule - nephrons

where does selective reabsorption take place?

distal and proximal convoluted tubules

what molecules are left in the blood?

large molecules and cells

large molecules and cells examples

large proteins (albumen), hormones (insulin), erythrocytes and lymphocytes

what molecules are pass into the renal capsule?

glucose, amino acids, ions, urea and water

how is ultrafiltration achieved?

force small molecules through endothelial wall gaps

afferent arteriole has a....

larger diameter than efferent arteriole

what does a difference in arteriole diameter cause?

high hydrostatic pressure in the capillaries of the glomerulus

what does a high hydrostatic pressure result in?

forcing some substances from the blood into the filtrate in the Bowman's capsule

name structure A

efferent arteriole

name structure B

afferent arteriole

name structure C

lumen of BC

name structure D

podocytes

3 barriers between blood and filtrate:

capillary endothelium, basement membrane and podocytes

name structure A

capillary

name structure B

podocyte

name structure C

basement membrane (barrier 2)

name structure D

podocyte (barrier 3)

name structure E

filtrate in lumen of capsule

name structure F

gap in the capillary endothelium (barrier 1)

name structure G

red blood cell

name structure H

blood plasma

name structure I

podocyte cell of Bowman's capsule wall

what is the basement membrane?

a fine mesh of collagen fibres and glycoproteins

basement membrane function

acts as a filter to prevent the passage of molecules with relative molecular mass >69000

what are podocytes?

finger like projections

how do podocytes act as a barrier?

their shape creates gaps between cells so fluid passes through the gaps and not the cells

what are podocytes preventing entering the filtrate?

larger proteins