All bilaterians have a gastrointestinal tract, also called a gut or an alimentary canal. "Streptococcus dysgalactiae subspecies equisimilis" is a commensal in human alimentary tract and genital tract. Esophageal atresia is a congenital medical condition (birth defect) that affects the alimentary tract. Rectal foreign bodies are a subgroup of foreign bodies in the alimentary tract. In addition to the alimentary canal, insects also have paired salivary glands and salivary reservoirs. The sympathetic nervous system consists of nerve plexuses in the epidermis and alimentary canal. Galen describes symptoms of the alimentary tract via a patient's diarrhea and stools. Malpighian tubules are slender tubes normally found in the posterior regions of arthropod alimentary canals. An increase in pylorostenosis or alimentary tract atresia was seen. The alimentary canal directs food unidirectionally from the mouth to the anus. These stolen nematocysts, called kleptocnidae, wander through the alimentary tract without harming the nudibranch. The reticulum is the second chamber in the alimentary canal of a ruminant animal. The hindgut (or epigaster) is the posterior (caudal) part of the alimentary canal. Other effects included&colon; deformed eyes, hearts, alimentary, and urinary tracts, and blindness and deafness. Acanthocephalans lack a mouth or alimentary canal.