- papilla:
- an external projection of the cuticle or tegument.
- parabasal body:
- a Golgi body connected by a filament to a kinetosome.
- parasite:
- an organism studied by parasitologists.
- parasitemia:
- a measure of the number of parasites present in the peripheral blood.
- paratenic host:
- a host in which a parasite survives, and can be transmitted to another
host, but does not develop.
- parenchyma:
- cellular matrix within which the internal organs of Platyhelminthes are
contained.
- parthenogenetic:
- development of an unfertilized egg into a new individual.
- pedipalp:
- lateral jointed oral appendages on Arachnida.
- pedunculate:
- occurring on a stalk.
- pellicle:
- the thick, often sculptured external coat of many Protozoa.
- penis:
- organ of the male reproductive system used to introduce spermatozoa into
the female reproductive tract.
- pharynx:
- muscular pumping organ at posterior of esophagus.
- phasmid:
- a lateral sensory pit on the tail of some Nematoda.
- phyllidea:
- leaf-like lateral projections on the scolex of some Cestoda.
- plasma membrane:
- the unit membrane enclosing the cytoplasm of a cell.
- plerocercoid:
- last larval form found in the second intermediate host of many Cestoda with
aquatic life cycles.
- pleural plate:
- chitinized regions on the sides of the abdomen of Insecta.
- polar:
- located at one or both ends.
- polyzoic:
- possessing multiple sets of reproductive organs.
- poral:
- located on the same side as the genital pore.
- presoma:
- the proboscis, neck and supporting structures and organs in Acanthocephala.
- proboscis:
- a protrusible, armed attachment organ in Acanthocephala.
- proboscis sheath/receptacle:
- a muscular sac ant the anterior end of Acanthocephala into which the
proboscis may be withdrawn.
- procercoid:
- larval form found in the first intermediate host of many Cestoda with
aquatic life cycles.
- proglottid:
- a single segment of strobila of Cestoda.
- prohaptor:
- anterior attachment organ of Monogenea.
- progenesis:
- precocious sexual development of an organism that is still morphologically
at a juvenile stage.
- promastigote:
- a form of Trypanosomatidae with the flagellum arising anterior to the
nucleus, and lacking an undulating membrane.
- prostate gland:
- secretory structure located within the cirrus pouch of Digenea.
- protandry:
- in hermaphrodites, the development of the male reproductive system before
the female system.
- protoscolex:
- the juvenile scolex formed by asexual budding within coenurus or hydatid
larvae of Cestoda.
- pseudocoelomate:
- possessing internal organs that float free within the coelom, not covered
by a peritoneum.
- pseudocyst:
- an intracellular accumulation of protozoans causing enlargement of the host
cell and giving the appearance of a cyst, but not surrounded by a cyst wall of
parasite origin.
- pseudopodium:
- an extension of the body of Protozoa used for locomotion.
- pseudosucker:
- a modification of the body surface that functions as a sucker but bears no
morphological resemblance to one.
- pupa:
- a life cycle stage in insects in which major morphological transformations
from a worm-like larva to a winged adult occur.
- pyriform:
- tear-drop shaped.