Osteoresistência em Chelonia mydas (linnaeus, 1758): avaliação morfológica, morfométrica e mecânica em ossos longos

Abstract

The objective of this work was to perform the anatomical description and biomechanical evaluation of the long bones of Chelonia mydas. For this, the bones were collected during necropsies. The first chapter evaluated the morphology and morphometry of long bones of C. mydas, which did not come from strandings on the southern coast of Espírito Santo. The bones emitted were: humerus, radius, ulna, femur, tibia and fibula. It was observed that the humerus is the longest bone. The tibia, fibula, radius and ulna bones have few morphological features when compared to the humerus and femur, being smaller and lighter. The radiological profile evaluated was within normal limits. The second chapter aimed to evaluate the axial compression test in C. mydas femurs. Ten green turtle femurs were used to perform the axial compression test. The types of fractures found were A3 (60%) and Salter-Harris (40%). The morphological characteristics of the femur such as weight and circumference of the diaphysis did not influence the parameters of rupture, elasticity and total strength. Histology revealed low activity of osteocytes, osteoblasts and osteoblasts. Predominant type 2 and 3 collagens. Deflection fracture mechanism and normal Ca patterns: P. The third chapter consists of three-point flexion tests on humeral bones and femurs performance of C. mydas. Thirty-three humeri and 28 left femurs of C. mydas were used to perform the three-point flexion test on a universal machine. The morphological characteristics of circumference and diaphysis area and to total length, were correlated with modulus of elasticity, modulus of rupture and maximum force. Histology showed low cellular activity of osteocytes, osteoclasts and osteoblasts. The predominant types of osteons were 2 and 3 and longitudinal fibers. The deflection fracture mechanism was greater in both the cortical and medullary regions. The Ca and P relationship had no influence on the modulus of elasticity values. The values ​​given from the mechanical test were mostly influenced by mineral activity in the humerus, while the femur by the circumference of the diaphysis.