Development of arteriovenous anastomoses in the skin of the chicken and the influence of environmental temperature.
Posthatching differentiation of arteriovenous anastomoses (AVAs) and the effect of heat exposure (38 degrees C) and cold acclimation (2-3 degrees C) on AVA density were studied in naked skin areas (eyelids, comb, wattles) of chickens. The AVAs were identifiable in the newly hatched chick, but they were extremely simple. The number of cell layers in the wall of the AVAs increased from two at hatching to four to five in the 5-month-old chickens. The density of the AVAs increased significantly during posthatching maturation. Cold acclimation of the chickens increased the density of AVAs by a factor of 2.1-3.2. Daily heat exposure also increased the density of AVAs significantly in the eyelids but had no effect in the other skin areas. Heat and cold had only minor effect on the vascularity of the skin; the only significant change recorded was a slight increase in the number of blood vessels in the wattles of the cold-acclimated chickens.
Midtgård
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Institute of Cell Biology and Anatomy, University of Copenhagen, Denmark.
D000818:Animals; D001163:Arteriovenous Anastomosis / Q000473:pathology*; D003129:Comb and Wattles / Q000098:blood supply / Q000473:pathology; D005143:Eyelids / Q000098:blood supply / Q000473:pathology; D005260:Female; D008297:Male; D012867:Skin / Q000098:blood supply / Q000473:pathology*; D013696:Temperature