Conceitos básicos sobre circulação sanguínea de Gallus gallus

Abstract

The circulatory system is undoubtedly one of the most important systems for the survival of the domestic chicken. To ensure proper breeding, it is essential to understand the location, organization, and particularities of this system in these animals. The work developed by the academics of the extension project "Knowing, respecting and producing birds: didactic and alternative models in the teaching and learning process", linked to the discipline Anatomy of Domestic Animals (BA065) of the Zootechnics course at the Federal University of Paraná (UFPR), aimed to demonstrate morphologically and topographically the structure of the circulatory system of the domestic chicken (Gallus gallus domesticus), highlighting its divisions and specific characteristics. As in mammals, the circulatory system of birds is divided into two major circulations: (1) Systemic circulation ("large circulation"), in which arterial blood, rich in oxygen, leaves the left ventricle and is distributed throughout the body through the arteries. After releasing oxygen and nutrients to the tissues, it returns to the heart, emptying into the right atrium; (2) Pulmonary circulation, characterized by transporting venous blood from the vena cava (cranial and caudal) of the right ventricle to the lungs, where gas exchange (hematosis) occurs. After being oxygenated, it returns to the heart through the pulmonary veins, reaching the left atrium. Although the blood transport system is very similar to mammals, an important peculiarity in the blood circulation of birds is the presence of the renal portal system. In this system, blood from the pelvic limbs and dorsal region (femoral and sciatic veins) passes through the kidneys first before returning to the heart. This characteristic helps in water conservation and regulation of renal filtration. For this reason, it is important not to apply medications to the pelvic limbs of birds, since these substances can be filtered by the kidneys before exerting the desired effect on the organism.