Arterio-venous anastomoses in the human skin and their role in temperature control.
Level 5 - mechanism / opinion, no new human data
Narrative review and mechanism-based physiological description without original experimental data
PubMed 27227081 · doi:10.1080/23328940.2015.1088502
What was done
This paper describes the anatomical structure, sympathetic innervation, and physiological mechanisms of arterio-venous anastomoses (AVAs) in human glabrous skin and their role in thermal control across the thermoneutral zone.
What was found
The abstract reports that the human thermoneutral zone for a naked resting subject is approximately 26°C to 36°C (lower when active and clothed). AVAs are closed near the cold end of this range and fully open near the warm end. Small limb veins constrict in cooler conditions, directing blood through deep veins via a countercurrent cooling mechanism, and relax in warmer conditions, directing blood through superficial limb plexuses to maximize surface heat loss. No quantitative experimental trial data, error margins, or statistical comparisons are provided in the abstract.
Why it matters
It summarizes how specialized vascular shunts in human hands and feet actively adjust heat conservation versus heat dissipation across baseline environmental temperatures.
Limits
The abstract presents a narrative, mechanism-based overview rather than empirical study results. No sample size, population details, comparator groups, or experimental measurements are reported.
Cited by
- supports The palms of the hands are thermoregulators for the human body.