Branching and distribution of the phrenic nerves in the diaphragm of Brazilian Northeast asses (Asinus asinus)

Abstract

The results obtained from the study of 30 diaphragms of adult asses {Asinus asinus), extracted from 15 male and 15 female animals from the Brazilian Northeastern region, allowed us to reach the following conclusions: 1) The phrenic nerves more frequently result in a lumbocostal trunk and sternal branch, either right (76.7%) or left (53.3%); symmetric disposition was registered in some pieces (43.3%); 2) The lumbar branches are destined to the corresponding crura (pars lumbalis); the right branches give small branches to the medial left crus (3.3%), to the right dorsal foliole (6.7%) and to the left dorsal foliole (3.3%), and the left
ones also give small branches to the medial right crus (3.3%) to the left dorsal foliole (13.3%) and to the ventral foliole (6.7%);
3) The costal branches are distributed to the dorsal region of the pars costalis of each respective side, either right or left, to the right side of the ventral region (3.3%) and to the right dorsal foliole (3.3%), and the left one to the left dorsal foliole (10.0%); 4) The sternal branches are destined to the pars sternalis and ventral region of the pars costalis at the same side; at the right side, they give small branches to the vena cava caudalis (3.3%), or to the ventral foliole (3.3%).