Water and blood pass opposite ways.

Why send blood against the water?

Setting up the mechanism…

Water outlet oxygen potential: 1.00
Blood outlet oxygen potential: 0.00

Fraction of inlet difference transferred: 0.23

Fit the specimen and set conditions before running.

Why send blood against the water?

Opposite flows retain an oxygen-potential difference along a gill lamella. The oxygen gained by blood equals oxygen lost by water in this equal-capacity specimen.

εcounter = NTU/(1+NTU); εparallel = (1−e⁻²ᴺᵀᵁ)/2

What this model simplifies

Equal-capacity passive exchanger; NTU describes area/conductance. Oxygen potentials are normalized comparable driving variables, not blood or water concentrations. No oxygen is created.

Read the source · openstax.org ↗

Put it to work.

Transfer more than 60% of the inlet oxygen-potential difference.

Make it work.

Compare oxygen transfer with opposite and parallel flows.

Run

Fine adjustments 4

Exchange conductance / flow capacityNTU

Opposite flows: 1 yes, 0 parallel

Water inlet oxygen potential

Blood inlet oxygen potential

Water and blood pass opposite ways.

Why send blood against the water?

Loading the experiment…

Figuvo

Understand by doing.

Understanding is something you do.

Figuvo is a place to look inside everyday things, build a connection, and discover the idea behind them.

177 interactive experiments. Each has a working model and a challenge to test what you found.

The original inspiration

Levers & fulcrums The surprising gyroscope The field cannon Inside the human body

Original demonstrations by The Bugged Dev. The teaching models and interactions here are new implementations.

Community builds

New teaching models inspired by public builds shared around Anatomy.

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All experiments

Water and blood pass opposite ways.

Why send blood against the water?

Setting up the mechanism…

Water outlet oxygen potential: 1.00
Blood outlet oxygen potential: 0.00

Fraction of inlet difference transferred: 0.23

Fit the specimen and set conditions before running.

Why send blood against the water?

Opposite flows retain an oxygen-potential difference along a gill lamella. The oxygen gained by blood equals oxygen lost by water in this equal-capacity specimen.

εcounter = NTU/(1+NTU); εparallel = (1−e⁻²ᴺᵀᵁ)/2

What this model simplifies

Equal-capacity passive exchanger; NTU describes area/conductance. Oxygen potentials are normalized comparable driving variables, not blood or water concentrations. No oxygen is created.

Read the source · openstax.org ↗

Put it to work.

Transfer more than 60% of the inlet oxygen-potential difference.

Make it work.

Compare oxygen transfer with opposite and parallel flows.

Run

Fine adjustments 4

Exchange conductance / flow capacityNTU

Opposite flows: 1 yes, 0 parallel

Water inlet oxygen potential

Blood inlet oxygen potential