The hepatic ultrastructure
We estimate there to be about 1 million lobules in a 2kg human liver, each lobule containing at least 1000 sinusoids 0.5-1.0mm in length, and 700nm in breadth. Thus we estimate there are over 1 billion sinusoids, with blood sluggishly flowing in parallel through each one.
These measurements are estimates, and we await with interest our own and Prof Teutsch's measurements.
This beautiful tree with its myriad of leaves, synthesizing and detoxifying, resembles the liver. The liver in a human is about the size of football, weighs about 2kg, and is made of about one million primary lobules (or acini) which are almost identical, like the leaves of the tree
Cast of portal vein of rat. Alessandra Warren of Concord
This slice of 'nutmeg liver', congested due to heart failure, shows up these lobules (leaves!) approximately 2mm in diameter, with their congested central veins.
This drawing from an old German text book (Diseases of the Liver. F T Frerichs, 1862) shows such a liver, and a magnified lobule that is actually only about 2x1x2mm in size.
This drawing from Beale's microscope in 1880 shows the lobules (leaves) with a portal vein at the upper end carrying blood from the gut.
This second drawing by Beale of a single lobule (real size about 2x1x2mm) with the blood entering the lobule at its periphery, and the tiny network of capillaries, or sinusoids, running through it to the central hepatic vein.
The liverbiopsy needle (from about 40 years ago) is probing the liver in the upper right abdomen.
The core of liver tissue from the needle.
A cast of the approximately 0.5-1mm long sinusoids at x10,000 magnification (with thanks to Eddie Wisse)
A diagram (after Muto of Gifu) showing the fenestrated sinusoids separating the columns of hepatocytes.
A lymphocyte traversing a fenestrated sinusoid with surface probes of dimensions to penetrate fenestrae so contacting hepatocytes leading to immune tolerance.
A cirrhotic rat liver with defenestrated sinusoid
Lifestyles decreasing the porosity of the liver sieve correlate with the incidence of atherosclerosis.