Mirror of Research in Veterinary Sciences and Animals (Aug 2016)
Anatomical and histological studies of esophagus of one-humped camel (Camelus dromedarius)
Abstract
This study was designed to describe the anatomical and histological features of the normal esophagus in one- humped dromedary camel (Camelus dromedarius). Twelve adult male camels were used for this study. Anatomical features were described and samples were collected from 8 animals. Samples were kept in 10% neutral buffered formalin and processed with routine histological procedures. The present study revealed that the length of the esophagus of camel was 148±2.3 cm. The esophageal outer diameter began in the cervical portion at 2.6 ±0.5 cm and gradually enlarged to 4±0.2 cm in thoracic inlet. In the cranial part the esophagus of camel lied dorsally to the cricoids cartilage of the larynx and trachea. However, the cervical region deviates to the left of the trachea and maintains this relation until it reaches to the end of cervical region, where it again slopes to the dorsal region of the trachea. Later on, the esophagus continues caudally in thoracic cavity and passes through the esophageal hiatus of the diaphragm and after a short abdominal part it joins to the cardiac region of the stomach. The histological study showed that the esophagus of camel composed from many layers. It is arranged from internal to external in order: the mucosal layer consist of keratinized stratified squamous epithelium, the lamina propria (contain a relatively dense connective tissue with amount of elastic fibers), the Muscularis (consist from two layer of smooth muscle bundles that are relatively large). The sub mucosal glands abundant throughout the esophagus (this gland were less numerous towards the caudal end of the esophagus), while the number of lobules of sub-mucosal glands found in each region of the esophagus ranged from 42 in the cranial cervical region to 31 in the middle thoracic region. The tunica muscularis of the esophagus are stratified muscle and it is occurred in two general layers inner circular muscularis layer and outer longitudinal muscularis layer.
