# Jumătate de milimetru pe secundă / Half a Millimetre per Second

> Interactive biophysical explainer on cardiovascular hemodynamics, the equation of vascular continuity, and Fick's law of oxygen diffusion in the microcirculation.

- Canonical URL (RO): https://mariuscomper.uk/jumatate-de-milimetru/
- Canonical URL (EN): https://mariuscomper.uk/jumatate-de-milimetru/en/
- Markdown format (RO): https://mariuscomper.uk/jumatate-de-milimetru/index.md
- Markdown format (EN): https://mariuscomper.uk/jumatate-de-milimetru/en/index.md

## Core Topics
- Hydrodynamic Equation of Continuity: Q = A * v
- Total cross-sectional area expands from the aorta (4.5 cm²) to the capillary bed (3,500–4,500 cm²)
- At Q = 5.0 L/min, mean velocity calculates to about 185 mm/s in the aorta and 0.19–0.24 mm/s in the capillary bed
- Fick's Law of Passive Gas Diffusion; the classic ~0.25-second value refers to pulmonary equilibration, not a universal systemic threshold
- Erythrocyte single-file viscoelastic deformation in 5–6 µm capillaries
- Fåhræus-Lindqvist Effect and apparent viscosity reduction in microvessels
- Capillary Refill Time (CRT) physiological baseline (< 2.0 s)