Morphological Characterization of Diaphragm in Common Squirrel Monkey (Saimiri sciureus)

Abstract

The wall of the diaphragm can be affected by congenital or acquired alterations which allow the passage of viscera between the abdominal and chest cavities, allowing the formation of a diaphragmatic hernia. We characterized morphology and performed biometrics of the diaphragm in the common squirrel monkey Saimiri sciureus. After fixation, muscle fragments were collected and processed for optical microscopy. In this species the diaphragm muscle is attached to the lung by phrenopericardial ligament. It is also connected to the liver via the coronary and falciform ligaments. The muscle is composed of three segments in total: 1) sternal; 2) costal, and 3) a segment consisting of right and left diaphragmatic pillars. The anatomical structures analyzed were similar to those reported for other mammals. Histological analysis revealed stable, organized muscle fibers with alternation of light and dark streaks, indicating transverse striation.

Participation of the Intercostal Nerves to the Innervation of the Diaphragm Muscle in Cavia porcellus

“…[6][7][8][9][10][11][12][13] On the other hand, our findings are in agreement with other studies that pointed out the contribution of the intercostal nerves to the innervation of the diaphragm. 4,5,[14][15][16][17][18][19] We observed the innervation of the diaphragm by the intercostal nerves 6 to 12, mainly by the 8 th nerve. Rosenblueth et al (1961), 4 even if they observed the participation of the intercostal nerves 4 to 10, observed that the major intercostal nerve acting in the innervation of the diaphragm was the 8 th nerve.…”

“…[6][7][8][9][10][11][12][13] Even the same, in some species, there is a participation also from branches derived from the intercostal nerves. 5,[14][15][16][17][18][19] There are 12 pairs of intercostal nerves. They derive from the ventral branches of the thoracic nerves, do not form plexus and distribute to the walls of the thorax and the abdomen.…”