The body may be considered as a system of collapsible tubes: the capillaries, venules, veins, the ducts of glands, the gastrointestinal and genito-urinary tracts and the smaller airways. All of these are arranged in individual dynamic systems and thus it is daunting to attempt to explain the physics of their behaviour. In the arterial system, flow is generally continuous though pulsatile, whilst in the veins and capillaries it is intermittent. Furthermore the diameters of individual vessels, the cross-sectional shapes, flow rates and transmural pressure gradients of the capillary and venous systems are changing all the time. In the venous system, the technique of video-phlebography has enabled the study of the numerous venous pumps in the leg and venous return back up to the heart. The research for this book has shown that, contrary to conventional teaching, during inspiration in the supine position the inferior vena cava tends to collapse at the level of the diaphragm with corresponding reduction of flow. It was also discovered that the venous footpump was activated by weight-bearing, was independent of muscular action and was able to dislocate a column of blood up to the heart against the force of gravity. This book discusses the physiology of circulation, concentrating especially on peripheral and central venous physiology. Further chapters considering venous pathology and the discussion of intermittent pneumatic compression include consideration of venous thrombosis, injury (including fractures), swelling, ischaemia and bone healing. Using this knowledge the authors of this book developed a simple pneumatic device, which intermittently compresses the foot, flattens the planar arch and mimics the plantar effects of walking. Developed mainly with the hope of reducing venous thrombosis in the immobilized patient, it also reduces pain and swelling and is capable of increasing pedal flow in those with arterial insufficiency.

Table of Contents:
Part 1 Methods of investigation: phlebography; video-phlebography; Doppler ultrasound. Part 2 Circulation physiology: the microcirculation; vasomotion; the micro-anatomy of tissues; capillary flow control - the hyperaemias; critical closing of capillaries - compartmental syndromes; lymphatic return. Part 3 Peripheral venous physiology: the foot; orthostasis; deep vein conduits of the leg; superficial vein conduits of the leg; venous pumps; vein conduits and venous pumps in the arm; techniques of limb bandaging in relation to the venous pumps. Part 4 Central venous physiology. Part 5 Venous pathology: varicose veins; post-phlebitic syndrome. Part 6 Intermittent pneumatic compression: assisted venous return; venous thrombosis; thrombosis after fractures; the A-V impulse system after fractures; pain and swelling; compartmental pressure syndrome; ischaemia; leg posture in ischaemia and after injury; bone healing. Part 7 Principles of flow in collapsible tubes, venous hydrodynamics: collapsibility; compressive zones; variations in time; the venous system; the respiratory pump; does inspiration increase the flow of blood returning to the heart?. Appendices: peripheral venous embolism; Doppler/footpump test for incompetent perforating veins; post-traumatic peripheral pains - hypothesis; deep venous thrombosis in the foot and hand, plantar fasciitis & Sudeck's dystrophy; venous bone pump, bone as a flexible perfused sponge; instructions for the conservative treatment of venous insufficiency.