Distal convoluted tubule

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Distal convoluted tubule

Renal system

Anatomy and physiology

Renal system anatomy and physiology

Fluid compartments and homeostasis

Hydration

Body fluid compartments

Movement of water between body compartments

Renal clearance, glomerular filtration and renal blood flow

Renal clearance

Glomerular filtration

TF/Px ratio and TF/Pinulin

Measuring renal plasma flow and renal blood flow

Regulation of renal blood flow

Renal tubular reabsorption and secretion

Tubular reabsorption and secretion

Tubular secretion of PAH

Tubular reabsorption of glucose

Urea recycling

Tubular reabsorption and secretion of weak acids and bases

Renal tubular physiology

Proximal convoluted tubule

Loop of Henle

Distal convoluted tubule

Renin-angiotensin-aldosterone system

Renin-angiotensin-aldosterone system

Renal electrolyte regulation

Sodium homeostasis

Potassium homeostasis

Phosphate, calcium and magnesium homeostasis

Renal sodium and water regulation

Osmoregulation

Sodium homeostasis

Antidiuretic hormone

Kidney countercurrent multiplication

Free water clearance

Renal endocrine functions

Vitamin D

Erythropoietin

Acid-base physiology

Physiologic pH and buffers

Buffering and Henderson-Hasselbalch equation

The role of the kidney in acid-base balance

Acid-base map and compensatory mechanisms

Respiratory acidosis

Metabolic acidosis

Plasma anion gap

Respiratory alkalosis

Metabolic alkalosis

Assessments

Distal convoluted tubule

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Distal convoluted tubule

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A group of investigators are studying the physiologic changes of urine as it passes through the distal convoluted tubule (DCT). Which of the following is true regarding the functions and transporters of DCT?  

Memory Anchors and Partner Content

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First Aid

2016

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Transcript

Content Reviewers

Rishi Desai, MD, MPH

Contributors

Evan Debevec-McKenney

Justin Ling, MD, MS

If we take a cross-section of the kidney, there are two main parts, the outer cortex and the inner medulla.

If we zoom in, there are millions of tiny tubes called nephrons which go from the outer cortex down into the medulla and back out into the cortex again.

Nephrons filter out harmful substances in the blood so that we can excrete them into the urine.

Each nephron is made up of the glomerulus, or a tiny clump of capillaries, where blood filtration begins. These capillaries have very thin walls and they act like a coffee filter. Red blood cells and proteins are large and stay in the capillaries whereas blood plasma and smaller particles get filtered out.

This filtrate, called tubular fluid, collects in a cup shaped structure containing the glomerulus called the Bowman's capsule.

Together, the glomerulus and the Bowman’s capsule make up the renal corpuscle.

The Bowman’s capsule is connected to the renal tubule which has a few segments: the proximal convoluted tubule, the U- shaped loop of Henle with a descending and ascending limb, and the distal convoluted tubule which empties into the collecting duct, which collects the urine.

Zooming in on the distal convoluted tubule, it’s lined by tubule cells which are similar to the one found in the proximal tubule but they don’t have microvilli.

On one side is the apical surface which faces the tubular lumen. On the other side is the basolateral surface, which faces the interstitium or the space between the tubule and the peritubular capillaries.

The peritubular capillaries run alongside the nephron and return solutes and water that were reabsorbed into the interstitium back into the circulation.

The distal convoluted tubule is split up functionally into the early distal convoluted tubule and the late distal convoluted tubule which is very similar to the collecting ducts.

The early distal convoluted tubule is impermeable to water, and the tubular fluid contains more sodium than the tubule cells so sodium ends up flowing down its concentration gradient into the tubule cells using various protein channels.

Sources

  1. "Medical Physiology" Elsevier (2016)
  2. "Physiology" Elsevier (2017)
  3. "Human Anatomy & Physiology" Pearson (2018)
  4. "Principles of Anatomy and Physiology" Wiley (2014)
  5. "Distal Convoluted Tubule" Comprehensive Physiology (2014)
  6. "Distal Convoluted Tubule" Clinical Journal of the American Society of Nephrology (2014)
  7. "Tubular flow activates magnesium transport in the distal convoluted tubule" The FASEB Journal (2018)
  8. "K+–Mediated Regulation of Distal Convoluted Tubule Na/Cl Cotransporter Phosphorylation During Angiotensin II–Induced Hypertension" Hypertension (2016)
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