spleen white pulp morphology trait spleen central arteriole morphology trait Any measurable or observable characteristic related to the shape, structure, color, or pattern of the blood vessel surrounded by the periarteriolar lymphoid sheath that connects the trabecular artery to the trabecular vein. CA morphology trait Trait.ontology VT:0002361 follicular arteriole morphology trait splenic central arteriole morphology trait arteriole morphology trait