Kidneys

Kidney Function

The kidneys maintain normal blood concentrations of ions and water, regulating various physiological processes.

Filtration

Movement of fluid from blood to the lumen of the nephron, creating a filtrate similar to plasma without proteins.

Reabsorption

The process of moving substances from the lumen of the tubule back into the blood.

Secretion

The selective removal of molecules from blood and their addition to the filtrate in the lumen.

Excretion

The process of removing urine or substances from the body.

Glomerulus

A network of capillaries in the nephron where filtration occurs.

Nephron

The functional unit of the kidney that performs the processes of filtration, reabsorption, secretion, and excretion.

Bowman's Capsule

The part of the nephron that encases the glomerulus and collects the filtrate.

Granular Cells

Cells in the kidney that signal changes in blood pressure by constricting or dilating the afferent arteriole.

Glomerular Filtration Rate (GFR)

The volume of fluid that filters into Bowman's capsule per unit time, average 125 mL/min or 180 L/day.

Homeostasis

The process by which the body maintains a stable internal environment despite external changes.

Nephron Function

The nephron's primary roles include filtering blood, reabsorbing essential substances, and secreting waste.

Reabsorption sites

Major sites of reabsorption include the proximal convoluted tubule and loop of Henle.

Secretion role

Secretion helps eliminate excess ions and wastes from the blood into the filtrate.

ADH

Antidiuretic hormone (ADH) regulates water balance by increasing water reabsorption in the kidneys.

Ureters

Tubes that transport urine from the kidneys to the bladder.

Urinary Bladder

A muscular sac that stores urine until it is excreted from the body.

Escherichia coli (E. coli)

A common bacteria that can lead to urinary tract infections when it enters the urinary system.