79 Summer & Autumn 2021, Volume 18, Number 2 Research Paper: Morphology of the Great Cardiac Vessels in Egyptian Fruit Bat ( Rousettus aegyptiacus ) Younes Kamali 1* , Farangis Ghasemi 2 1. Department of Basic Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran. 2. Department of Biology, Jahrom Branch, Islamic Azad University, Jahrom, Iran. * Corresponding Author: Younes Kamali, PhD. Address: Department of Basic Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran. Tel: +98 (915) 7878617 E-mail: youneskml@shirazu.ac.ir A B S T R A C T Keywords: Anatomy, Egyptian fruit bat, Large vessels, Heart Introduction: The purpose of this sudy was to describe the anatomic appearance of great cardiac vessels in the Egyptian fruit bat (Rousettus aegyptiacus) as a common bat living in the southern region of Iran. Methods: Five Egyptian fruit bats with a Mean±SD body mass index (BMI) of 123.04±0.08 g were selected and sudied. Results: The aortic arch (transverse arch) cranial to the heart gives rise to the right and left brachiocephalic (innominate) arteries, each of which immediately divides into common carotid and subclavian arteries. The aortic arch continues caudally on the dorsal side of the heart, inclines to the left of the median plane as the dorsal aorta. The ligamentum arteriosum connecting the dorsal aorta to the pulmonary trunk is seen a few millimeters caudal to the origin of the left brachiocephalic artery. The arrangement of the great veins, including two anterior venae cavae, resembles that found in birds rather than mammals. A left azygos vein entered dorsally to join the left anterior vena cava. The opening of the right anterior vena cava is in the dorsal part of the right atrium; the opening of the left anterior vena cava, similar to the coronary sinus, is at the caudal part of the right atrium. The poserior vena cava opens into the right atrium dorsal and cranial to the entrance of the left anterior vena cava. Conclusion: The evolution in the morphology mentioned above is in accordance with the fight requirements of bats. Article info: Received: 03 Mar 2021 Accepted: 23 May 2021 Available Online: 01 Jul 2021 Citation Kamali Y, Ghasemi F. Morphology of the Great Cardiac Vessels in Egyptian Fruit Bat (Rousettus aegyptiacus). Anatomical Sciences. 2021; 18(2):79-84. Use your device to scan and read the artcle online 1. Introduction n mammals, several great vessels are di- rectly connected to the heart, including the ascending aorta, pulmonary trunk, pulmonary veins, the superior vena cava, and the inferior vena cava. The ascend- ing aorta arises from the left ventricle and curves back over the heart to form the aortic arch. It becomes the descend- ing thoracic aorta as it continues downwards through the thorax. The number of branches that arise directly from the aortic arch difers from one to four, depending on mammal species [1]. Two large veins, namely the cranial vena cava and caudal vena cava, drain deoxygenated blood into the right atrium of the heart from the upper and lower body, respectively. The cranial vena cava is formed by merging two brachiocephalic (innominate) veins at the thoracic inlet I