208

Dynamics

of

the Vascular System

7.3.2

Pulse Transmission Characteristics in the Microcirculution

The steady flow

concept assumed for the

microcirculation is in

accordance with the windkessel theory that peripheral vessels act as stiff

tubes. This would protect the small vessels against sudden surges in

flow and rapid changes in pressure.

With the advent of new technology, particularly the servo-controlled

micropipette device for pressure measurement

and

electro-optical

methods for velocity recording, studies of the pulse transmission in

arterioles

and

capillaries became feasible.

Although

significantly

damped, pressure and flow pulses generated by the heart persist into

these vessels.

a

Fig.

7.3.1:

Schematic illustration

of

the pulse transmission path from the ascending aorta

to

the index finger artery.