| The innermost layer adjacent to the lumen was occasionally difficult to distinguish. |
| The tumors located centrally were polypoid, protruding into the lumen of the bronchus and narrowing the lumen. |
| The lower esophageal sphincter is tonically contracted at rest to seal the lumen in a rosette at the esophagogastric junction. |
| The lumen or cell chain is not always clearly visible within all filaments, especially within densely granulated sheaths. |
| Four tunnels off the lumen of the proventriculus of the carpenter bee, Xylocopa virginica virginica, have been discovered. |
| This contraction wrinkles the thick mucosa at this level so that the fully occluded lumen takes on a stellate configuration. |
