Related Concept Videos

Reabsorption and Secretion in the Loop of Henle01:17

Reabsorption and Secretion in the Loop of Henle

The thick ascending limb of the nephron loop has Na+–K+–2Cl− symporters in the apical membranes of its cells. These symporters simultaneously reclaim one sodium ion, one potassium ion, and two chloride ions from the tubular fluid. Sodium ions are actively transported into the interstitial fluid at the base and sides of the cell, diffusing into the vasa recta. Chloride ions move through leakage channels in the basolateral membrane into the interstitial fluid and then into the vasa recta.
Reabsorption and Secretion in the DCT and Collecting Duct01:26

Reabsorption and Secretion in the DCT and Collecting Duct

The early phase of the DCT manages the reabsorption of approximately 10-15% of filtered water, 5–10% of filtered sodium, and 5–10% of filtered chloride. This process is facilitated by Na+–Cl− symporters in apical membranes and sodium-potassium pumps, as well as Cl− leakage channels in basolateral membranes. The early DCT also stands out as a site where parathyroid hormone (PTH) stimulates calcium reabsorption, depending on the body's requirements.
The distal part of the DCT, along with the...
Physiology of the Genitourinary System II: Tubular Reabsorption and Secretion01:22

Physiology of the Genitourinary System II: Tubular Reabsorption and Secretion

The kidneys maintain homeostasis through filtration, reabsorption, and secretion. Tubular reabsorption and secretion are crucial in forming urine and regulating electrolytes, water balance, and waste elimination.Tubular Reabsorption and Secretion ProcessesTubular reabsorption is the process that reclaims essential substances such as electrolytes, glucose, amino acids, and water from the glomerular filtrate back into the bloodstream. This is achieved through passive and active transport...
Body Water Content and Fluid Compartments01:19

Body Water Content and Fluid Compartments

Life's biochemical processes occur within aqueous solutions. Solutes are substances that are dissolved within these solutions. The human body contains a variety of solutes, which can differ across various body parts. These can encompass proteins—such as those responsible for clotting and carbohydrate transport—as well as electrolytes. In medicine, an electrolyte is often described as a mineral ion derived from a salt possessing an electric charge. Examples include sodium ions (Na+) and chloride...
Renal Tubule and Collecting Duct01:24

Renal Tubule and Collecting Duct

The renal tubule is divided into three parts: the proximal convoluted tubule (PCT), the Loop of Henle (LOH), and the distal convoluted tubule (DCT).
Proximal Convoluted Tubule (PCT):
The PCT is the initial segment of the renal tubule, extending from the Bowman's capsule that encloses the glomerulus. Its convoluted structure and microvilli-lined cells increase the surface area for reabsorption. The PCT reabsorbs glucose, amino acids, sodium, and water from the filtrate, ensuring essential...
Formation of Dilute Urine01:20

Formation of Dilute Urine

The formation of dilute urine is a critical renal adaptation that maintains fluid balance, particularly during periods of high fluid intake. This process primarily involves the juxtamedullary nephrons. By adjusting the permeability of water and ions in response to physiological conditions, the kidneys can either conserve or excrete water, resulting in concentrated or dilute urine.
Filtrate Osmolarity in the PCT
Initially, as the filtrate passes through the proximal convoluted tubule (PCT), its...