Task: Class Definition Understanding (ontology: Earth_Environment/EnvironmentOntology)

Which of the following definitions best describes 'epithelial tube'?

A. An epithelium consisting of cuboidal epithelial cells.
B. Epithelium that derives from the endoderm. Examples: urothelium, transitional epithelium of ureter, epithelium of prostatic gland.[FMA].
C. An epithelial tube that will give rise to the mature heart.
D. Epithelial tubes transport gases, liquids and cells from one site to another and form the basic structure of many organs and tissues, with tube shape and organization varying from the single-celled excretory organ in Caenorhabditis elegans to the branching trees of the mammalian kidney and insect tracheal system.

Answer: Epithelial tubes transport gases, liquids and cells from one site to another and form the basic structure of many organs and tissues, with tube shape and organization varying from the single-celled excretory organ in Caenorhabditis elegans to the branching trees of the mammalian kidney and insect tracheal system.