The kidney filters waste products from the blood via glomerular filtration. The other organs perform different functions unrelated to filtering blood.

The ureter transports urine from the kidneys to the bladder. The other options either are not involved in urine transport or represent different parts of the urinary system.

Urine is stored in the urinary bladder until it is excreted. Although the kidney produces urine, the bladder is the correct storage site.

The urethra is the final passageway through which urine exits the body. The other structures are involved in the production, storage, or transportation of urine before excretion.

The nephron is the basic functional unit of the kidney and is responsible for filtering blood to form urine. The other options refer to units in the respiratory, nervous, or liver systems.

The renal cortex houses the majority of the glomeruli and the beginning segments of the nephrons where blood filtration occurs. The other options describe functions that are not performed by the renal cortex.

The descending limb of the loop of Henle is highly permeable to water, allowing for its passive reabsorption. The other segments either have low water permeability or serve different functions in urine formation.

Antidiuretic hormone (ADH) increases the permeability of the collecting ducts to water, thereby enhancing reabsorption. The other hormones listed do not directly affect water reabsorption in this way.

The renal medulla is composed mainly of the loops of Henle and the collecting ducts, which are essential for the concentration of urine. The other options either refer to structures found in the cortex or parts unrelated to the medulla.

Bowman's Capsule surrounds the glomerulus and collects the ultrafiltrate that will be processed into urine. It does not concentrate, actively secrete substances into, or store urine.

The rectum is a component of the digestive system, not the urinary system. The urethra, urinary bladder, and ureter are all integral parts of the urinary system responsible for urine formation and excretion.

The proximal convoluted tubule reabsorbs a majority of the filtered water, glucose, and ions back into the bloodstream. Its primary role is reabsorption rather than secretion, storage, or osmotic gradient generation.

The distal convoluted tubule is a key site for active secretion, where substances such as hydrogen and potassium ions are secreted into the tubular fluid. The proximal convoluted tubule primarily focuses on reabsorption, while Bowman's capsule and the loop of Henle serve different functions.

Aldosterone increases sodium reabsorption in the distal nephron, which in turn promotes water reabsorption, helping to regulate blood pressure. The other options do not correctly describe aldosterone's function.

The renal pelvis functions as a funnel that collects urine from the collecting ducts before it is passed to the ureter. The other regions of the kidney either do not serve as a urine collection area or are part of the urinary excretion pathway.

The counter-current multiplier mechanism establishes a steep osmotic gradient in the renal medulla by exploiting the differences in permeability between the descending and ascending limbs. This gradient is essential for water reabsorption in the collecting ducts and the concentration of urine.

A drop in blood pressure stimulates the kidneys to release renin, which activates the renin-angiotensin-aldosterone system. This results in vasoconstriction and increased sodium retention, mechanisms that work to restore blood pressure.

Chronic kidney disease typically leads to a reduced glomerular filtration rate, which causes waste products to accumulate in the blood. The other options do not accurately reflect the physiological changes associated with kidney dysfunction.

The nephron is divided into specialized segments, such as the proximal tubule, loop of Henle, distal tubule, and collecting duct, each tasked with specific roles in reabsorption or secretion. This specialization ensures precise regulation of the composition of urine.

During dehydration, ADH promotes the insertion of aquaporin channels into the membranes of the collecting ducts, which enhances water reabsorption and helps conserve body water. The other options do not accurately describe the mechanism of ADH action in the kidneys.