Chapter 20.3, Problem 13BYGO

Summary Introduction

Introduction:

Due to the presence of small vessels, it is hard to measure the pressure in the capillaries. These factors make it difficult to understand the mechanism of the capillary exchange. Thus, the theories of capillary exchange remain disputed. The stereomicroscope observation on the fingernail bed and eponychium has been the basis of study. The blood pressure of capillaries at the arterial end is about 32 mm Hg and 15 mm Hg and is found in the venous end. Due to their small narrow vessels, the blood pressure drops rapidly. The three routes in which the chemicals pass through capillary walls are the intercellular clefts between the endothelial cells, endothelial cell cytoplasm, and filtration pores of the fenestrated capillaries.