glomerulaarfiltratsioonina

Glomerulaarfiltratsioonina is the process by which fluid and small solutes are filtered from the blood into the Bowman's capsule in the nephron of the kidney. This filtration occurs across the glomerular filtration barrier, which consists of the fenestrated endothelium of the glomerular capillaries, the glomerular basement membrane, and the podocytes of the visceral layer of Bowman's capsule.

The driving force for glomerular filtration is the net filtration pressure, which is the sum of the glomerular hydrostatic pressure and the capsular osmotic pressure, minus the colloid osmotic pressure of the glomerular blood and the hydrostatic pressure of the capsular space. Glomerular hydrostatic pressure is the main component of this force, pushing fluid out of the capillaries.

The glomerular filtrate is essentially plasma without large proteins and blood cells. It contains water, electrolytes, glucose, amino acids, urea, and other small molecules. The rate at which this filtration occurs is known as the glomerular filtration rate (GFR). GFR is a crucial indicator of kidney function and is typically measured in milliliters per minute.

Several factors can affect GFR, including blood pressure, hydration status, and hormonal influences. Hormones like angiotensin II can constrict the afferent arteriole, reducing GFR, while others like atrial natriuretic peptide can dilate it, increasing GFR. Maintaining a stable GFR is essential for the body to regulate fluid balance, blood pressure, and waste removal.