Sentence:  Each tight junction is followed by an adhering <WSD>zonule</WSD> extending between arrows "2" and "3" and, farther away, by a desmosome marked "D". A condensation of finely fibrillar material occurs mainly along the adhering <WSD>zonules</WSD> on each side of the bile capillary. 
Meaning of the word marked with <WSD> tags:  A little zone, or girdle; a zonula.