Renal Physiology – Distal Convoluted Tubule & Related Segments

Vocabulary flashcards covering key renal-physiology terms discussed in the lecture segment on the nephron loop, distal convoluted tubule, and collecting duct.

Distal Convoluted Tubule (DCT)

Nephron segment that fine-tunes electrolyte balance; reabsorbs sodium, bicarbonate, and other cations, and actively secretes hydrogen ions.

Nephron Loop (Loop of Henle)

U-shaped portion of the nephron that creates an osmotic gradient by reabsorbing water in the descending limb and salts in the ascending limb.

Collecting Duct

Final tubular segment where water and ion reabsorption are hormonally regulated before urine enters the renal pelvis.

Proximal Convoluted Tubule (PCT)

First nephron segment that performs the bulk of reabsorption of water, glucose, amino acids, bicarbonate, and ions from the filtrate.

Sodium Reabsorption

Active transport process that moves Na⁺ from the filtrate back into the blood, especially prominent in the PCT and DCT.

Bicarbonate Reabsorption

Recovery of HCO₃⁻ from the tubular fluid to maintain systemic acid–base balance, occurring in both the PCT and DCT.

Hydrogen Ion Secretion

Active movement of H⁺ into the tubular fluid, particularly in the DCT, to regulate blood pH and acidify urine.

Cations

Positively charged ions (e.g., Na⁺, K⁺, Ca²⁺) that are selectively reabsorbed along the nephron to maintain electrolyte homeostasis.

Water Reabsorption

Osmosis-driven movement of water from the filtrate into peritubular capillaries; obligatory in the PCT and variable in the nephron loop and collecting duct.