Transport of Oxygen and Carbon Dioxide

One of the most important functions of the microcirculation is the delivery of O2 to tissue and the removal of waste products, particularly of CO2, from tissue. O2 is required for aerobic intracellular respiration for the production of adenosine triphosphate (ATP). CO2 is produced as a by-product of these biochemical reactions. Tissue metabolic rate can change drastically, e.g., in aerobic muscle in the transition from rest to exercise, which necessitates commensurate changes in blood flow and...

Ventricular Pressure Volume Relations and Energetics

A useful alternative to Fig. 11.4 for displaying ventricular pressure and volume changes is the pressure-volume loop shown in Fig. 11.5a. During the last 20 years, the ventricular pressure-volume relationship has been explored extensively, particularly by Sagawa 1988 , who wrote a comprehensive book on the approach. The isovolumic phases of the cardiac cycle can be recognized as the vertical segments of the loop, the lower limb represents ventricular filling, and the upper segment is the...

Lubrication

Elastohydrodynamic Lubrication

Lubrication is a process of reducing friction and or wear or other forms of surface damage between relatively moving surfaces by the application of a solid, liquid, or gaseous substance i.e., a lubricant . Since friction and wear do not necessarily correlate with each other, the use of the word and in place of and or in the above definition is a common mistake to be avoided. The primary function of a lubricant is to reduce friction or wear or both between moving surfaces in contact with each...