Anatomy of Abdominal Aorta in Tatu Peba (Euphractus sexcinctus-Linnaeus, 1758): A Descriptive and Comparative Study

Tatu Peba is an animal from Euphractus genus whose anatomy and/or systemic description are little studied, a fundamental understanding of biological system knowledge of this animal. Thus, this work aimed perform an anatomical description of abdominal aorta and Tatu Peba branches through a comparative study using 2 male and 2 female specimens. In this sense, the present work showed unprecedentedly discovery about this animal as the first major branch of abdominal aorta is celiac trunk and the second branch is a. Mesenteric cranial. From ventrolateral face, a. Phrenic caudal, by ventral small face Aa. Accessory Mesenteric and five pairs of Aa. Lombares. Medium distance, between Celiac Trunk and Aa. External Iliacs, born Renal arteries. A. Caudal Mesenteric emerges ventrally to caudal part of large intestine. In the final part of aorta, Aa. External Iliacs borns ventrolaterally and caudally projected. After Aa. External Iliacs origin, the aorta undergoes a drastic reduction of caliber and forms a short trunk that divides into terminal branches of aorta: right internal iliac, Left Internal Iliac and a. Median sinsacral in sagittal plane which emits an a. Lateral to each side, following three caudally. In view of these findings, the present study showed that abdominal aorta of Tatu Peba presents smaller number of branches bought from other mammals and contributes to anatomical description and understanding of important blood vessels in this animal biological system. Keywords— Anatomy, Euphractus sexcinctus, Brazilian fauna, Cerrado biome and Wild animals.


INTRODUCTION
There are 21 species of armad illos described, which 11 are fro m Brazilian fauna [1]. Euphractus sexcinctus (Tatu Peba) specie is the only of Euphractus genus and belongs Daypodidae family inserted in Cingulata order and Xenarthra superorder [2]. This animal is regionally known as Tatu Peba or Tatu Peludo [3] and the carapace has a variable co loration fro m yellowishbrown to light brown, formed by 6 to 8 mov ing bands. The head is conical, the tail long and protected by horny rings and it whit ish and long hairs [4], giv ing rise to the popular name of this species. It is widely distributed in South America, including Brazil where it habits several biomes such as Amazon, Caatinga, Cerrado, Pantanal, Mata Atlântica and Campos [5], savannas, dry forests, semi-deciduous forests and forest edges [6,7].
This specie is frequently victim of road crashes [11] and although its meat has a strong and singular flavor, so much appreciated and constantly hunted [12]. Despite tramp ling deaths , hunting and disturbances caused by anthropic activities, this species is not threatened with extinction [13].
Xenarthra superorder presents some anatomical peculiarities, such as additional joints between the caudal vertebrae, allowing erect posture in s ome situations. Some authors reports the presence of caudal cavae pair of veins, undifferentiated external genitalia, low metabolism and body temperature ranging fro m 32.7 ° C to 35.5 ° C [14,15].
The anatomical, topography and systemic descriptions of any specie are fundamental for biological system knowledge, as well its importance in clinical veterinary practice. However, even the importance of anatomy of wild animals for the eco-sustainability in biome; as well the value of species in the ecosystem, the anatomy of Tatu Peba is little studied. Considering the importance of circulatory system in animal anatomy as an internal mean of transport and an important access route in clinic, where provides data in clinical intervention or preservation programs, the objective of this work was investigate and describe the anatomy of Abdominal Aorta and its branches in Tatu Peba as a literary subsidy for different areas of knowledge.

II.
MATERIAL AND METHODS The present paper is a descriptive anatomical study with two male and two female specimens of Tatu Peba (Euphractus sexcinctus -Linnaeus, 1758), obtained fro m accidental death on the roadsides of Brazilian Southeast of Goiás, under authorization of SISBIO nº 37072-2. Considering the descriptive approach of this work, statistical analysis is not necessary. All p rocedures were conducted in accordance with ethical principles and were approved by the Institutional Ethics in Research Co mmittee at the Federal University of Uberlândia (CEUA/UFU nº 067/12).
The study was made in the research laboratory of human and comparat ive anatomy fro m the Federal University of Goiás -RC, as previously described by our group [16], were the arterial system was dissected and inject with Latex Art Glue, co lored with red pig ment Wandalar, through the carotid artery. Subsequently was made a fixat ion with aqueous 10 % formaldehyde solution to conservation. The preparation of anato mical p ieces was performed under consecrated techniques in Macroscopic Anatomy. For this, after trichotomy of anterolateral abdomen region, an incision was made along Linea Alba, fro m xiphoid process to cranial ext remity of the pubic symphysis. Other incisions were performed laterally, accompanying costal border of each side and inguinal region appro ximated of inguinal ligament. The abdominal wall was laterally open to visceral exposure, then all abdominal part and digestive system secluded, exposing the dorsal wall of abdomen. With an anato mical forceps, the adipose tissue and other tissues were removed to expose abdominal aorta artery and its branches. A stereomicroscope MOTIC SMZ -168, with magnificat ion of 10X was used to dissection procedure.
The Nikon® D7000 18-105 d igital camera was used to photographical documentation and description nomenclature adopted is the standard of No mina Anatomica Veterinaria (2012) [17], elaborated by the International Co mmittee on Veterinary Gross Anatomical Nomenclature.

III. RESULTS
The diaphragmat ic p illars of Tatu Peba (Euphractus sexcinctus) are long and protrude caudally to level of iliopsoas muscles origin. The aortic gap comprises an space delimited by diaphragmatic pillars through Aorta enters abdominal cavity appro ximate fro m level of L1 and runs along dorsal wall of abdomen, slightly to left of vertebral bodies. The first major branch of abdominal aorta is the Celiac Trunk, being the largest branch of abdominal aorta and characterized as unpaired vessel, short and large caliber vessel, originating in ventral aspect of Aorta at level L2 between the pillars of diaphragm. Soon after its origin, Celiac Trunk trifurcases in Common Hepatic a. sideways to right, Left Gastric a. laterally to left and posterior to Lienal.
The second branch of abdominal aorta is Cranial Mesenteric a. with unpaired characteristic and large caliber vessel, originating fro m ventral face at level L3 near Celiac Trunk origin directed to intestines. Near Cranial Mesenteric a. origin borns Left Caudal Phrenic Aa. as a unique vessel by left ventrolateral face at L3 level, which is d irected to left diaphrag matic pillar and already on diaphragm surface divided into right and left branches, there being no Caudal Phrenic a.. Four small accessory mesenteric arteries were identified, one arising from Left Gastric a. and the others from aorta.
Five pairs of Lumbar Arteries are present in Tatu Peba, wh ich arise fro m dorsal surface of Abdominal Aorta. These arteries are arranged equidistantly fro m diaphragmatic pillars to final bifurcation of aorta, the fifth pair being already located within pelvis.  The average distance between Celiac Trunk and External Iliacs Aa. at L3-L4 level, Renal Arteries born laterally, the right being relat ively longer than left. In variable nu mbers, adrenal arteries are branches of Renal Arteries. Then, caudally at L5 Caudal Mesenteric a. emerges ventrally to caudal part of large intestine. In final part of aorta (abdominopelvic transition), the External Iliacs Aa. borns ventrolaterally and caudally projected.
After External Iliacs Aa. origin, aorta undergoes a drastic reduction of caliber forming a short trunk and div ides into terminal branches of aorta: the Right Internal Iliac, Left Internal Iliac and in sagittal plane Median Sinsacral a. that borns dorsally. Aa. Internal Iliacs supply intra-pelvic structures and provide Gonadais Arteries, while Median Sinsacral emits an Lateral Sinsacral a. to each side, following three caudally.  //dx.doi.org/10.22161/ijaers.6.3.27  ISSN: 2349-6495(P) | 2456-1908(O) www.ijaers.com Page | 216 The literature have little data regarding Accessory Mesenteric Arteries, but in Tatu Peba four of them can be counted with variable origins and arise fro m Left Gastric a. or direct ly fro m Aorta. Five pairs of Lumbar Arteries are present in Tatu Peba, whose origins occur on dorsal aspect of aorta and equidistant from each other, fro m diaphrag m to sinsacral cavity. In Bicho Preguiça it can be identified between t wo to ten pairs of Lumbars Aa, with higher nu mber in female specimens [20]. Six pairs can be observed in Nutria [25] and Jaguatirica [24], whereas in New Zealand Rabbits seven pairs are observed and three pairs in Tamandua Mirim [22,21].
In Tatu Gambá [49] and Nutria [25] is described a formation of a co mmon trunk between Internal and External Iliac Aa., at the same level of Internal Iliac Aa. that born fro m Aorta, dorsally to Median Sinsacral a. and paired by two Lateral Sinsacral Aa., fo llo wing then in direction to the tail.

V.
CONCLUSION The present study demonstrated by unprecedentedly relates that Abdominal Aorta of Tatu Peba (Euphractus sexcinctus) presents smaller number of branches, different fro m other mammals. When compared to other components of Xenarthras Superorder and great similarity with regard to number and vascular distribution. Thus, this work contributes to anatomical description and understanding of an important blood vessel in Tatu Peba biological system.

VI.
COLABORATORS Thalles Anthony Duarte Oliveira, Kad ija Mohamed Santee, Tarley Santos Oliveira, Vinícius Gonçalves Fontoura and Bruna Silva Lopes were responsible for acquisition, analysis and interpretation of data. Thiago Sardinha de Oliveira, Roseâme ly Angélica de Carvalho Barros and Zenon Silva were responsible for concept, design and preparation of manuscript. All authors read and approved the final version of manuscript.

CONFLIT OF INTESREST
The authors declare no conflicts of interest associated with this manuscript.