Renal Physiology Quiz: Glomerular Filtration

The process where blood plasma is filtered through the glomerulus in the kidneys to produce a filtrate, the first step in urine formation.

The rate at which fluid is filtered from the blood into the Bowman's capsule in the kidneys.

The specialized capillaries within the Bowman's capsule of the kidney, where filtration of blood plasma takes place.

The three layers of the glomerular capillary wall that act as a barrier to filtration of plasma proteins, but allow water and small solutes through.

The property of a substance to pass through the glomerular filtration barrier and be included in the filtrate.

The size and electrical charge of molecules affect how easily they pass through the glomerular filtration barrier.

The percentage of plasma that is filtered by the glomeruli.

The normal reabsorption of most of the filtered fluid back into the bloodstream, resulting in a small amount of urine being excreted.

The efferent arteriole has a higher resistance than the afferent arteriole, resulting in a higher pressure in the glomerular capillaries, promoting filtration.

The glomerular capillaries are where filtration takes place, and the pressure gradient drives the process.

Vasodilators like nitric oxide increase GFR by relaxing the afferent arteriole, increasing blood flow to the glomeruli.

Vasoconstrictors like norepinephrine reduce GFR by tightening the afferent arteriole, reducing blood flow to the glomeruli.

The pressure difference between the renal artery and the renal vein is mostly due to the resistance in the afferent and efferent arterioles.

The pressure exerted by fluids within the Bowman's capsule of the nephron, which opposes the filtration of blood into the capsule.

The pressure exerted by the blood within the glomerular capillaries, which drives the filtration of blood into the Bowman's capsule.

The pressure exerted by proteins in the blood, which opposes filtration by pulling fluid back into the capillaries.

An increase in the pressure exerted by fluids within the Bowman's capsule directly reduces GFR.

An increase in the arterial plasma colloid osmotic pressure directly increases the pressure in the glomerular capillaries, which in turn can decrease GFR.

An increase in the filtration fraction can cause an increase in the glomerular colloid osmotic pressure, which tends to decrease GFR.

The process where the kidneys automatically adjust blood flow to maintain a stable glomerular filtration rate (GFR) despite changes in blood pressure.

A mechanism by which the renal tubules increase their reabsorption rate when GFR rises.

The volume of urine produced per unit time.

If tubular reabsorption remained constant, a large increase in GFR would lead to a drastic increase in urine output. This could deplete blood volume.

The total volume of blood plasma in the body.

The pressure of blood within the arteries, averaged over the cardiac cycle.

A mechanism by which blood vessels resist stretching during increased blood pressure.

The ability of individual blood vessels to contract in response to increased wall tension or stretch.

The movement of calcium ions into vascular smooth muscle cells, leading to contraction.

Increased vascular resistance resulting from blood vessel contraction, helps prevent excessive increases in renal blood flow and GFR.

A process that helps maintain a stable renal blood flow and GFR in the face of varying blood pressure.

A specialized structure in the kidney that detects changes in sodium chloride concentration in the filtrate.

These cells secrete renin in response to low blood pressure.

The narrowing of the efferent arteriole in response to decreased sodium chloride concentration in the filtrate, raising glomerular pressure.

The release of renin from juxtaglomerular cells in response to decreased sodium chloride concentration.

The process of converting angiotensin I to angiotensin II, which helps to raise blood pressure by constricting blood vessels.

A condition where the renal artery is partially blocked, leading to reduced blood flow to the kidney.

The decrease in the glomerular filtration rate (GFR) that can occur when drugs that block angiotensin II formation are used in patients with renal artery stenosis.

Drugs that block the formation of angiotensin II and help lower blood pressure. They should be used cautiously in patients with renal artery stenosis.