Renal Filtration and Barriers Quiz G27

The process by which blood is filtered in the kidneys, removing waste products and excess fluids.

The volume of fluid filtered from the blood into Bowman's capsule per unit of time.

The fraction of plasma that is filtered by the glomerulus into Bowman's capsule.

Tiny pores in the glomerular capillaries that allow water and small solutes to pass through.

The specialized structure in the kidney that filters blood.

The barrier that controls what substances are filtered from the blood into the Bowman's capsule.

The layer of the filtration barrier that surrounds the glomerular capillaries and has a strong negative charge.

The outermost layer of the filtration barrier, composed of cells that are negatively charged and help to prevent proteins from passing through.

The force exerted by proteins in blood plasma that draws water back into the capillaries.

The pressure inside Bowman's capsule, pushing fluid back into the capillaries.

The pressure inside the glomerular capillaries, pushing fluid out into Bowman's capsule.

The pressure inside the afferent arteriole, pushing fluid into the glomerulus.

The pressure inside the efferent arteriole, pushing fluid out of the glomerulus.

A condition where the pressure in Bowman's capsule is increased, reducing filtration.

The pressure difference between the renal artery and renal vein, driving blood flow through the kidneys.

The three main areas of the kidney vasculature that control resistance: interlobular arteries, afferent arterioles, and efferent arterioles.

The sympathetic nervous system, hormones, and local internal renal control mechanisms all influence the resistance within the renal vascular segments, ultimately impacting blood flow.

The outer layer of the kidney responsible for receiving the majority of kidney blood flow.

The inner region of the kidney, receiving only a small percentage of total renal blood flow.

A specialized blood vessel supplying the renal medulla, descending with the loop of Henle and then returning to the cortex.

The sympathetic nervous system can significantly constrict renal arteries, decreasing renal blood flow and GFR.

The ability of the kidneys to maintain a relatively constant glomerular filtration rate (GFR) despite changes in blood pressure.

The amount of urine produced per day, typically about 1.5 liters.

The process of returning filtered substances from the kidney tubules back into the bloodstream.

The increase in urine production due to increased blood pressure.

The ability of the kidneys to regulate sodium excretion based on blood pressure.

The normal range of mean arterial pressure (MAP) where GFR is maintained by autoregulation.

A substance that relaxes smooth muscle, leading to dilation of blood vessels. Examples include nitric oxide (NO) and cyclic guanosine monophosphate (cGMP).

Hormones released by the sympathetic nervous system, such as norepinephrine and epinephrine, can constrict blood vessels in the kidneys, leading to a decrease in glomerular filtration rate (GFR) and renal blood flow.

Endothelin, released by damaged blood vessels, helps with clotting by constricting blood vessels and reducing blood flow to the site of injury.

Angiotensin II, a powerful vasoconstrictor, is produced in the kidneys and circulates in the blood.

While angiotensin II constricts blood vessels, it specifically targets the efferent arterioles in the kidneys, leading to an increase in glomerular pressure and a decrease in renal blood flow.

Nitric oxide (NO), a vasodilator, is produced throughout the body and in the kidneys. It helps maintain normal renal blood flow and excretion of sodium and water.

Drugs that inhibit nitric oxide production can increase renal vascular resistance and decrease GFR, potentially harming kidney function.

Arginine is a precursor to nitric oxide production, which plays a critical role in vasodilation.

Nitric oxide stimulates the conversion of GTP to cyclic GMP, which then causes vasodilation by reducing the concentration of intracellular calcium.

A specialized group of epithelial cells located in the initial portion of the distal tubule, responsible for monitoring sodium chloride concentration and regulating renal blood flow and GFR.

The feedback mechanism that links changes in sodium chloride concentration at the macula densa to adjustments in renal arterial resistance.

A decrease in GFR leads to decreased flow through the loop of Henle, causing increased reabsorption of sodium and chloride. This results in a lower sodium chloride concentration reaching the macula densa.

The macula densa senses the decreased sodium chloride concentration and triggers a series of events to restore GFR.

The signal from the macula densa causes the afferent arteriole to relax, reducing resistance to blood flow, and increasing glomerular hydrostatic pressure.

The signal from the macula densa also stimulates the release of renin from the juxtaglomerular cells.

Renin initiates the renin-angiotensin-aldosterone system (RAAS), ultimately leading to vasoconstriction and increased sodium and water reabsorption.