basal body:

a centriole from which an axoneme arises.

binary fission:

a mode of reproduction of unicellular organisms in which internal organelles are duplicated and then cytokinesis takes place.

bladder larva:

in Cestoda, a larval form in which one or more scoleces develop in a fluid-filled cyst.

blood loss:

significant loss of blood as a result of a disease process, either through hemorrhage or ingestion.

bothridium:

a muscular projection of the side of the scolex of some tapeworms.

bothrium:

a muscular longitudinal groove on the scolex of some tapeworms.

brood capsule:

a capsule developing within a hydatid cyst, lined with germinal epithelium and capable of asexual production of protoscoleces.

buccal capsule:

the lining of the oral cavity.

bulla:

a non-living structure used for attachment.

bursa:

an external male copulatory appendage, used to grip the female during mating.