Max-Born-Institut Berlin (MBI)

Fig 46.
Effect of mean blood flow velocity in venules on the growth rate constant
(s-1) of white bodies: results from seventeen experiments. Diameter
of the venules (in µm) : open circles 40-49; left half filled 50-
59; right half filled 60-69; closed circle > 70.
24
Max Born • Gustav Born
Fig 47.
Growth rate constant of platelet thrombi as a
function of blood flow velocity. (from Richardson,
P. D., (1973). Nature (Lond.), 245, 103-
104).
understanding of cell mechanics, particularly through knowledge of the membrane channels
that transport ions, of other transmembrane structures that transmit information (receptor
signalling) and of cytoskeletal components that link to these structures, we have come to
recognise the enormity of the co-ordinated processes responsible for the state of a cell at any
given instant. Thus, so much needs to be known about a cell at any moment to be able to predict
changes in its state that at present we do not have methods which might provide the information
without disturbing what the cell would do if we did not interrogate its current state”
(Richardson, 2004).
Ion channels permit the selective exchange of sodium and potassium across cell membranes
otherwise impermeable to these ions. The channels are complicated, selective structures with
gates which are open and shut by chemical activators. Each gate is in one of two states, open
or shut. Only the numbers of open and shut gates are statistically measurable, not the state of
the individual gate. Another statistical phenomenon is the quantal release of the neurotransmitter
acetyl choline from small vesicles inside nerve endings [41]. Quantal release is individually
demonstrable but not predictable, and measurable only when occurring together in lar-