MORPHOLOGIC BASES OF FOREIGN BODY ASPIRATION IN MAN

Abstract

It has been stated that in some animals foreign bodies are found in the esophagus but not in the tracheo-bronchial tree. In Man foreign bodies in the lower airway are of frequent occurrence. This difference between animals and Man prompted the author to investigate the comparative morphology and the basic principles involved.
In this study domestic animals as horse, dog, ox, pig and sheep were employed in comparison with Man. The results obtained are as follows.
In the animals studied, an elongated soft palate and a big epiglottis are in close contact with each other. In some, these two structures are overlapped so that the normal air tract is shut off from the oral cavity. The palate has lateral palatine fold which also assists in the exclusion of the mouth from nasal passages. In addition, the air and food highways in the animals do not cross at the same plane. These animals, therefore, can with impunity breathe and swallow at the same time.
In Man it is not so. There is a gap of several centimeters between the soft palate and the epiglottis, the former being short and degenerated with uvula as its relic. Thus respiration and deglutition can not be carried out synchronously as during the act of swallowing the breathing mechanism has to cease or vice versa. Moreover, the air and food highways intersect at the same plane in the pharynx. In children, particularly, bronchial foreign body incidence frequently occurs resulting from underdeveloped epicritic sense in the sequential mechanism of respiration and deglutition.
The author discusses other morphologic and functional factors which are attributable to the foreign body aspiration.