Table S3. Blood supply to the eye and orbit of the adult alpaca, Vicugna pacos from Cranial arterial patterns of the alpaca (Camelidae: Vicugna pacos)

2017-03-09T15:40:57Z (GMT) by Haley D. O'Brien
Artiodactyl cranial arterial patterns deviate significantly from the standard mammalian pattern, most notably in the possession of a structure called the carotid rete (CR)––a subdural arterial meshwork that is housed within the cavernous venous sinus, replacing the internal carotid artery (ICA). This relationship between the CR and the cavernous sinus facilitates a suite of unique physiologies, including selective brain cooling. The CR has been studied in a number of artiodactyls; however, only a single study to date documents a subset of the cranial arteries of New World camelids (llamas, alpacas, vicugñas and guanacoes). Within New World camelids, cranial arterial descriptions can provide important background for understanding physiological adaptations to life in high altitudes, such as oxygen metabolism in the brain. This study is the first complete description of the cranial arteries of a New World camelid species, the alpaca (Vicugna pacos), and the first description of near-parturition cranial arterial morphology within New World camelids. This study finds that the carotid arterial system is conserved between developmental stages in the alpaca, and differs significantly from the pattern emphasized in other long-necked ruminant artiodactyls in that a patent, homologous ICA persists through the animal's life.