60. Physiology - Regulation of Glomerular Filtration and Renal Hemodynamics

The rate at which blood is filtered by the glomeruli in the kidneys.

Water and small solutes, like salts and glucose, pass through the glomerular capillaries into Bowman's capsule but very little proteins.

The blood pressure within the glomerular capillaries, driving filtration. It starts at 60 mmHg and decreases along the capillary.

Fluid pressure in Bowman's capsule, usually close to 10 mmHg, opposes glomerular filtration.

The pressure exerted by proteins in the plasma, pulling fluid back into the glomerulus. It increases along the glomerulus capillary.

The pressure exerted by proteins in the filtrate, typically close to 0 mmHg.

Nearly all albumin filtered in the glomerulus is reabsorbed by the proximal tubule.

Large proteins are not typically filtered by healthy glomeruli.

Blood leaving the glomerulus through the efferent arteriole has a lower hydrostatic pressure and a higher colloid osmotic pressure.

The rate at which blood is filtered through the glomeruli in the kidneys. In a normal adult human, GFR is 125 ml/min or 180 L/day.

A measure of the glomerular capillaries' ability to filter. It includes surface area and permeability.

The pressure of the blood within the glomerular capillaries, pushing fluid out.

The pressure of fluid inside Bowman's capsule (the space surrounding the glomerulus), opposing fluid filtration.

The pressure exerted by proteins in the blood, pulling fluid backward into the capillaries.

The pressure exerted by proteins present in Bowman's capsule, a small factor.

A decrease in systemic arterial pressure leads to a decrease in glomerular capillary hydrostatic pressure (Pc), which in turn decreases the GFR.

An obstructed ureter increases Bowman's capsule pressure (Pt), which hinders GFR.

Increased vascular permeability means more fluid leakage from the capillaries; this impacts Pc, influencing GFR.

The glomerular capillary hydrostatic pressure (Pc).

Glomerular Filtration Rate; the rate at which the glomeruli filter blood. Measured in mL/min.

The process by which fluid and small solutes from blood are filtered into the Bowman's capsule.

A point during glomerular filtration where the forces favoring filtration (primarily capillary hydrostatic pressure) are perfectly balanced by forces opposing filtration (primarily fluid pressure outside the capillary).

The amount of blood flowing through the kidneys per minute.

A state where forces favoring filtration are not perfectly balanced by forces opposing filtration.

Filtration Coefficient, a measure of the ability of glomerular capillaries to filter.

Forces favoring filtration (primarily capillary hydrostatic pressure).

Forces opposing filtration (primarily fluid pressure outside the capillary).

Capillary hydrostatic pressure (the pressure of fluid within the capillary).

Capillary fluid pressure in the Bowman's capsule (fluid pressure outside the capillary).

The flow of blood through the kidneys, influencing glomerular filtration

Controlling the rate at which blood is filtered by the glomeruli

Blood vessel carrying blood to the glomerulus; its constriction affects pressure.

Blood vessel carrying blood away from the glomerulus; its constriction affects pressure.

Blood pressure within the glomerular capillaries, driving filtration; affected by afferent/efferent constriction

Opposition to blood flow in the renal blood vessels

The volume of blood flowing through the kidneys per unit time

Describes the relationship between blood flow, pressure, and resistance (Q=P/R): flow is pressure divided by resistance.

The flow of blood through the kidneys and how it affects glomerular filtration rate (GFR).

The equation relating blood flow (Q) to pressure (P) and resistance (R) in renal flow.

Narrowing of the afferent arteriole, which increases resistance and lowers both glomerular blood flow and GFR.

Narrowing of the efferent arteriole, which increases resistance, increases glomerular pressure, and may increase GFR despite decreasing blood flow.

The proportion of plasma entering the glomerulus that is filtered into Bowman's capsule.

When the efferent arteriole constricts, the filtration fraction (FF) will increase as GFR rises, despite reduced renal blood flow (RBF).

When the afferent arteriole constricts, GFR and FF fall, as blood flow into the glomerulus is reduced and filtration is impaired

Regulatory mechanisms built into the kidney to control GFR and RPF.