abnormal loop of Henle morphology abnormal loop of Henle ascending limb morphology 2011-10-13T09:44:50Z MA:0001676 MP:0011342 MPheno.ontology abnormal ansa nephroni ascending limb morphology abnormal ascending limb of Henle's loop morphology abnormal ascending limb of loop of Henle morphology abnormal ascending loop of Henle morphology any structural anomaly of the distal part of the loop of Henle that is impermeable to water and actively pumps sodium out of the filtrate to generate the hypertonic interstitium that drives countercurrent exchange; it consists of an initial very thin segment lined by simple squamous epithelium followed by a distal thick segment lined by simple cuboidal epithelium csmith