Excretory Products and their Elimination

Biology · Class 11

Simulation · Biology · Class 11

A day of filtrate, balanced

"A day of filtrate, balanced" is a free, interactive Class 11 Biology simulation for NEET, built on the lesson "Reabsorption and secretion" in Excretory Products and their Elimination. Meher's kidneys make 125 mL of filtrate a minute, 180 L a day. Move the slider and watch how much of it would leave as urine, in one-litre bottles. GFR 125 mL/min × 1440 min = 180 L a day. With about 1.5 L of urine, the tubules must reabsorb nearly 99 per cent of the filtrate.

From the lesson Reabsorption and secretion in Excretory Products and their Elimination. Change the values and watch what happens.

A day of filtrate, balancedBiology · Class 11

The idea behind it

NCERT §16.2

  • About 180 litres of filtrate are formed a day but only about 1.5 litres of urine are passed, so nearly 99 per cent of the filtrate must be taken back by the renal tubules. This is reabsorption.
  • The epithelial cells of the different tubule segments reabsorb by active or passive mechanisms.
  • Glucose, amino acids, Na⁺ and similar substances are reabsorbed actively; nitrogenous wastes are absorbed passively.
  • In the initial segments of the nephron, water is also reabsorbed passively.
  • In secretion, tubular cells add substances such as H⁺, K⁺ and ammonia to the filtrate.
  • Secretion is an important step too, because it keeps the ionic and acid–base balance of the body fluids.

Questions

2 answers

What does the "A day of filtrate, balanced" simulation show?
Meher's kidneys make 125 mL of filtrate a minute, 180 L a day. Move the slider and watch how much of it would leave as urine, in one-litre bottles.
Is this simulation free?
Yes. It is free and runs in the browser on a phone or a laptop. It belongs to the lesson "Reabsorption and secretion" in Excretory Products and their Elimination (Class 11 Biology).

Embed this simulation

Free, with a link back

Teaching this idea? Put the simulation on your own page or LMS with this code.