Abstract
Objective: Papillary loops in dermal papillae are believed to facilitate oxygen delivery to the germinal layer in the epidermis. The study aims to simulate the distribution of the oxygen partial pressure, pO2, in superficial layers of skin and to quantify oxygen supply from different sources.
Methods: A theoretical model that considered heterogeneity in tissue properties was developed based on the anatomical arrangement of the upper skin. Distribution of pO2 in tissues and in blood was solved numerically. Effects of the blood flow rate and the skin surface condition were investigated.
Results: Under normal blood flow rate and skin surface conditions, approximately one-quarter of the oxygen consumed in the upper skin came from papillary loops. Subpapillary plexus was the main supplier, which accounted for more than 60% of the total oxygen supply. Oxygen diffusion into the skin from the air was restricted to superficial regions of the germinal layer and accounted for approximately 10% of the total oxygen uptake.
Conclusions: Papillary loops in dermal papillae facilitate oxygen delivery to the germinal layer from the circulation. The flow rate in papillary loops affects pO2 distribution in dermal papillae. In the epidermis, however, pO2 is strongly affected by skin surface conditions.
This work was supported by the Wellcome Trust (051015).