Flashcards in Formation of filtrate Deck (24)
What is the ultrafiltrate?
Blood filtered as it enters from glomerulus into the Bowman's capsule
What is the diameter of the glomerular capillaries?
What is the length of the glomerular capillaries?
19 km in total
1 nephron = 1 cm
What is the surface ares of the capillaries?
1 metre squared
What is the histology of the filtration barrier on the side of the glomerulus?
Endothelial cells contain endothelial pores
Allow small molecules to move across the filtration barrier
Fenestrae can be plugged with glycocalyx
Glycocalyx is attached to the basal lamina
What is the role of the glycocalyx?
Prevent macromolecules from entering Bowman's capsule
What is glycocalyx made of?
Glycoprotein - polysaccharide covering
What is the basal lamina made up of?
Negatively charged glycoprotein sheets
What is the histology of the filtration barrier on the side of the Bowman's space?
Glomerular capillary is surrounded by podocytes
Between the podocytes is a diaphragm made by the protein nephrin
How do the podocytes surround the glomerular capillaries?
Podocytes are made up of arm-like structures called primary processes
The primary processes -> secondary processes -> finger-like projections that extend over all capillaried to form a sheet
What is the diaphragm of podocytes made up of?
The protein nephrin
What disease is caused by a mutation in the protein nephrin?
Congenital nephrotic syndrome
How wide is the diaphragm of the podocytes?
Which factors determine glomerular filterability of molecules?
How does electrical charge determine filterability of a molecule?
Filtration membrane is made up of negatively charged glycoproteins
Repels negatively charged solutes
Attract positively charged solutes
How does molecular weight determine filterability of a molecule?
Small molecules are freely filtered
As molecules increase in size - filtration ratio decreases
What is the equation for net ultrafiltration pressure?
Net ultrafiltration pressure = net hydrostatic pressure - net oncotic pressure
What creates net hydrostatic pressure in the capillaries?
What creates net oncotic pressure in the capillaries?
What is the equation for net hydrostatic pressure?
Glomerular hydrostatic pressure - Bowmans space hyrdrostatic pressure
What happens to the net hydrostatic pressure as you go from the afferent to the efferent arterioles?
Net hydrostatic pressure = net oncotic pressure
What does net hydrostatic pressure do?
Drives filtration of salt, water and other components from the glomerulus to the Bowman's space
What happens when net hydrostatic pressure = net oncotic pressure?
No filtration happens