Anatomia descritiva aplicada à cinesiologia e biomecânica básica dos músculos da cintura peitoral, estilopódio e zeugopódio do jacaré do papo amarelo

Abstract

Descriptive anatomy applied to the kinesiology and basic biomechanics of the pectoral girdle, stylopodium and zeugopodium muscles of broad snouted caiman

MUSCULAR ANATOMY OF THE PECTORAL AND FORELIMB OF Caiman crocodilus crocodilus (LINNAEUS, 1758) (CROCODYLIA: ALLIGATORIDAE)

“…According to Diogo et al, (21) the different segmentations of the pectoralis between reptiles and Archosauria indicated that this configuration was acquired independently in evolution. According to Romão et al, (23) the pectoralis in C. latirostris showed greater longitudinal distance from A. mississippiensis, C. siamensis, C. actus, O. tetraspis, and G. gangeticus, (24) offering better possibility of mobility. The supracoraoideus complex consists of three muscles in A. mississippiensis, C. siamensis, C. actus, O. tetraspis, G. gangeticus, (24) and C. latirostris.…”

“…Crocodilians, however, presents segmentation on superficial and deep head. (20) Romão et al (23) reported the existence of a cranial parallel fiber segment and other caudal oblique fiber segment. This was also reported with three heads, (22,24) an inconstant deep head, superimposed by the flow head that may occur.…”

“…In all described crocodilians, the segments converged into one tendon that inserted into the deltopectoral crest of the humerus. (19,(22)(23)(24) Meers (24) pointed out, in the Crocodilus actus, the pectoralis had a unique origin fixed in the third gastralia. According to Diogo et al, (21) the different segmentations of the pectoralis between reptiles and Archosauria indicated that this configuration was acquired independently in evolution.…”

“…The supracoraoideus complex consists of three muscles in A. mississippiensis, C. siamensis, C. actus, O. tetraspis, G. gangeticus, (24) and C. latirostris. (23) For C. crocodilus crocodilus, the intermediate head is not defined as showed in reports for other crocodilians. Meers (24) described a common tendon of insertion for intermediate and short heads, which can be difficult to distinguish in the bellies of C. crocodilus crocodilus.…”

“…An alleged mechanical advantage was observed among C. latirostris, A. mississippiensis, C. siamensis, C. actus, O. tetraspis, and G. gangeticus (24) for the supracoraoideus complex, originating in the lateral humerus in proximal aspect. (23) Deep to the pectoralis muscle there was a pair of costocoracoideus (superficialis and profundus) it assisted in retraction of the coracoid, although there was no significant action to provide stability to this segment. In A. mississippiensis, C. siamensis, C. actus, O. tetraspis, G. gangeticus, (24) and C. crocodilus crocodilus, its origin occurs in the costal margin and insertion into the caudal border of the coracoid (superficialis) and craniolateral margin of sternal plate and ventral surface of the coracoid (profundus) (Fig 1).…”