Medical Parasitology Lecture 1 - Structure, Morphology & Classification of Parasites (Flashcards)

Flashcards on the Structure, Morphology and Classification of Parasites

The relatively large size of parasites compared to other microbial agents makes usable their prominent structure and morphology as an aid in identification and subsequently, __.

definite diagnosis

The __ of parasites however enhances teaching and naming.

classifying

The basic body organization of protozoans consists of an external __ which encloses the cytoplasm and nucleus.

plasma membrane

Some protozoans may have one or more __.

nuclei

Some protozoans may have two types of nuclei; larger __ and smaller micronuclei.

macronuclei

__ are analogous to multicellular/metazoan organs for protozoans.

Organelles

__ containing food material are in various states of digestion

Vacuoles

Flagella aid in __; one or more.

swimming

__ are shorter than flagella and numerous.

Cilia

__ enable crawling and are temporary extensions of the cytoplasm which elongate the plasma membrane.

Pseudopodia

The basic features of all metazoans (helminthes of medical importance of interest) are eukaryotic, invertebrates, tube-like or flattened bodies, bilateral symmetry, and __.

triploblastic

Flatworms are __ and do not have body cavities.

acoelomate

Roundworms are __ with body cavities not enclosed by mesoderm.

pseudocoelomate

Morphology includes size, shape, color and __ of different organelles in different parasites at various stages of their development.

position

Morphology helps to identify the different __ of development.

stages

Morphology helps to differentiate between __ and commensal organisms.

pathogenic

Protozoans are small, eukaryotes, unicellular, and size microns in length up to about __.

1 mm

A single protozoan cell carries out all the functions such as digestion, respiration, __, reproduction, etc.

excretion

Most protozoans go through at least two morphologies: trophozoites which are __ stages and cysts.

feeding

Cysts are __ stages enclosed within a membrane to resist conditions in the external environment.

transmission

Arthropods are segmented, bilaterally symmetrical, and __.

chittinous exoskeleton

Arthropods have paired, __ appendages.

jointed

Helminths are larger organisms and a group of special cells carry out reproduction, digestion, __ , etc.

excretion

Most helminths are macroscopic, however identification frequently requires __ examination of their eggs.

microscopic

Helminths may be __ (Asc-) or flat (platy-).

round

The three main classifications of parasites are protozoans, helminths, and __.

arthropods

Protozoans are classified based on __.

locomotion

The four classifications of protozoans are flagellates, ciliates, amoeba and __.

sporozoans

__ use flagella which undulate to propel the cell through liquid environments.

Flagellates

__ are ‘whip-like’ extensions of the cell membrane with an inner core of microtubules arranged in a specific 2+9 configuration.

Flagella

Ciliates have ‘hair-like’ extensions of the __ which undulate allowing cells to swim in fluids.

cell membrane

Amoeba use __ to creep or crawl over solid substrates.

pseudopodia

Many sporozoans pre-spore stages move using tiny undulating ridges or waves in the __ imparting a forward gliding motion.

cell membrane

Sporozoans were not originally recognized on the basis of their locomotion, but because they all formed non-motile __ as transmission stages.

spores

Trematodes (Flukes) and Cestodes (Tapeworms) are classifications of __.

Platyhelminths

Nematodes (Asc; cavity) are __ worms.

round

Trematodes / Flukes have small flat __leaf-like bodies.

dorsoventrally

Trematodes / Flukes have oral and __ suckers.

ventral

Trematodes / Flukes have a __ sac-like gut.

blind

Trematodes / Flukes are __ flattened and have bilateral symmetry.

dorsoventrally

Cestodes/ Tapeworms are long flat __ bodies.

ribbon-like

Cestodes/ Tapeworms have a single __ holdfast organ (scolex).

anterior

Cestodes/ Tapeworms are __ and each segment contains both male and female organs.

hermaphroditic

Roundworms have round, __ bodies.

cylindrical

Roundworms have a complete __ (mouth and anus).

digestive tract

Roundworms have a cuticular body which is a non-cellular, __ coat.

resistant

Roundworms have Male that has __ tail.

coiled

Pin worms (E. vermicularis), Round worms (A. lumbricoides), Thread worms (S. stercoralis) are all classifications of __.

Nematodes

Hook worms (A. duodenale ), Whip worms (T. trichuris), Guinea worms (D. medinensis) are all classifications of __.

Nematodes

Filarial worms (O. volvulus ) are a classification of __.

Nematodes

The __ of a parasite is the arrangement or organization of parts to form an organ, system, or living thing.

structure