Theampulla oftheductus deferens inman: morphological andultrastructural aspects

Inorder tocompare thehistology oftheampulla oftheductus deferens withthatoftheother segments of theductinman,theseminal vesicle andtheadjacent 13-15 cmoftheductus deferens wereobtained during cystectomy from15adult men,andwereprocessed forlight andelectron microscopy. Eachductus deferens specimen wasdivided into3segments: segment A orinitial segment (the mostproximal tothetestis) showing asmoothouter surface and,onsection, auniform lumenandabsence ofmucosal invaginations; segment B(1.5-4 cm)showing asmooth outersurface and,onsection, small cavities inthemucosa; and segment C orampulla (3-4 cm),which waseasily recognisable because ofthecerebriform pattern onits outer surface. Segment A showed theusual histological pattern reported instudies ofthehumanductus deferens. Segment Bconsisted ofmucosa, muscularis mucosae, submucosa, muscular coatandadventitia. Theepithelial lining formed multiple branched invaginations inthelamina propria andsubmucosa giving rise toglandular structures. Thelumenoftheductandtheglands werelined bythesamecell types: (1) basal cells; (2)mitochondrion-rich cells; and(3)columnar cells withtheultrastructural features of glycoprotein-secreting cells. Thelatter cells could beclassified into3subtypes suggesting different stages of development: (a)withabundant mitochondria; (b)withabundant roughendoplasmic reticulum; and(c) withabundant secretory granules. Segment C ortheampulla showedthesamehistology assegment B except forthepresence ofmanydiverticula intheampulla. Spermatozoa wereinfrequent inall3segments of theductus deferens examined. Thelumenoftheductus deferens wassignificantly larger andthemuscular coatthinner insegments BandC thaninsegment A.Thesurface areapercross-sectioned ductoccupied by theglands anddiverticula wasgreater insegment C thaninsegment B.Thepresent findings suggest that rather thanbeing aspermreservoir asinother mammals, thehumanampulla isasecretory structure which begins inthepreceding segment.