Density of arteriovenous anastomoses in some skin areas of the domestic fowl (Gallus domesticus).

The vascularity and the density of arteriovenous anastomoses (AVAs) were studied in the skin of the domestic fowl by using vascular injections and histological sections. The density of AVAs and associated blood vessels were low in the wattles and in the thoracic skin (five to 23 AVAs per cm2 and five to 14 AVAs per cm2, respectively), whereas the eyelids were highly vascular and contained many AVAs (170-172 AVAs per cm2). It is suggested that the blood vessels in the eyelids are important in the temperature regulation of the eye and that AVAs in the thoracic skin may contribute to the control of blood flow through the brood patch.