Histological Investigation of the Lung in Adult Male Guinea Pig

Abstract

The study was done on six adult guinea pigs weighing 300-400g and 180 days old. These healthy adult male pigs (Cavia porcellus) were obtained from the Drug Control Center in Baghdad, Iraq. Then, the animals were euthanized by using chloroform anesthesia to examine the histological features of the lungs in adult guinea pigs. The animals were prepared for anatomy by opening the chest with a scalpel after the animal was anesthetized. From the chest cavity, the lung was removed, and four lobes of the right lung, three lobes of the left lung, and two lungs in the chest cavity were revealed, around the middle body and heart. Histological analysis in the current study showed that the lung parenchyma contained alveoli, air sacs, and air ducts, in addition to the presence of bronchioles that were devoid of cartilage and replaced by smooth muscle fibers. The wall of the lung's alveoli was found lined with alveolar (squamous) cells Type I, which are involved in blood-blood gas exchange, and alveolar (squamous) cells Type II, which are involved in the secretion of a lipid-binding substance to prevent collapse. The interstitial tissue between the alveoli is composed of collagen and elastic fibers and contains macrophages, white blood cells, and blood vessels. The collagen fibers are essential for supporting the framework of the lung, while the elastic fibers assist in the elasticity of the lung during breathing.