13 Factor Affecting GFR (Glomerular Filtration Rate)

Glomerular filtration is define as proess of extracting water and solutes from the blood and form urine. Glomerular filtration rate is 90-120 ml/min approx. The rate at which glomerular filtration occur is called glomerular filtration rate. There are many factors that affect glomerular filtration rate that are listed below.

Quantity of blood flow 

Glomerular filtration is directly proportional to amount of blood enter in glomerulus. Approx. 1.3 liter of blood pass through glomerulus each minute. When blood flow rises it increases glomerular filtration rate. It means more blood enter in glomerulus, more substance get filter out.

Systemic arterial pressure 

Systemic arterial pressure is define as pressure exerted by blood on blood vessels. Normal arterial blood pressure is 120/80 mmHg. When it rises glomerular filtration rate increases. On low arterial blood pressure, GFR decreases.

Hormonal influence 

Anti-diuretic hormone and atrial natriuretic hormone function as regulation of blood pressure by maintaining excretion and reabsorption of substances. It affect Glomerular filtration rate.

Contraction of Afferent Arteriole 

Afferent arteriole bring blood to the glomerulus. During contraction less blood enter in glomerulus and GFR decreased.

Contraction of Efferent Arteriole 

Efferent arteriole contraction result in low blood pressure impacting on afferent arterole blood pressure. It results as low blood pressure causing decrease GFR.

Permeability of capillary membrane 

Permeability is define as fluid exchange rate between capillaries and blood vessels. Increased permeability increases GFR. Permeability increases during infection, foreign particles and hypoxia etc.

Sympathetic stimulation 

Sympathetic stimulation include stimulation from central nervous system via epinephrine. It causes constriction of blood vessels resulting in high GFR. It also increase heart rate, breathing rate and sweating.

Surface area of capillary membrane 

Increased surface area allow more blood to filter out. When surface area of the capillaries increases GFR rises. 

Glomerular capillary pressure 

It is define as pressure exerted by blood on capillaries of glomerulus. When more pressure is exert on capillaries more passive filtration will take place. It is also called a driving force of filtration. 

Hydrostatic pressure in Bowmans capsule 

Hydrostatic pressure is constant pressure in kidney occur in edema, kidney obstruction when fluid volume is not transmitting and beome stagnant. During this, glomerular filtration rate is decrease.

Colloidal osmotic pressure 

It is the pressure exerted by protein on the glomerulus. Protein molecule obstruct in the normal blood filtration process. Therefore, when colloidal osmotic pressure increases glomerular filtration rate is decreased.

Tubuloglomerular feedback 

It is regulatory mechanism of GFR. When sodium chloride increases in blood. It stimulate adenosine from ATP which decreased blood flow to kidney by contraction of afferent arteriole.

Disease condition 

In various kidney diseases GFR decreases such as nephrotic syndrome, glomerulonephritis, kidney failure GFR is decreased.

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