Factors determining blood flow through the kidneys

2021-04-30 10:02 PM

Although changes in arterial pressure have an effect on blood flow through the kidneys, the kidneys have a mechanism of action to maintain renal blood flow and a fixed glomerular filtration rate.

Renal vascular flow is determined by the renal vascular gradient pressure (hydrostatic pressure differs between the renal artery and vein), dividing the total renal vascular resistance:

(Renal artery pressure - Renal venous pressure) / Total renal vascular resistance.

Renal artery pressure is equal to systemic arterial pressure, and renal venous pressure averages about 3 to 4 mm Hg under normal conditions. Total renal vascular resistance is determined by the total resistance in individual blood vessels, including arteries, arterioles, capillaries, and veins.

Renal artery resistance consists of 3 main segments: the interstitial artery, the artery of arrival, and the aorta. The resistance of these vessels is controlled by the sympathetic nervous system and the local control mechanism inside the kidney is exchanged later. Increasing the resistance of any of the vessels in the kidney leads to a decrease in blood flow through the kidneys.

Board. The pressure and resistance of blood vessels in the circulation of the kidneys are normal

Conversely, a decrease in vascular resistance increases renal flow if arterial and venous pressure remains constant.

Although changes in arterial pressure have an effect on blood flow through the kidneys, the kidneys act to maintain blood flow through the kidneys and glomerular filtration rates are fixed with arterial pressures between 80 and 170 mmHg.

 

MOST VIEW

Pathophysiology of cardiogenic shock

Urine formation: Reabsorbed glomerular filtration

Air in and out of the lungs: pressure causes the movement of air

Mechanism of urine concentration: osmotic pressure changes in different segments of the renal tubule

Absorption and excretion of potassium through the kidneys

Prothrombin activation: initiates blood clotting

Pulmonary capillary dynamics: capillary fluid exchange and pulmonary interstitial fluid dynamics

Graphical analysis of high-volume heart failure

Estimated renal plasma flow: PAH clearance

Calculate the glomerular filtration rate (GFR): the forces that cause the filtration process

Reduced sodium chloride, dilates arterioles, increases Renin release.

Nephron: The functional unit of the kidney

Ammonia buffering system: excretes excess H + and creates new HCO3

Concentrated urine formation: urea contributes to increased osmotic pressure in the renal medullary

Red blood cells: differentiation and synthesis

Extracellular fluid distribution between interstitial space and blood vessels

The proximal tubule reabsorption: active and passive reabsorption

Origin of lymphocytes: the body's resistance to infection

The endocrine regulates tubular reabsorption

Acidosis causes a decrease in HCO3- / H + in renal tubular fluid: compensation mechanism of the kidney

Physiological anatomy of the kidneys and urinary system

Sodium channel blockers: decrease the reabsorption of sodium in the manifold

Self-regulation of glomerular filtration rate and renal blood flow

The kidneys excrete sodium and fluid: feedback regulates body fluids and arterial pressure

Pathophysiology of fever