Lesson 7.3: Parasites

Parasite

Do not kill their host but lives in/on their host for an extended period

Protozoa, Helminths, Ectoparasites

3 Main Classes of Parasites

Protozoa

Microscopic & once-celled organisms that can infect & multiply in human beings (Free-living/parasitic in nature)

Aqueous Environment & Soil

Where protozoa are abundant

Flagellates, Ciliates, Amoebae

3 Groups of Protozoa

Flagellates

Move with the help of whip-like structures

Flagella

Whip-like structures

Ciliates

Move by using hair-like structures

Cilia

Hair-like structures

Amoeba

Move by the use of foot-like structures

Pseudopodia

Foot-like structures

Sessile

Protozoa that do not move

Sarcodina, Mastigophora, Ciliophora, Sporozoa

4 Groups of Infectious Protozoa based on Mode of Movement

Amoeba

Example of Sarcodina

Plasmodium & Cryptosporidium

Examples of Sporozoa

Helminths

Large & multicellular organisms that are visible to the naked eye in their adult stages (Free-living/parasitic in nature)

Adult Helminths

Helminths that cannot multiply in humans

Flatworms, Acanthocephalins, Roundworms

3 Main Groups of Helminths

Flatworms

Include nematoes & cestodes

Acanthocephalins

Thorny-headed worms

Roundworms

Their adults forms can reside in the gastrointestinal tract, blood, lymphatic system, or sub-cutaneous tissues

Ectoparasites

Organisms that attach/burrow into the skin & remain there for a relatively long time period (Blood sucking arthropods)

Mosquitoes

Example of blood-sucking arthropods

Ticks, Fleas, Lice, Mites

Examples of ectoparasites