Glomerular Filtration Rate (GFR)

GFR

the rate at which you blood is filtered each minute

What does GFR depend on first?

Net filtration pressure (10 mmHg)

Net filtration pressure is also known as…

Glomerular capillary blood pressure (GCBP)

What structure is adjusted to help regulate GFR through blood pressure changes?

Afferent arteriole diameter

GFR also depends on…

Glomerular surface area

GFR is also affected by the “leakiness” of the glomerular membrane, also called

holeyness

The kidneys can adjust the ______ in which blood is filtered in the glomerulus.

rate/effectiveness

What happens if GFR is too high?

Fluid flows through the renal tubules too rapidly for them to reabsorb the usual amount of water and solutes

What is a possible result of a high GFR?

Urine output rises

A high GFR can increase the risk of…

chance of dehydration and electrolyte depletion

What happens if GFR is too low?

Too much is reabsorbed

A possible condition caused by low GFR is…

Azotemia

Azotemia refers to

high concentration of nitrogen in blood

GFR is controlled by adjusting which variable?

glomerular capillary blood pressure (GCBP)

GFR changes are regulated….

moment to moment

Which of the following is NOT a homeostatic mechanism controlling GFR?

Digestive regulation

How many main homeostatic mechanisms control GFR?

3

When you constrict the afferent arteriole?

• Diameter: decreases

• Resistance: increases

• Blood flow: decreases

• GCBP: decreases

• GFR: Increases

When you dilate the afferent arteriole….

• Diameter: increases

• Resistance: decreases

• Blood flow: increases

• GCBP: increases

• GFR: increases