Descrição anatômica dos músculos do membro torácico da preguiça-comum (Bradypus variegatus) / Anatomical description of the forelimb muscles of the brown-throated sloth (Bradypus variegatus)

ABSTRACT

Background: Brown-throated sloths are mammals of the order Xenarthra, suborder Pilosa, family Bradypodidae. These folivorous and arboreal animals, which possess a peculiar type of arboreal quadrupedalism, move through the forest canopy by means of suspensory locomotion. On the ground, their extremely slow movements make them easy targets for road accidents, often leading to serious injury or even death. This paper describes the forelimb muscles of the brown-throated sloth (Bradypus variegatus), updating the literature on the subject to help veterinarians in clinical and surgical interventions on this species, and to provide data for comparative animal anatomy.Materials, Methods & Results: Five brown-throated sloths (Bradypus variegatus Schinz, 1825), two adults and three babies were dissected. The animals were donated by the Arruda Câmara Zoo and Botanical Park in João Pessoa, state of Paraíba, Brazil, where they were thawed and fixed in 10% formalin. The sloths’ forelimbs were dissected by lifting and folding over a skin flap to expose, identify and describe the underlying musculature. The dissection revealed the following muscles supraspinatus, infraspinatus, deltoideus, teres major, subscapularis, coracobrachialis, brachialis, biceps brachii, triceps brachii, anconeus epitrochlearis, dorsoepitrochlearis, brachioradialis, supinator, pronator teres, pronator quadratus, extensor carpi radialis, extensor carpi ulnaris, extensor carpi obliquus, flexor carpi radialis, flexor carpi ulnaris, extensor digitorum communis, extensor digitorum lateralis, palmaris longus, flexor digitorum superficialis, flexor digitorum profundus, extensor indicis longus second finger, extensor indicis brevis second finger, extensor digitorum third finger, abductor digitorum second finger, abductor digitorum third finger, palmaris brevis, and interosseous muscles.[...]